The late 60’s and early 70’s ushered in an era that will never be forgotten, especially in the automotive world. It was a time when gas was cheap, steel was plenty, and the era of the V8 was in full force. The “big three” produced a variety of muscle cars all touting big horsepower, burning rubber, and drive-in movies.

Today, we marvel at these creations. We collect, modify, and cherish vehicles that were once bought as day to day creature comforts. It’s an obsession that drives an industry solely dedicated to keeping an era once past, alive and thriving in the 21st century. So, as an enthusiast, it only makes sense to own a piece of this era and give it a rightful place once again on the road, track, or showroom floor.

This article will discuss the experience of owning a 40 year old car; a project that to restore it back to life, in honor of a great era.

'71 Dodge Dart Swinger 318... Lots of potential!

Project Poison Dart: ’71 Dodge Dart Swinger

It took nearly four months of searching in Southern California to find a decent Dodge Dart. We had $5,000 total to spend and wanted to find something in good shape, running and drivable. It’s easy to get over your head when choosing a project car, not to mention hard on the wallet. We chose the Dodge Dart for a couple of reasons.

Number one, we’ve developed into a die hard Mopar fan, owning a ’07 Dodge Magnum R/T and a new ’11 Dodge Durango. Number two, it’s a car that has some real potential without the big collector car price. And it fit in our small third car garage very nicely!

In 1971, the Dodge Dart Swinger 2-door hardtop was released with a 318, 340, and slant six engine and a factory 4-speed automatic transmission. In our case, this particular Swinger had the popular 318 V8.

The Dodge 318 V8 engine was produced in Flint, Michigan from ’67 to ’02. The 318 was not just limited to Dodges, but also powered Plymouth and Chrysler cars as well. The engine is remarkably efficient, durable, and proved to be Chrysler’s mainstay for many of its vehicles over the decades, including the Dart.

This ’71 Dart Swinger lived out in Pomona, Ca and belonged to a young man who often drove it back and forth to the beach with his surfboard. The overall mechanical condition of the car was questionable and it appeared it was maintained enough just to keep it running. It’s original B3 paint is covered up by a secondary dark blue paint job that looked as if it was done in someones garage. The interior is complete, the floorboards are solid, and the car is running. It’s the ideal car for someone looking for a restoration project without having to start from the ground up.

When Buying Your First Project Car, Make Sure To:

1. Determine your budget beforehand: How much money can you afford to spend?
2. Decide your build theme. Want a full-time racer or just a street/strip car? A restoration or autocross car? It’s up to you.
3. Write a list of cars that interest you. Don’t buy just anything. Do you like Mustangs? Pontiacs? Mopars?
4. Open your mouth. Talk to those who have cars that you like. Chances are, they’ll know where other cars are for sale.
5. Don’t fall in love with paint. Paint can cover a lot of ugliness.
6. The more stock, the better. Look for the factory radio, gauges, etc. If the owner has tampered with the wiring, chances are they’ve messed with a lot more.
7. Running or near-to-running condition is preferred but not mandatory. If it doesn’t run doesn’t mean it can’t ever. Don’t be discouraged.
8. Make sure you have the space to store and work on your car. Wrenching in your apartment parking lot is no fun.
9. Tools. You can never have enough of them and they never depreciate in usefulness.
10. Don’t be afraid to get your hands dirty. You’ll be happier that you did it yourself.

Mandatory Maintenance

The Dart up on the powerTV Bendpak lift.

With 2012 marking the Dart’s 41st birthday, there are some elements of the vehicle that could use some careful inspection and possible replacement. With the objective in mind, we chose a select amount of maintenance and repair goals to kick off the project.

All of the work we performed on the ’71 Dart Swinger can be done within a day and is fairly simple. It requires a basic set of wrenches, a lift or jack stands, a used oil container, and a good set of gloves.

While it may be maintenance, we still get to play with some pretty fun parts that mingle the old with the new. Synthetic lubricants were not readily available back in the day and neither were the advancements in air filter technology that we have today, so it’s going to be some what of a performance upgrade as well.

Since we’re obviously making this the first of many stops to the shop for this project car, we also made sure to get a baseline on the dyno. With a 128 horsepower and 192 ft. lbs of torque, we were pleasantly surprised that the car, over 40 years, only lost about 15 horsepower. Not bad!

The '71 Dart on the dyno at the powerTV garage spat out a decent 128hp and 192 ft. lbs. of torque.

Royal Purple lubricants ready to replace the original OEM oils used in the Dart.

Replace The Lubricants

This was a no brainer. It’s commonly a best practice to replace the fluids in any vehicle you purchase, especially a older one simply because you can never count on the previous owner to adhere to regular scheduled maintenance. We opted for Royal Purple for the Dart’s engine, transmission, and gear lubricants.

Check out the nasty gear and transmission oil from a 40 year old car!

Replacing the lubricants in a '71 Dodge Dart Swinger with Royal Purple lubricants.

For the engine oil, Royal Purple recommended their Royal Purple HPS Series Synthetic Motor Oil. Royal Purple HPS Series motor oil is specifically formulated to maximize performance and meet the demands of high performance and modified engines. It’s fortified with a high level of zinc/phosphorus anti-wear additive and Royal Purple’s proprietary Synerlec additive technology. We used a 10W-30 viscosity oil.

Royal Purple ATF transmission oil.

We got a hold of Royal Purple’s Max Gear synthetic gear oil (75W-90 weight). Max Gear is an ultra-tough automotive gear oil. It’s designed to maximize power and provide unsurpassed protection to heavily loaded gears.

It makes gears run smoother, quieter, cooler and longer without overhauls. We’ll get to the details and steps we took for replacing the gear oil later in the story.

The last lubricant is set aside for the Dart’s 904 Automatic transmission, Royal Purple’s Max ATF Transmission Oil. Max ATF is a synthetic, high-performance, automatic transmission fluid. It’s low co-efficient of friction and high film strength help to dramatically reduce heat and wear.

Additionally, Royal Purple claims that their Max ATF is more oxidation stable than other transmission fluids for longer fluid life. Automatic transmissions generate a great deal of heat. It’s a must to replace the transmission oil on the Dart to ensure an extended life for the 904. More than 90 percent of all automatic transmission failures are caused by overheating; a 20°F reduction in fluid temperature can double the life of the transmission.

The engine mount was completely split in half causing some serious vibrations.

Engine And Transmission Mounts

The ’71 Dart has nothing out of the ordinary when it comes to the mounts for the engine and transmission crossmember. However, after 40 years, the mounts on this Dart are shot. The passenger side engine mount is completely torn apart and the driver side is not in much better shape. The transmission mount is cracked and crumbling away. Definitely a good move to replace these.

The engine and transmission mounts are readily available at most auto-parts stores. Since the Dart uses fairly generic style mounts, it was easy to find and they were even in stock at NAPA for under $8 a piece. Not only are these very easy parts to hunt down, but replace. Using simple hand tools and a floor jack, you can swap out your engine mounts and cross-member mount within a couple of hours.

Replacing the engine and transmission mounts is a must for a 40 year old car. The easiest way of accomplishing this is with a floor jack and a wood block to prop up the transmission while changing the cross-member mount or each side of the engine swapping the motor mounts...or you could use a two-post lift like we did.

K&N Xtreme Air Flow Top Filter specially designed to breath from all angles.

Air Filter

The previous owner of the ’71 Dart Swinger had completed some small modifications and improvements under the hood. The air filter assembly, valve covers, and ignition had all been replaced some time ago and dressed up the engine a bit more than stock. However, the air filter assembly seemed like it had seen better days. Rust and chipped paint plagued what was once a nice looking assembly from Mopar.

We turned to K&N for a new filter and assembly. Since the car only has a two-barrel carburetor, the more air flow we could give the engine, the better. K&N’s 14 inch diameter X-Stream Air Flow Top (which includes both the filter and assembly) fit the bill. All we had to do was simply drop it on the top of the carburetor.

The K&N Xtreme Top Air Filter fits nicely on the Dart's 318.

The K&N XStream Air Flow Tops replace the top of your existing round filter and add a new dimension to engine breathing by feeding your engine all the air it can use. Not only does the K&N XStream add filter area, it actually redirects airflow inside the filter to pull in more air through the side pleats for even greater performance efficiency.

They are washable and reusable just like other K&N Air Filters. Cleanable and reusable, the XStream Air Flow Top filter delivers outstanding engine protection and comes in a wide range of applications. Sizes include 9, 11, 14 and 16-inch diameters. The 14-inch tops are available in anodized black, red, blue or chrome trim ring. I chose the chrome trim.

A compression test will tell you the pressure and the consistency of the pressure inside each chamber.

Compression Testing

To make sure the 318 V8 Wedge engine is in good working order, it’s a good idea to check the internals, specifically compression.

A compression test will tell you if your engine has good compression or not.

An engine is essentially a self-powered air pump, so it needs good compression to run efficiently, cleanly and to start easily.

As a rule, most engines should have 140 to 160 lbs. of cranking compression with no more than 10% difference between any of the cylinders.

Low compression in one cylinder usually indicates a bad exhaust valve. Low compression in two adjacent cylinders typically means you have a bad head gasket.

Low compression in all cylinders would tell you the rings and cylinders are worn and the engine needs to be overhauled.

With a good average all within range of being normal, we could rest assure that the Dart’s 318 engine had some life left in it and will survive long enough to get us to and from the shop until we decide the direction we go with in terms of a new powertrain.

Other Filters, Gaskets, and Cleaning

The final maintenance is pretty standard and should be done for all vehicles you own in your lifetime.

Cleaning the carb is going to help solve our starting problem allowing fuel to flow freely into the intake.

Replacing filters, gaskets, and regular cleaning will keep the wear and tear of the vehicle to a minimum and extend the life of the car dramatically. For the Dart, the valve cover gaskets, transmission filter, and carburetor needed some attention specifically.

The valve cover gaskets were worn and cracking, so a simple replacement was needed. These are also something easily attained at a local auto parts store. With new transmission oil, it’s also a good idea to replace the transmission filter.

We purchased a Hastings transmission filter online and it should last the transmissions remaining lifetime. The carburetor on the Dart is a two-barrel that seems to be in decent shape, however, it looks like it had never been cleaned. So we added it to the list of items to be cleaned.

Replacement gaskets are a inexpensive yet important step to take to keep your car running smooth.

The carburetor was at the top of the priority list for some cleaning. The Dart’s 318 was having some trouble starting up cold and we suspected the injectors could use a good run through. With carburetor unmounted from the intake manifold, carb cleaner and a steal brush were used to clean large build ups of dirt, dry fuel, and excess engine grime.

Ready To Run: Driver’s Perspective

Typically, when we would go to start the Dart, it would take at least five to six turns on the key along with pumping the gas to get the car to start. With everything checked off the list for the maintenance project on our ’71 Dart, it was time to reap the benefits. Once the car was lowered down off the lift, she fired right up! We can now drive it with piece of mind knowing that the car has some durability left.

We’re still working on the plans for the car. There are so many directions to take it, so luckily all we have to do is pick out the ones we don’t like and then go from there. Here are some different options we’re considering in terms of the overall look of the car and it’s purpose. Maybe you as the reader can provide some insight!

Taking the time to allow a clutch to properly break in is one of the most important things you can do to insure that it lives a long and grippy life inside your bell housing. “Professor” Will Baty, from Centerforce explains, “Just driving around town, taking it easy for about 500 miles is the best way to seat a clutch in. Not 500 miles on the freeway, or going out drag racing. We want the clutch to be heat cycled as many times possible without over heating it, and with minimal power applied. The clutch disc has high and low spots on the friction material, and you want to reduce the high spots and embed the friction material to the pressure plate and flywheel. You want to create a nice even surface on the disc.”

Simple, right? No highway driving and no beating on the clutch for the first 500 miles.

If you want to get the most out of you clutch, and have it last as long as possible, you need to break it in properly.

Now, if you get impatient and decide to get rough with the clutch before it’s been properly seated, there can be some pretty bad consequences, the worst of which is glazing the disc. And no, we aren’t talking about covering it in the sugary goodness that donuts have on them.

Baty says, “When a disc is glazed, the friction material is essentially polished smooth because the driver was too hard on the clutch before it was properly broken in. Once a clutch disc glazes, it loses its friction. It’s very much like sanding all the grit off of sand paper or a tire losing all its tread; it’s slick and won’t grip very well. Once the friction is gone from the disc, there is no getting it back, and you’ll have to replace the disc if you want your clutch to work properly again.”

Notice those shiny spots on the friction material? Yeah, that's not good. Someone got a little impatient and went drag racing with this clutch before it was properly seated, and glazed it.

That’s it for this class, but in the next installment of Centerforce University we will go over flywheel design and how to pick the right one for your car, so stay tuned!

The flywheel bolts to a flange on the crank shaft, and will always spin at the same speed as the engine.

A clutch can be one of those mysterious parts where you might know what function it performs, but might not know exactly how it works. We asked Will Baty of Centerforce Clutches to give us a run-down of what is going on inside the bellhousing, and some of the factors that can affect a clutch’s performance.

The pressure plate bolts to the flywheel, and the clutch disc is sandwiched in between.

“A clutch creates the basic link between the engine and the transmission, and is the key to how the power of the engine is transferred to the transmission on its way to the wheels. The clutch’s main function is to temporarily disengage the engine from the transmission – allowing the engine to spin at a different rate – and allowing the driver to easily shift gears,” Baty explains.

The disc is where the magic really happens. The clutch disc is kind of like a big round brake pad, only instead of making things stop, it makes the transmission spin when the friction material grips the flywheel.

A clutch is actually several components working together to allow you to shift. Baty says, “There are four key components to a clutch system that allow it to do its job; the flywheel, the clutch disc, the pressure plate, and the throw-out bearing. All four work together as one unit. When you press the clutch pedal, the throw-out-bearing presses against the diaphragm fingers of the pressure plate, and the diaphragm raises, lifting the pressure plate ring away from the disc. The disc disengages, and you can shift.”

The throw out bearing pushes against the pressure plate's fingers when you press the clutch pedal. The fingers are "levers" that lift the pressure plate away from the clutch disc.

Clutches are able to operate thanks to friction and clamping forces. Friction keeps the clutch disc gripping the flywheel, and the clamp load of the pressure plate keeps the disc pressed to the flywheel, or allows it to release when you press the clutch. Baty tells us, “The amount of clamp load that the pressure plate generates, along with the type of friction material on the disc, are what determines the holding capacity of a clutch. There are many grades of friction material, or in the clutch world we call the ‘point of friction’, that can increase or decrease the clutch’s holding capacity. The higher the friction, the more holding capacity in the clutch, but typically the drivability will suffer. Another factor is the size and overall diameter of the clutch assembly; the larger the assembly, typically the more holding capacity, even at a lower pressure and point of friction.”

Stay tuned ye “scholars of shift” – in our next installment of Centerforce University, we will talk about the proper way to break-in a clutch.

You know it as well as I do—a stick transmission is the only way to go in a Mustang. In the Fox-body 5.0 days, opting for an automatic just killed performance, while ordering the 5-speed made the car a riot to drive. While technology has closed that gap in recent years, it’s still really no contest; the automatic is boring and slow, and the 5- (or 6-) speed is fast. The only exception, maybe, is if you’re building a 900 horsepower, drag-only car, in which case sometimes a built C4 or ‘glide may be the hot ticket. But for those of us with street cars, the 5-speed is the ticket. If you are inline for an upgrade, you have come to the right place, as we have enlisted the help of the folks from Tremec transmissions to bring you a guide to picking the right tranny.

Fox Body and SN-95 Transmission History

The Fox-body Mustang came onto the scene in 1979 but it was a wheezer until the return of the GT in 1982. In ’83 it got even better, with a Borg-Warner T-5 5-speed trans replacing the previous 4-speed overdrive. The T-5 was standard in all Mustangs from that point until the mid-’90s, at which point Tremec bought B-W’s transmission business and took it over. For the better, we say. Tremec continued to supply the T-5 for 6-cylinder Mustangs as well as a beefier T-45 for the V8 cars, before getting serious with both OE and aftermarket transmission offerings for the Mustang. But let’s back up and look at the earlier boxes, shall we?

This is the T-5, variations of which came in V8 Mustangs from 1983 until 1995.

Holding true to engineering and production line changes throughout a car’s life, not all Borg-Warner T-5s are the same. The main split in the early boxes is the difference between the World Class (WC) and non-World Class (NWC) transmissions. In ’83 and ’84, the Mustang had the basic T-5, or non-World Class, unit, which was rated at 265 lb-ft of torque capacity. In ’85 came the WC T-5 with a deeper 3.35:1 first gear (compared to 2.95:1 for the NWC) and better internals for smoother shifting. The torque rating stayed the same, though. There was also a T-5 used behind the turbocharged 4-cylinder cars, but ignore it—it won’t handle the power of even an average 5.0.

From 1990 to ’93, the WC gear set was made stronger with higher nickel content and slightly lowered second and third gear ratios. The torque rating jumped to 300 lb-ft. That gained another 10 lb-ft in the ’93 Cobra-spec T-5 that used a front tapered output bearing and steel front bearing retainer. That same year, Ford released a service unit (sold primarily through Ford Racing) that was even better; the Z-spec T-5. It had a 2.95 first gear, .63 overdrive, hardened gears, a short-throw shifter, a steel front bearing retainer, tapered output shaft bearing…basically all the good stuff was thrown in this transmission. Appropriately, the torque rating went up to 330 lb-ft, and was said to handle 450 horsepower (without slicks and a 5,000 rpm clutch drop anyway).

The 5.0-liter SN95 Mustangs of 1994 and ’95 were the last to see a T-5 in a V8 Mustang (though it was still used in the V6 cars until years later). In order to put the shifter in a comfortable place for the driver, Ford increased the bell housing depth and therefore the input shaft length. They also killed the neutral safety switch. The 3.8L V6 cars still used the T-5, with a .68:1 overdrive, but thanks to ever-increasing electronic controls on new cars, it was devoid of a mechanical speedometer drive. Otherwise, it was the same as the non-Cobra V8 trans.

Then Comes Tremec

Ford went to Tremec (stands for Transmission and Mechanical Equipment) to build a stout transmission for the limited-edition ’95 Cobra R, and they responded with the TR-3550 5-speed. Just a year or so later, Tremec took control of Borg-Warner’s transmission production and supplied the manual transmissions to the Mustang from then on.

With the debut of the modular motor in 1996, the transmission changed again and became the T-45. The bellhousing was now integral with the gearbox, and had a different bolt pattern so that it wouldn’t mate to a 5.0L. Not without a ton of work anyway. Internally it was very similar to the T-5, though nothing interchanges between them, and it was rated at 330 lb-ft. A common gripe about the T-45 is the reverse gear: though it was synchronized, many users complained that getting it into reverse was a gear-crashing exercise.

The 3650 as found in the modular-powered, S197 Mustangs

When the “New Edge” Mustang came out in 1999, the mod motor was still backed by the T-45, a straight carryover from the ’96-’98 cars. But when the Mustang was redesigned again for the ’05 model year, the T-45 was replaced with the 3650 that had been used in the prior, hotter Mustangs.

The internals were basically the same as the T-45, but thanks to Ford’s intense efforts to eliminate noise, vibration, and harshness (NVH), the shifter was moved off of the transmission, in what Tremec calls a semi-remote shifter. Immediately, racers and anyone who tried to bang shift the trans complained about missed shifts and overall sloppy shifting. Aftermarket shifters and fixes helped, but only a little.

Tremec And The Aftermarket

Up until the ’03 Cobra came along and forever changed the way the masses viewed Ford’s Modular engine, many enthusiasts were still busy trying to ring out the most they could from their Windsor-based combos. And as all Blue Oval faithful know, the capabilities of the stock T-5 had long been exceeded. Following the success of the TR-3550 in the ’95 Cobra R, Tremec made the unit available to the Mustang aftermarket; again touting it as an effective T-5 replacement with 350 lb-ft. of torque capacity.

The 3550 becomes the TKO

A series of revisions quickly followed, and in ’97 the 3550 was re-released as the 425 lb-ft TKO. Benefiting from upgraded input and output shafts, a bolstered main case, revised gearing, and upgraded materials, the TKO was a near instant success in Ford drag racing circles. Tremec quickly spread its influence into the road-racing arena as well, with the release of the TKO-II, which featured a 0.82 overdrive (3550 and TKO had a 0.68) for high-speed pulling power and 475 lb-ft. of torque capacity.

Tremec sells bellhousings that bolt the TKO-500/600 onto popular engine combinations, like small block Fords and Chevys.

The TKO raged on unchanged for several more years, until Tremec was all but forced to address the needs of Brand X (GM) customers around 2002. It seemed that word had gotten around on the street about the 5-speed brute that all the serious Fox-body guys were using, and they too liked the idea of a tough stick-shift with overdrive. The release of the TKO-500 and TKO-600 in 2004 was what followed. Offering multiple shift locations, dual speedo pickups (mechanical and electric), a variety of crossmember mounting configurations, and up to 600 lb-ft. of tire shredding torque capacity, no longer would the TKO be strictly the darling of the Ford world, but insanely popular in early GM and Mopar segments as well.

The main difference between the 500 and 600 is the gear ratio: The 500 uses a 3.27:1 first, while the 600 has a 2.87:1 ratio. The lower the ratio the bigger the gear, so with more surface area comes more strength and a higher torque rating. Also the 600 is only available with a 26-spline input shaft, whereas you can get a 10-spline input in the 500 (though 26-spline is also offered). The 10-spline input shaft is standard for all the Mustangs, but is weaker than the 26-spine, so the only reason you’d go with the 10-spline, in our opinion, is if you already have a 10-spline clutch.

Adding Another Gear with the T-56

The TKO would eventually go on to become the transmission of choice for nearly all serious road-going manually-shifted muscle cars, regardless of brand, selling over 60,000 copies to date. Meanwhile, as more race-bred technology found its way to the street and the advent of computer-controlled horsepower gave street performance enthusiasts an easy way to put it all to use, the Tremec T-56 gained momentum as an all around performance favorite thanks to the success it had realized in applications like the ’03-’04 Cobra (as well as the Viper, Corvette, and Camaro/Firebird).

(Left) The T-56 6-speed as found in the ’03-’04 Cobra. (Right) The rugged TKO II road-race transmission.

While perhaps less than desirable for hardcore drag racing due to its weight and virtually useless (on the dragstrip) fifth and sixth gears, the T-56 offered an exceptional balance of strength, smoothness, and practicality for many a high-horsepower street car. The only real problem was a lack of flexibility for early swaps with shifter locations that may work great for a Terminator Cobra, but not so well for a 4-valve Fairlane conversion, etc.

Tremec’s Hardcore T-56 Magnum

Here’s a pre-production image of the T-56 Magnum with bellhousing and crossmember for S197 (including 2011+) Mustangs, which are available from Tremec. Check out their website (Tremec.com) for shifters, overdrive gearsets, driveshaft yokes, and lots more.

So in 2009 Tremec answered the car crafters’ call with the debut of the T-56 Magnum 6-speed. Based on the latest and greatest O.E. technology, the Magnum was (and is) based on the TR-6060 family of transmissions that first made its appearance behind the supercharged 5.4 of the ’07 Shelby GT500. Conservatively rated for up to 700 lb-ft. of torque (up from 450 of the original T-56), the new Magnum offered the crisp shifts and refinement of a world class supercar, combined with all the flexible features of the utilitarian TKO. Designed heavily with the Fox and SN95 Mustang market in mind, the Magnum is an easy and worthwhile swap for any heavy-hitting Fox-based vehicle from 1979-2004.

The newest kid on the Tremec block is an extended-length version of the Magnum 6-speed specifically designed for 2005-up S197 Mustangs. Tremec’s Nate Tovey said, “This is Tremec’s first big foray back into the aftermarket. Since 2005, guys haven’t had a viable transmission for cars with big power, like high-horsepower blower and turbo cars.” The extended-length Magnum features a unique direct-shift extension housing that replaces the notoriously sloppy semi-remote units that have come from the factory since the launch of the S197 Mustang in 2005. This goes back to the significant changes we mentioned regarding the 3650 above, which were mainly centered around the new vehicle architecture.

The Upgrade Path For Your Mustang Generation

Aftermarket companies like D&D have T-56 retrofit kits for all '79+ Mustangs.

Fox Body (’79-’93)
• Factory Transmissions: T-5 Non World Class in ‘’83-’84, World Class from ’85-’93
• Best Replacement Junkyard Trans: Look for a T-5 from a ’90-’93 model, as they’re a little bit stronger, especially a Cobra World Class T-5
• New Tremec Offerings: TKO-500 and 600, T-56 Magnum
• Supporting Parts Needed: The TKO is a bolt-in but you’ll need a TKO-specific bellhousing, which is sold by many aftermarket companies. The stock crossmember is used. Also need a 31-spine driveshaft yoke (available from Tremec) Driveshaft length is stock. The T-56 Magnum will need a specific bellhousing as well, aftermarket driveshaft, 26 spline clutch kit and transmission cross member.

SN-95 (’94-’98)
• Factory Transmissions: T-5 ’94-’95 are the same, and T-45 ’96-’98 are too.
• Best Replacement Junkyard Trans: Just find the lowest-mileage one you can. ’94-95 and ’96-98 won’t interchange.
• New Tremec Offerings: TKO 500 and 600, T-56 Magnum
• Supporting Parts Needed: The TKO is a bit shorter than this model’s T-5, but many companies sell a small spacer that bolts to the back of the driveshaft to make up the difference. The mounting pad is a little higher too, which can be taken care of with some body washers or a similar spacer. The T-56 Magnum will need a specific bellhousing as well, aftermarket driveshaft, 26 spline clutch kit and transmission cross member.

 SN-95 ‘New Edge’ (’99-’04)
• Factory Transmissions: T-45 5-speed (1999-2000), 3650 5-speed (2001-2010), T-56 6-speed (2000 Cobra R)
• Best Replacement Junkyard Trans: Get the latest one you can, since Tremec experienced some minor issues with the early units. The T-45 and 3650 do not interchange without a costly driveshaft conversion. The GT500 6060 is also an available upgrade but requires a new driveshaft and 26 spline clutch disc.
• New Tremec Offerings: T56 Magnum
• Supporting Parts Needed: The T-56 Magnum will need a specific bellhousing as well, aftermarket driveshaft, 26 spline clutch kit and transmission cross member.

Tremec has a new T-56 Magnum kit designed for 2005-up Mustangs and come with a bellhousing and transmission crossmember, though an aftermarket driveshaft and clutch kit is needed. 2011+ Mustangs will need a speedo signal converter too.

S197 (’05-’10)
• Factory Transmissions: The 3650
• Best Replacement Junkyard Trans: The GT500 6060 is an available upgrade but requires a 26 spline clutch disc, new shifter, and crossmember. Stock 3650 driveshaft fits.
• New Tremec Offerings: T56 Magnum
• Supporting Parts Needed: The Magnum kit from Tremec (discussed above) comes with everything you need except a 26 spline disc and yoke-type driveshaft.

S197 5.0 (’11+)
• Factory Transmissions: Getrag MT-82
• Best Replacement Junkyard Trans: None
• New Tremec Offerings: T56 Magnum
• Supporting Parts Needed: The Magnum kit from Tremec comes with everything you need except a 26 spline clutch kit that must have the same stack up height as a 3650, yoke-type driveshaft, and speedo signal converter (converting 33 tooth hall effect to 12 tooth tone effect).

Aside from offering superior shift performance, other important features of the Magnum XL include:

• A slip yoke-style rear interface that eliminates the factory fixed-flange and allows users to run a one-piece driveshaft. This setup is not only stronger than the factory 2-piece arrangement, but reduces rotating mass by nearly 20 lbs. Additionally, an upgraded aluminum or carbon fiber driveshaft is a much less expensive proposition when using a 1-piece shaft.
• An SFI-certified steel bellhousing that is included with the transmission directly from Tremec.
• A swap-specific crossmember and mount that requires no modifications whatsoever to the vehicle, and maintains proper driveline angles.
• Six forward gears with two optional ratio sets (see notes below)
• Triple cone synchronizers on gears 1-4, double cone synchros for fifth, sixth, and reverse. (all use sintered bronze friction elements except 2nd gear, which uses carbon–not carbon fiber).
• Deep input shaft splines to accommodate dual and even triple disc clutches.
• A stout 700 lb-ft. of torque capacity.

Thank Ford's NVH engineers for this beauty. This is the factory semi-remote shifter and fixed flange output on the ’05-up 5-speeds. Sloppy shifting is guaranteed with this setup, but Tremec’s new extended-length Magnum 6-speed solves it.

Other Important Notes:

• Available gear ratios for the Magnum XL will be as follows:
• Part # TUET11430- 2.66, 1.78, 1.30, 1.00, 0.74, 0.50
• Part # TUET11940- 2.97, 2.10, 1.46, 1.00, 0.80, 0.63
• All Magnum series transmissions feature interchangeable fifth and sixth gears, allowing users to swap overdrive ratios or create their own combination. Both drive and driven gears must be replaced.
• The Magnum XL nomenclature is being introduced to eliminate the S197 Magnum title in lieu of trade name concerns, and because the new design will also eventually be applied to the late-model Camaro and Challenger markets.
• Performing a Magnum XL swap in a 2005-2010 Mustang requires no special modifications.
• Performing a Magnum XL swap in a 2011-up Mustang requires users to install an electronic speed calibrator into the factory harness to correct the speedometer. This part will eventually be available from Tremec, but will initially be sourced and sold by Tremec distributors.
• All Magnum XL swaps will require a 26-spline clutch disc and 1-piece driveshaft; not available from Tremec.
• All Magnum XL swaps will allow users to re-use their factory hydraulic throwout bearings. However, due to their shorter length, GT500 bearings will require a special spacer or shims.

Gear ratio chart - click the image for a larger version.

From Junk Yard to New, Tremec has it all

Tremec transmissions is a namesake amongst the Mustang community, and regardless if it is a T-5 out of your Fox body or a T-56 Magnum swap in a 2011 Mustang, there are many ways to improve the durability of your Mustang’s drivetrain.  There are many junk yard finds that serve as good upgrades, but nothing can top a brand new heavy duty Tremec transmission in your late-model muscle car.

Our ’65 Mustang Project: “Biting the Bullitt” has been under the knife in the powerTV shop for the last few months getting a brand new suspension along with fitting the engine and transmission, as we get closer to firing it up for the first time.

In our previous installation articles we installed a TCI Custom IFS front suspension, along with a complete rear suspension from Strange and Calvert, plus capped off with a set of Wilwood brakes, Weld RT wheels, and Mickey Thompson tires.

We started with the TCI Custom IFS because we simply did not want to deal with working on a supercharged Windsor in a first gen Mustang’s overly tight engine bay.  Also, it updates the front suspension to a more conventional upper/lower control arm combination.

For the rear suspension, we knew the stock 7.5-inch rear end and according suspension pieces weren’t going to keep up with the 1000hp+ we were going to be throwing down.  A Strange 9-inch fit nicely in place, harnessing all the power we can throw at it.  Keeping the power transmitted properly to the pavement, we turned to Calvert Racing and their complete line of rear suspension pieces.  Lastly, wanting to fit a 15×9 and 275/60 drag radial comfortably in the wheel wells, we mini tubbed the Mustang with Autoworks’ Mustang-specific mini tub kit.

Overdrive and Durability In One with TCI’s 4L80E

With the suspension completed we moved to test fitting the engine and transmission.  For the transmission, we wanted something that would be easy to drive on the freeway and be able to handle the power.  Unfortunately, a C4 is hard to build properly and we needed more gears than a Poweglide can offer.  We decided to go with TCI’s Super Streetfighter 4L80E 4-speed transmission.  Yes we know, it’s a GM transmission in a Ford, but this transmission setup is really sweet.

TCI makes a modular 4L80E transmission that fits a wide range of applications, with the SFI approved bell housing on ours designed for a Ford engine. The EZ-TCU allows us to program shift points for full automatic shifting, or a manual mode can be triggered and the two buttons on the Outlaw shifter act as up and downshifts.

It all starts with TCI’s modular case that allows a Ford SFI approved bell housing to be adapted straight to it.  That means no screwing around with spacer plates, everything bolts on and goes.

It is backed by a EZ-TCU and Outlaw shifter, which makes shifting a breeze because we simply don’t have to do anything! The EZ-TCU gives the Outlaw shifter the ability to be used in manual or automatic mode via the ratcheting shifter or the two push buttons on the shifter for up or down shifting.  While in drive mode, the EZ-TCU can be programmed to shift at any RPM you want, increasing consistency and keeping us in the power band between shifts.  There is even a switch that can be installed to regulate between soft (street) and firm (race) line pressures.

The 4L80E does depend on throttle position to work properly, so we opted for a TCI TPS sensor that drives straight from the carburetor’s throttle linkage and plugs directly into the EZ-TCU’s harness.

We knew it wasn’t going to be a direct fit for this much larger transmission, and rather then screw around with patch panels, we scalped the Mustang’s tunnel and installed a fresh sheet metal version that we formed in house that allows for complete functionality of the transmission linkage and cooler lines.

Since the TCI cross member already comes with engine mounts, there was no guesswork involved to get the small block in the car.  For the transmission mount, we turned to Chris Alston Chassisworks’ universal transmission mount kit. While they do offer the kit in different radiused bends, we opted for the straight tube and bent our own.  The kit also includes two clevis ends with tabs and a transmission mount bracket. It was really easy to install, especially since we had our Chris Alston subframe brace in place to mount the tabs to.

The 4L80E is a big boy. We didn't mess around with hammering the tunnel to try to make it work, rather we scalped the tunnel and installed a fresh sheet metal piece that even offers a little wiggle room. Chris Alston's universal transmission mount worked perfectly and we secured it to their subframe brace. With the tunnel finished, we cleaned the entire bottom of the Mustang and undercoated it with canned 3M undercoating spray. This really helps the appearance and also reduces further rusting.

Cooling and Fueling with Snow Performance, Aeroquip, Fuelab, Derale and AFCO

With the motor in place we moved to plumbing the fuel system with help from our friends from Fuelab and Aeroquip.  Instead of going with a fuel cell, we were lucky enough to buy Tim Grillot’s sumped stock tank he had built for his fastback.  Fuelab then supplied us with their 1800 hp capable variable speed EFI fuel pump, 1:1 regulator, pre and post filters.

It is important to run a EFI fuel pump on blow-through carbureted applications, since we will see nearly 25 PSI of fuel pressure under full boost. The other great benefit of Fuelab’s fuel pump technology is that it can be run in low speed for street duty and switch to high speed when you need it.  The pump can be wired for either a trigger or ground switch to activate. We will wire the pump to activate on the pump switch from the Snow Performance water/meth kit mounted in the trunk, so when the Snow pump activates around 4 psi of boost, the Fuelab pump will run in high speed instantly.

We needed to fit the largest possible radiator we could in our '65, so we turned to AFCO to build us a custom piece. The radiator secures into the frame rails at the bottom with dowels and threaded bungs on the front side that attach to the core support. The factory core support recess was cut out to gain much-needed clearance.

To feed the pump and motor we went with Aeroquip’s Starlite hoses and fittings. The Starlite racing hose is Aeroquip’s light weight racing hose, up to 45% lighter than steel braided.  But don’t think this hose isn’t strong; it is covered with flame resistant Nomex and ultra durable Kevlar. For line sizes, we went with -12 AN from the pump to the pre-filter with a -10 AN outlet and return line. We also used the Starlite hoses and fittings to connect our custom Canton oil separator to the valve cover’s welded bungs.

Since we knew we wanted to drive the Mustang around town without running into overheating issues, we turned to AFCO to build us a custom radiator to fill every bit of available space we had in the front of the Mustang. Fitting from frame rail to frame rail, this all-aluminum cross flow radiator locates into the frame rail with dowels and features threaded bungs on the front of the radiator so we can attach it directly to the core support. Before we could do that, we had to cut out the factory radiator’s mounting point and recess, gaining much-needed clearance to the motor.

A sumped stock tank was a simple solution for our fuel system. Since the fuel pump is mounted above the sump, Fuelab recommends adding a check valve right after the pump's outlet. The post fuel filter is mounted about two feet forward of the outlet onto the Chassisworks' subframe connectors. The rest of our fuel system consists of a Snow Performance Stage 3 water/meth injection kit, which we mounted the 2.5 gallon tank and pump opposite of our battery box.

With the supercharger and radiator in place, it is a tight fit, with as little as 2-1/4 inches of clearance in some spots.  We turned to Derale to build us a custom shroud that would place dual fans offset from each other in spots that would clear the supercharger drive system.  To aid with the building, we made a template of our front drive, complete with spacing to all the bolts and belts.

The Odds and Ends

With the fueling wrapped up and the cooling system nearly complete, we moved onto buttoning up other projects and prepping for wiring.

We made an electronics panel that mounts in place of the factory heater blower, allowing us to easily service any of the engine’s electronics.  Everything will be controlled by Racepak’s new SmartWire that is a fully programmable, automated relay board that contains no fuses.

The Racepak UDX display fit perfectly into the blank Mustang dash insert we purchased. The UDX will display all our critical sensor inputs as well as displaying our basic car functions like turn signals and lights.

Speaking of Racepak, we also went with their UDX series gauge cluster.  Outside of displaying all of our critical sensor outputs, it also serves duty like a traditional cluster with turn signal, fuel level, and high beam switch notification. We mounted the UDX into an ABS plastic panel that fits directly into our factory gauge cluster location.

Canton supplied us with this trick baffled oil catch can that vents to both valve covers.  Canton has the ability to build custom catch tanks with any options you desire.

The trunk was a suitable place to mount our Snow Performance 2.5 gallon reservoir, along with a simple bracket to hold the pump in place.  Opposite the tank is a Taylor battery box with an Optima Red Top Battery and emergency shut off switch mounted to the box.

We really didn’t want to install a cowl hood on the Mustang and opted for a classic teardrop hood from Maier Racing.  We did run into an issue with clearance to the intake pipe and opted to leave the pipe exposed from the outside…after a weekend polishing project, that is.

Biting the Bullitt is getting really close to running with a week’s worth of random tasks and a few days of wiring left before it is ready to run.  With a mere 300 hours into the project we are getting excited about making that first trip to the track for some solid nine-second passes.  Stay tuned to future updates and tech articles on our ’65 ‘Stang!

Putting power to the pavement is more than just stomping on the go-pedal, there are complex mechanical events that happen between your foot and the tires. It is a common thread in performance circles; the rear differential gets forsaken for the glory of the engine and transmission. Many street/strip cars get by on a stock posi-style diff, or God forbid, welded spider gears. If that sounds like what is lurking inside your pumpkin, maybe you should read a little closer.

Modern differentials come in many flavors—open, limited slip, locking, and spool (which is not even a differential). The open differential is not really “geared” for performance, so it’s out as is (see drop-ins below for open carrier upgrades). That leaves three. The spool locks the axles together permanently, similar to the low-buck welded-spiders, but in a safe way.

This eliminates the differentials main function of allowing one wheel to spin slower than the other when needed, specifically when turning. Spools are not the worst thing on the street, but they are pretty close. We are going to leave those out of this conversation too, sticking to true performance differentials— lockers and limited-slip (LSD).

Within these two styles there are quite a few different options. Each has their own pros and cons. Which one is best for your car? We talked to Jeff Saxton at Eaton Performance Products who helped us compile the details and put them right here for you to decide.

Eaton employs nearly 10,000 people in its Southfield, Michigan headquarters, its international Engineering, Research and Development centers in Marshall, Michigan; Turin, Italy; Baden Baden, Germany; Pune, India; and Shanghai, China and throughout its 30 manufacturing locations worldwide. Eaton also supplies nearly every automotive, vehicle and engine manufacturer in the world with its high-quality parts and services.

Besides the tires, the rear differential is the last line of defense against slow 60-foot times and lost traction, but like transmissions, differentials are steeped in mystery and voodoo magic, or are they?

Limited Slip Giving You The Slip?

Best known by the GM name “posi-traction,” the limited slip (LSD) has been used by just about every manufacturer at some point. This style of differential is designed to transfer power from “the wheel that slips to the wheel that grips,” or so the commercials used to say.

This is an upgrade from the open diff, which would send the power to the slipping wheel, not exactly the best thing for a tidy launch off the line. To do this, the LSD uses either gears or friction clutches to allow the axles to spin at different rates.

The LSD differential operates on three input torque states:

• Load
• No load
• Overrun

Under no load conditions, the LSD operates in static couple, similar to an open carrier.

What classifies the LSD is its overrun operation. Overrun is a sudden release of torque, such as hard on the throttle then jumping off. How the LSD reacts to overrun situations determines whether the LSD is a 1, 1.5, or 2 way; which is an important spec for a street car.

The shape of the ramp (or geometry of the tooth form) on the spider gears determines the LSD type. If the ramps are symmetrical, then the diff is a 2-way. If they look like saw-teeth (one vertical, one sloped) then the LSD is a 1-way. If both sides have sloped ramps but are asymmetrical, it is a 1.5-way differential.

A 1-way LSD is the quietest, with smooth, noise-free operation. The 2-way tends to be a little noisy, the cut of the gears and increased clutch pressure tend to “chirp” around corners. This is not tire chirp, rather the clutches slipping.

Saxton explained, “Gear tooth geometry directly impacts clutch system loading/compression (gear separation forces) but whether the clutches make noise or not is the result of clutch system design itself, lubricant used, etc. A properly designed clutch system doesn’t have to make noise – regardless of gear tooth type/geometry.”

When it comes to factory-style street performance, the clutch-type LSD, or Limited Slip Differential, has been the mainstay for back-street bruisers and boulevard cruisers for decades. This is Eaton’s clutch-type Posi, and it is very effective.

Where this is important is in the driving characteristics. If the LSD releases the coupling as soon as the throttle lifts, then it is a 1-way. This is the safest type of LSD, as it allows the rear tires to spin as needed.

If the differential increases the coupling regardless of forward or reverse torque upon throttle release, it is a 2-way diff.

This does two things:

• It allows the driver to be in control of the wheel spin, the differential is engaged, and in terms of drifting
• It keeps the wheels spinning throughout the drift

An inexperienced driver can find themselves in an unwanted spin with a 2-way LSD. There is a middle ground, the 1.5, which has less deceleration lock-up over the 2-way, but retains the coupling, unlike the 1-way.

There are two main types of LSD:

• Clutch
• Gear Driven

We spoke with Eaton’s test engineer, Jeff Saxton to get some details; he explained, “Both designs have been around for over 50 years and have evolved in terms of advanced materials for added strength & durability but the principles of operation remain essentially unchanged.”

Clutch-type differentials are what you commonly find in OEM applications. According to Saxton, “Clutch compression is achieved by the outward (axial) force of the side gears which then compress the clutches.” As the torque increases, the more compression is put on the clutches, coupling the axles, reducing slip.

“The Eaton Posi (a clutch plate type) is the original positraction differential providing efficient transfer of power to the rear wheels equally so that acceleration is maximized yet controlled,” Saxton told us.

This is how they work—as the spider gears climb each other as the side gears react with the spider gears, pressure is put on the clutches, which couple the axles together. Notice the symmetrical angles on the spider gears, this is a 2-way differential.

Clutch-type LSDs are popular. They are inexpensive and smooth on the street. With the different configurations (1, 1.5 and 2-way), there are enough options to allow you to get the right style for your application. Where the clutch-type LSD misses is in longevity. Since they require clutches, as time progresses, the clutch material wears away, requiring a rebuild. If left alone, the clutches with eventually wear away and there will be no coupling of the axles, although Saxton refutes, “This is not 100% the case and is entirely dependent on usage. Outside of heavy competition, an Eaton Posi commonly lasts as long as the owner wishes to keep it.”

Gear-driven LSDs are becoming more and more popular. Eaton’s TrueTrac was the first LSD to use helical gears over clutches, eliminating the consumable clutches and further reducing the noise of chattering clutches. Instead of controlling slip like a clutch/cone system, the gears are actually torque multipliers. As one wheel loses traction, the gears spin, transferring power to the wheel that is gripping.

Once a tire has completely lost traction, the LSD operates as if it is an open differential; the slipping tire receives no torque. In this situation, applying light pressure to the brakes (or e-brake) will put enough load on the axle to force torque application. This can be considered a drawback of the gear-drive, but not all gear LSDs have this issue. Some feature a bias plate that maintains a supply of torque to both wheels.

A geared LSD is well suited for drag racing, drifting and road racing. In street cars, ice can be a problem for the geared LSD due to the free-wheeling in no-traction situations. Saxton tells us “The Eaton Truetrac (a helical gear type) provides smooth power delivery in poor traction situations making it an excellent choice for hauling heavy payloads and trailering.

It is also an excellent front axle application choice for a vehicle that is both a daily driver and a regular off-roader.

For ultra-quiet and smooth operation, a gear-driven LSD is the best choice. Eaton’s True-Trac uses helical gears instead of clutches, so there absolutely no chatter. Geared LSDs actually work by multiplying torque, much like a torque convertor, rather than actually allow slippage.

Don’t Get Locked Out By Your Locking Differential

A locker does pretty much what it says, normally locking both axles together when torque is applied, ensuring both wheels spin regardless of traction. Where a limited slip diff changes how much torque is applied to each axle depending on traction, the locker sends the same power to both wheels all the time, under power. While that sounds like a spool, and it is very similar, the locker also has the ability to unlock.

When power output increases beyond the ability of an LSD, a full lock is needed. Strange Engineering offers their own version of the full-locker for racers using a Ford 9-inch rear. Built without using clutches, the new S-Trac is purely mechanical, designed to maximize traction and minimize wear and slippage.

There are two ways of achieving this- automatic and selectable. An automatic locker will open when the there is little to no torque applied to the differential. This happens in situations like cruising or low-speed cornering, where there is no power being applied.

As soon as you hit the gas though, for example, goosing the throttle out of a corner, the diff will lock. This can cause some unsettling handling issues, such as a sideways jerk as the locker engages. Lockers are streetable, they just take some getting used to.

“The Detroit Locker is the original differential of its type, dating all the way back to the 1940s. Over the decades it has been applied in heavy trucks, military vehicles, performance cars, street rods, NASCAR and all manner of off-road vehicles.

“This arguably makes it one of the most versatile traction modifying differentials ever invented. The primary reason for this popularity is its high torque carrying capability and resultant strength and durability.

“It has the resources and the engineering and historical expertise of the world’s largest manufacturer of high performance differentials behind it.  No one else can make that claim,” Saxton explained.

Lockers are known for being noisy and harsh on the street, which is why the LSD design is so popular for street rodders—they are quiet and easy. A locker is more efficient and simply will not slip off the line like an LSD can. The most famous of the lockers is the Detroit Locker from Eaton.

First introduced in 1941 as a OEM product and later for the aftermarket as the Detroit Locker, it is known for its strength and reliability. It is also the most versatile, having the most applications. For those that prefer a quieter differential, Eaton has the Soft Locker, which uses the same principle with different springs to reduce the clunking and jerking associated with engaging and disengaging.

For extreme budgets or for the builder who doesn’t want to mess with (or have the experience) the critical gear settings, the drop-in locker is a viable option. While not as strong as a full carrier, units such as this Lock-Right from Powertrax (Richmond Gear) work very well. They offer positive locking in the straight lines, but allow the inside wheel to spin when needed around a corner.

The harsh realities of a locker require the driver to either adapt their driving style or simply live with erratic handling. Manual transmission cars show the most abrupt changes, as torque is applied, released and applied again at every shift, so there will be more clunking and banging. As you accelerate out of a corner, the awkward handling rears its head.

The locker will free-wheel like an open diff until you hit the gas, applying torque, and the locker couples. This can cause oversteer or understeer, depending on the suspension, speed, and the road itself. These characteristics are even more pronounced in wet and snow/ice conditions. The vehicle itself also makes a difference; short-wheelbase and lightweight vehicles are more susceptible.

The best aspect of a locker is that you get true, fully-locked axles for maximum torque application just like a spool in the straight lines and free-spin action for the corners. In terms of strength and durability, a full replacement locker like the Detroit Locker is the best. These units replace the entire differential carrier, which means that you get beefy parts that are made to take the abuse of a race car.

Drop-in lockers, sometimes referred to as “lunchbox lockers”, are a little different. They perform the same task as a replacement carrier locker, but allow the user to simply replace the stock spider gears or limited slip clutches with a locker section. This means that you don’t have to mess with setting pinion depth or backlash on the gears, which can be intimidating for a novice.

This biggest drawback of running an automatic locker on the street is the noise and poor handling characteristics. To get around that, you could opt for an on-command locker, like the ELocker from Eaton. This style uses a simple electromagnetic field to lock the axles together when activated, but operates just like an open carrier when it’s is off, truly the best of both worlds.

Drop-ins are user friendly; they do not require any special set up and are compatible with C-clip axles. Installing a drop-in locker can as little as an hour or so. They are also cost effective. Adding this style of locker does not mean you need to invest in tools to set up a gears, it is a cheap way add traction to your stock rear end.

We asked Saxton about choosing a drop-in over a full replacement carrier and he told us, “This always comes down to strength considerations.  If the vehicle modifications include increased engine output, higher than factory ratios, large wheels and tires or other added mass (body armor), a full locker will in almost every situation offer a more durable set-up than a drop in.  Of course high strength axle shafts must also be considered with these types of modifications.”

Drop-ins function in a similar manner to a replacement locker, the locking action is based on torque application, so the handling characteristics are the same. When Richmond Gear introduced the Powertrax Lock-Right drop-in, they were quite noisy due to the design of the ratcheting action. Over the years, they have improved on their design, reducing the noise and chatter.

The biggest drawback of the drop-in is strength. While the locker itself is very durable, the overall strength can be hindered by the OEM carrier they are installed in. This makes them less reliable, but only because the stock carrier may fail, not because of the locker.

On-Command lockers offer the best of both a spool and an open carrier. An open carrier is the most street friendly design, there is no noise, chatter or clunking involved, but the classic “peg-leg” carrier is not good for drag racing. The locker’s sketchy handling can make them annoying on the street, but perfect for the strip.

The Detroit Locker is the original automatic locking differential. Over the years, more racers have used and abused the Detroit Locker than any other locking differential, and that is saying something.

To get both, you can go with on-command. This gives you an open carrier for street driven and at the push of a button or pull of a lever; you get a fully locked carrier just like a spool. With more function comes more labor on the install side and more cost. On-command lockers are typically air, cable, or electric solenoid operated, which means you need to run wires and hoses to the rear end.

The cost goes up with these units as there are more moving parts and functions that need to happen to make them work. On-command lockers are very popular with the 4×4 crowd, but they provide the best in terms of traction and drivability for a street-driven drag car.

Eaton has a new electronic locker, the ELocker. Originally developed for the H1 Hummer, this one is geared for the off-road but it may be just at home on the track. Where other on-command lockers require compressors and levers and such, the ELocker uses 12v power to activate the electro-magnetic field that forces the collars to move, locking the axles together.

So which is better, the LSD or the locker? In terms of straight line traction, the locker provides better coupling hands down, but going around corners will be noisy and unsettling. The LSD design is considerably quieter in the corners, and is easier to handle on the street. For a moderately powered street/strip car, the LSD is likely to be the best bet, but as power increases, so does the need for traction. So instead of firing up the ol’ MIG and welding those spiders, try swapping out that peg-leg for a real performance differential. Which one is up to you.

Installing short shifters in cars is something muscle car enthusiasts have been doing since the dawn of motoring time.  It is one of the simplest ways to get down the track faster by reducing the amount of travel between each gear’s gate.  But outside of being able to shift faster, they offer a sturdier feel and striking good looks.

Our 2011 Mustang project car “Wild E. Coyote” boasts 600 rwhp through its Vortech supercharged Coyote 5-liter and an updated suspension from Ford Racing, though the remainder of the drivetrain has been otherwise untouched.  We wanted to add some additional flare to Coyote’s relatively stock-looking interior while updating the problem-prone stock shifter assembly.

The main gripe in the 2011 Mustang’s shifter is the rear stabilizer that reinforces the shifter, plus the unneeded long throws.  We turned to a company that has been making shifters longer than anyone else, Hurst, for their new Billet/Plus 2 shifter.  It packs a whopping 27% throw reduction and improves upon the mighty 5.0’s drive-line, with a new billet aluminum base housing and a spherical pivot bearing. The higher durometer rear stabilizer bushing bolts into the stock bracket while reducing that sloppy shifter flex feel.

The Interchangeable upper stick will accept any Hurst stick with a two-bolt pattern or an addition stick is included that will retain the stock shift knob. A redesigned, spring loaded reverse lock-out improves factory “push down” lock-out detent design.

Installation

First start by removing the stock shift knob by simply unscrewing it counter-clockwise. Next, open the glove box so that you have access to the back portion of the center console. Carefully lift up the back so that all the console snaps release and then pull toward you. We disconnected all the wiring harnesses to ease the installation. Remove the three accessible bolts from the top and the fourth obstructed bolt from the bottom of the car, though we found that a ratchet-style wrench from the top worked too.

The rear shifter support will require a long (or a bunch of smaller) extensions to get around the driveshaft. With the two bolts out, simply pull the bushing backwards to release. The new bushing included with the kit is much stiffer than the stock counterpart and dramatically reduces flex under hard shifts with no additional noise.

There is a noticeable difference in build quality when comparing the stock shifter to Hurst's billet shifter. Once the pivot ball bushing cup is greased and transferred to the Hurst shifter, it is ready to go back in place with the new shifter base gasket. Also, the new rear shifter bushing will need to be greased once attached back to the factory bracket with zip ties.

Hurst gives you two choices in upper sticks - the black stick will allow you to reuse the stock shifter while the chrome version will work with the included Hurst shifter; of course we chose the Hurst stick and knob. Shifter noise is optional with the included rubber isolators that are placed between the shifter upper stick and assembly. Once the upper stick is assembled, make sure the new shifter works smoothly before installing the lower boot.

Included in the kit is a back up LED light that will illuminate when the vehicle is in reverse. This comes in handy since the shifter no longer has the 'push down and over' option and takes a little getting use to.

Not only does the Hurst shifter give you a better driving experience, it also looks a hell of a lot better than the factory shifter.

While the Hurst shifter added some much needed bling to our relatively stock-looking Mustang’s interior, it also added function.  The main gripe of the MT-82 transmission has been the sloppy shifter and Hurst completely eliminates that problem by giving you the ability to know that every time you shift you actually know it is in gear, and reducing the throw by 27% gets you there faster.  The stiffer rear bushing assembly further reduces that feeling of bending the shifter during hard shift.  With a street price of under $300 and an installation time of around two hours, this is possibly the easiest way to get down the track more consistently!

When making a lot of power, the rear suspension of a vehicle shouldn’t be a place to cheap out.  Not only do you need a suspension that is designed to plant (and not blow up) the engine’s power to the tires, you also need a tire with a wide enough foot print to transmit that power to the pavement.

Our 1965 Mustang project “Biting the Bullitt” recently had a complete TCI Engineering Custom IFS front suspension installed to make way for our Dart 427ci behemoth that pumps out over 1000 hp and 875 lb/ft of neck-snapping torque.  But not to worry, we have no intention on trying to put that much power through the stock 7.5-inch rear end!

It's rather simple when you look at it - our complete rear end setup for our '65 Mustang.

Much like the front suspension, the rear was going to need a complete overhaul if we wanted to make the Mustang hook.  Enlisting the help from Strange, Calvert, Wilwood, Autoworks, Mickey Thompson and Weld, we built a simple yet effective rear suspension that will handle all the power we can throw at it.

As any first generation Mustang owner knows, it’s damn near impossible to put a large enough tire in the stock wheel houses without diverting away from the stock leaf spring geometry, or doing some outter fender work.  Trying to keep this project as simple as possible, going to a link-type rear suspension was going to be out of the question.

But the suspension was only going to be half the battle in this war for traction.  The stock wheel houses in the Mustang are not very wide and have a very sharp bend, inhibiting a tall tire from fitting without the stance of a 1960s Gasser. We wanted to fit up to a 28×10.5-inch tire on the Mustang so mini tubs were a requirement for this project.

Autoworks Mini Tubs

The stock tubs have a very sharp taper and additional metal must be added to their width to do a 'poor man's' mini tub kit. The Autoworks tubs allow for better tire clearance and are built at the proper width.

Just getting the stock suspension out was a chore. The bolt and sleeve on the front mounts were ceased up so bad that we actually had to cut the old leaf springs, and then dissect the mount like a science project to get everything free. After we drilled out the spot welds that hold the trunk hinges onto the stock inner wheel houses, we busted out our Cornwell plasma cutter and sliced through the sheet metal like butter...and with minimal fires.

After a few trial fitments and some clean up, the Autoworks tubs fit snug as a bug. The inner sheet metal lines up with the factory stop, though we cut it out for more clearance. Having this flat sheet of metal on the frame rail really allows us to properly weld the tubs to the old outer houses. Installation isn't overly complex, it's really about slowly cutting back the inner houses to get to a point in which everything lines up perfectly. The trunk hinges will need to be cut down slightly due to the taller wheel houses and some sealer is a good idea to keep the trunk area dry.

Next, were the inherent limitations of the stock leaf spring placement.  We could do full tubs in the Mustang but without relocating the leaf springs, it was going to be a waste.  We initially started with a Money Maker Racing relocation kit that is pieced together from early Mopar parts, though after test fitting the kit on the car, we decided to only use half of the kit.

It comes with one inch offset shackles that are paired up to forward mounts with four through-floor studs. While the offset shackles worked perfectly, the forward spring mounts are recommended to be installed just inside the frame rail.  This would put the forward mount at a three inch offset in relation to the rear shackle.

Wanting to have a completely straight leaf spring, we opted for a new pair of forward weldable mounts that were moved in one inch from stock. They are much more durable than the stock two piece formed mounts.

Wanting to have a completely straight leaf spring, we opted for a new pair of forward weldable mounts that were moved in one inch from stock. This movement not only allowed us to safely clear a 275/60/15 or 28×10.5 tire, it also eliminated the two piece spot welded mount and replaced it with a thicker, single piece formed mount from AFCO.

Strange Custom 9-inch Rear End

With our rear spring debacle squared away, we moved onto building our Strange Engineering 9-inch rear end.  We opted to shorten the rear end with by one inch, which is the most we could remove to properly fit our Wilwood rear brake kit.

The rear end starts as their H1115 9-inch housing that is slotted for full tube engagement and has reinforced face plate for superb housing rigidity. The nodular iron case boasts chromemoly bearing caps retain by socket head cap screws that exceed aircraft grade 8 specifications as well as steel adjuster nuts. “The aluminum case is 20 pounds lighter, though we typically don’t recommend them on cars over 2600 pounds,” said J.C. Cascio of Strange.  “The reason is that with a heavier car, the case is more prone to deflect, and with that deflection the gear pattern shifts; that can lead to premature gear wear and failure.”  In case you didn’t know, Strange machined all of the SVO 9-inch cases for Ford during their production run.

The Strange rear end is all about strength and it will be the least of our worries when it comes to parts breakage on a high horsepower application like ours.

Filling the case is none other than a 35 spline Detroit Locker differential.  While most people would go with a spool when making this much horsepower, we stuck with the “Bitting the Bullitt” mantra and went with a differential for better street driveability.  The Eaton Detroit Locker is designed to deliver 100% of the torque to both drive wheels while still allowing wheel speed differentiation to maximize traction between the wheels and around the corners.

Mated to the Detroit Locker is a Motive Gear 3.70:1 ring and pinion set.  The front of the case is sealed off with a Daytona style taper bearing support that features a larger than stock rear pinion bearing. Due to the oil porting this support provides the best solution for street/strip users who are seeking an increase in strength over stock pinion supports. “It has the same oiling capacity as the cast iron pieces we sell, but the forged aluminum body is more rigid, and will give you less deflection at the pinion bearing,” said Cascio.

Strange's S Series axles are designed for a street car because they have the ability to flex, unlike their Pro Series axles that are completely hardened.

Strange Engineering Custom 9-inch Street/Strip Rear End

• H1115 9-inch housing with tubes and big Ford housing ends
• 35 Spline Detroit Locker differential
• 3.70:1 gear ratio
• S Series 35 spline axles
• Nodular iron case
• Upgraded Daytona style billet pinion support

Calvert Suspension Components

If you are a leaf spring drag racer and you have never heard of Calvert Racing, then you have been living a sheltered life.  They are renowned for building everything from traction bars to leaf springs and we had to get, well…all of it.  Virtually everything Calvert makes, we have equipped on the rear end of our ’65 Mustang project.

It starts with Calvert’s HD spring perches that we purposely left off during the rear end manufacturing process so we could properly locate them on our adjusted spring location. While a spring perch doesn’t seem to be a complex piece, it does come tabbed for optimal welding penetration, gusseted for added strength, and extends to the center of the axle tube for added contact surface.

The spring perches were purposely left off during the rear end manufacturing process so we could properly locate them to our adjusted spring location. The Calvert HD mounts cover 50% of the axle tubes for the highest strength possible.

Multi-leafs are designed to give progressive dampening when driving and while this is fine and dandy for a daily driver or road course racer, going to a single rate split mono leaf was going to be much more desirable from a weight savings perspective.  Also with a split mono leaf one can expect more repeatable launches pass after pass. Calvert offers these springs in 220-225 pounds and a variety of heights.

Calvert’s most well-known product by far are their CalTracs traction bars. Think about the dynamics of a leaf spring; as the tires try to grab for traction, the leaf springs begin to curl upwards in an S-shape, lifting the axle off the ground and instantly causing traction problems. The tire turns into a basketball and that dreaded feel of wheel hop leaves the rear suspension and driveshaft begging for mercy.

Calvert's CalTrac bars keep the leaf springs from coiling during launch, which can lead to a dramatic traction loss. The split mono leaf shocks weigh nearly half that of a traditional multi-leaf.

Tech Tip:

On foot-brake cars you will want to start with a stiffer rear shock setting, while trans-brake cars prefer softer settings.

The CalTracs are simple in design but work to keep the spring from wrapping under hard acceleration.  It replaces the lower shock mount, connecting with a threaded piece of tubing that finally mounts to the lower leaf spring mounts.  Not only does this triangulate the leaf spring to reduce wrap, but as the leaf spring begins to move upward, the forward mounting brackets also limit the leaf spring upward movement.  Adjusting the threaded pipe effects the pre-load of the spring.  John Calvert of Calvert Racing recommends, “What we first recommend is putting the forward heim joint in the hole that puts the bar most level at ride height. Next, put a quarter turn of pre-load (extending the bar length) on both sides.  You should run it that way for the first couple track sessions. After the first session though, we would verify that pre-load was still set properly after initial break in.”

Calvert continued, “The real goal is develop a baseline for tire pressure, starting line RPM, and shock settings that the car is most comfortable with before adjusting the CalTracs any further. For radial cars, even an eighth to quarter inch of air gap can be ideal because it allows the rear end to rotate slightly before engaging the CalTracs.  We like to recommend even a few back-to-back passes experimenting with air gap versus pre-load to see what the car likes the best.  What you want to do is hit the tires as hard as you can without spinning and sometimes adjusting from pre-load to an air gap setup will help slow that cycle on bad tracks.”

Calvert's adjustable shocks are offered in a wide range of bolt on applications and feature an eight way adjustment dial that effects the shock's rebound.

Rounding out the suspension is Calvert’s CR Series nine-way adjustable shocks. The adjustment for these shocks are primarily designed to control rebound after launch to control rear body separation.  Calvert continued his setup techniques by explaining, “Shock adjustment mainly depends on if it’s a foot-brake car or a trans-brake car.  On a trans-brake car we recommend to run the shocks very loose while a foot-brake car should be ran tight. If separation between the tire and the fender happen at a really fast rate, there can be instances where all four tires will come off the ground; this is an instance where you want to slow the separation by tightening up the shocks.”

Calvert CalTracs PN# 6400

• Complete bolt-on – no cutting, welding needed
• Keeps axle from rotating, helping maintain pinion angle
• Eliminates spring wrap-up
• Full pre-load adjustability

Calvert CR Series 9 Way Adjustable Rear Shocks PN# CR44116

• 9 way externally adjustable knob
• Dial primarily adjusts rebound, enabling driver to control excessive body separation
• Heavy duty industrial steel bodied design

Calvert Split Mono Leaf PN# 2000

• Complete with aluminum bushings in front eyes and urethane bushings in rear eyes
• Split mono leafs made to work in conjunction with CalTracs
• 200 – 225 pound spring rates available
• Substantially lighter than multi leaf springs for unsprung weight savings

Wilwood’s Four Piston 12-Inch Rear Brake Kit

When going 140+ mph down the quarter mile, you really need a set of brakes that will stop you before the run off ends. Nothing gets the pucker factor fired up faster than running out of brakes before a safe turn off.  While many hardcore race cars go with a lightweight plate-style rotor to reduce rotating weight, we went with a traditional Wilwood vented rotor that has been cross drilled and slotted.

In addition to the aesthetic appeal, the venting and cleaning action of the hole and slot pattern helps to reduce pad glaze and minimize irregular pad build-up on the rotor faces. The results are a smoother engagement feel at the pedal and consistent response from the pads.Again, we want to enjoy driving the Mustang around the street and we are willing to Bite the Bullitt by carrying the additional weight.

Bolting to the 12 inch rotors (the biggest Wilwood rotor we can fit behind our Weld wheels) is a Dynalite four piston caliper. These calipers are super light; only weighing 2.8 pounds each and are stress-flow forged. The process of stress-flow forging re-aligns the metal’s grain structure within the contour of the caliper body. This process eliminates the breaks and interruptions to the internal grain structure that occur when machining a straight block billet.

This rear kit actually carries the exact same specifications as our front brake kit.  When it comes to proportioning the kit, Wilwood’s Michael Hamrick suggests, “You want to put the proportioning valve on the set of wheels that are going to lock up under hard braking. In a drag racing application, you have plenty of tire out back and not enough on the front, which will lead you to wanting more rear brake bias.”

Included in the kit is Wilwood’s parking brake assembly with integrated billet caliper mounts.

Wilwood Dynalite Rear Parking Brake Kit PN# 140-7140-D

• Black Electro Coat drilled, slotted, and vented 12.19-inch Rotors
• Forged billet 4-piston calipers
• High performance Wilwood brake pads
• Parking brake assembly with integrated billet caliper brakes

The axle must be removed so that the parking brake assembly can be installed. After that, the axle is slid in place, the bearing retaining plate then slides in place and is secured with the included bolts through the axle's access hole.

The calipers slide in place and are retained by two bolts. The pads slide in place and are secured by an easy to remove cotter pin.

Capped off with Weld Wheels and Mickey Thompson Tires

Capping everything off is a set of Weld Classic RT wheels wrapped in Mickey Thompson rubber. Weld’s RT wheels are a multi-piece design for the maximum strength with the lightest weight possible. Also the wheels easily clear our 12-inch Wilwood rotors, though Weld also touts these wheels for F-Body, S197 Mustang GT, & other late model performance applications for their brake clearance capabilities.  Weld’s RT wheels surpass all applicable race wheel & SAE street wheel standards and carry a maximum load rating for street applications is 1200 pounds per wheel with a 28-inch tire.

While the $199 paint job is toast on our Mustang now, she will be getting a full make over after we get a few passes on it so she can look as good as the wheels.

The wheels are available with a black anodized or polished center and are designed for use with a 5/8-inch drive stud or short shank mag style lug. In the rear we went with a 15×9 width and a 5.5 backspace that is accompanied by a half inch spacer to give proper clearance to the leaf spring. Mickey Thompson supplied a set of their proven 275/60/15 street radials plus a pair of 26×4.5×15 front runners. Both tires are radials and do not require tubes.

Our Project “Biting the Bullitt” ’65 Mustang has come a long way in recent months with the completion of the TCI front suspension and most recently the rear.  Combining the simple yet sturdy design of the Mustang’s leaf spring rear suspension with modern technology will help us be as consistent as possible off the line.  For Strange’s 9-inch and Wilwood’s brakes, having a bullet proof means to transmit and also slow down all the power we will be making is insurance we can look forward to on and off the strip!

Photo Gallery

In the fabulous sixties, having a robust transmission meant having four speeds. The box itself is limited in size, and strong gears had to be big gears. Improvements in metallurgy and power takeup (clutches, especially) have made five-speed transmissions popular for the past thirty or so years, as design and material improvements allowed stronger transmissions that could fit in sporty-sized cars.

Still, everyone learned, as they improved engine performance, that a torquey engine would turn gears into little more than lumpy pulleys and force the shafts apart, and ruin bearings and housings along the way. To put more power through a transmission, the case needed to be stronger; the gears needed to be stronger; the shafts needed to be stronger; and the fluid technology had to give everything just the right amount of “slick.”

Not So Long Ago

The TKO is really the trans behind Tremec's aftermarket success. The Magnum is essentially all the best flexibility features of the TKO, combined with the spectacular refinement and torque carrying capabilities of the TR-6060.

Designers learned that the side-loading transmissions so loved by GM had some inherent weaknesses, not problematic when they were bolted to the relatively anemic engines of the day, but obvious when hot-rodders got to work; Ford’s top-loader was an improvement. Then GM built the Muncie M-22 “Rock Crusher,” Chrysler introduced its big HEMI 18-spline A-833, and the race was officially on.

Aluminum cases, with intricate ribbing, can now be stronger than the old cast iron; internally, steels are better-developed; inspection, manufacturing consistency, lubrication – progress on every front. Sometimes, though, you just need it to be bigger. The Tremec’s T-56 Magnum has all the improvements. And yes, in some dimensions, it’s bigger. So now, we can have six speeds, and allow our better engines to use more of their improvements doing what they like to do: pushing pavement behind us.

Borg-Warner developed the end-loading six-speed T-56 two decades ago, for its first use in the 1992 Firebird. It found its way into other GM products including the Corvette; then it proliferated further. Tremec, building transmissions since 1964, makes gearboxes for some of the most sought-after road vehicles, for heavy equipment that produces 2400 ft-lb of torque, and for some military vehicles. They build some 300,000 transmissions each year. Eventually, Tremec bought Borg-Warner’s light-duty operations. Today, the T-56 lineage remains in production as the fully-redesigned six-speed TR6060, first used in the Shelby GT500 at its debut a few years ago.

Tremec supplies the S197 Magnum gearbox for 2005-and-up Mustangs as well as the TR-6060 from the GT500 Mustang. Note the unusual 'semi-remote' shifter arrangement on the 6060, as well as the long extension housing on the S197 Magnum designed to take its place. One other special point of interest is the crossmember and SFI-approved steel bellhousing that comes with the S197 Magnum. Previously Tremec never offered these items, but due to the expected demand Tremec provided these pieces to make the swap simpler and more cost effective. End users will still need to acquire a 26-spline clutch and appropriate driveshaft to make the full conversion (will be available through Tremec Elite Distributors).

All In The Family

Getting Your Hands On One

The Tremec TR6060 is used in all Corvettes, Cadillac CTS-V; the Viper and RT and SRT Challengers; all GT-500s, including the SuperSnake; and all new Camaro SS and ZL-1. Still, if you were to pirate one of these from a junkyard, you’d face myriad problems.

Tremec’s Marketing Director Nate Tovey notes that the 6060 shares no parts with the old T56, though it looks like a mild rework – until you really look. “It looks similar. It has the same DNA, if you will — but everything has been redeveloped, a direct result of demands from the [car manufacturers] for handling greater and greater power.”

In its aftermarket configuration, this transmission is now known as the T-56 Magnum, or simply “Magnum.” It looks similar, but don’t even think about it: it’s not possible to change out parts from an old T-56 to make “your own Magnum.”

The 6-speed offers great advantages. Tovey continued, “Not just fuel economy from the overdrive, but it will be quieter; you’ll have lower shift efforts; it will be less fatiguing for you and your whole drivetrain. And having a couple extra gears, you never have to be in the wrong gear when you’re joining interstate traffic.”

The Magnum is a 6-speed box, with triple-cone synchronizers for the first four speeds and double-cone synchros on the overdrives and (constant-mesh) reverse. They feature robust and standardized 26-spline input and 31-spline output shafts. To make retrofits easier, they have electric and mechanical speedometer hookups; mechanical or hydraulic clutch linkage will work.

The T-56 Magnum will be available in configurations for 4.6 and 5.0L Fords, LS1 GM applications, as well as for the conventional small-block Chevy. Custom bell housings will be available through most Tremec distributors for other applications.

The T-56 Magnum features 6-fully synchronized forward gears as well as a synchronized reverse. All T-56 Magnums feature a rigid die-cast aluminum ‘short throw’ shifter that offers tremendous strength with smooth, positive shift action. It also features the same ‘reversible’ function as the wildly-popular Tremec TKO 5-speed shifter for added versatility with respect to shifter location. Stealing another page from the TKO, Tremec also designed the Magnum to include both electronic and mechanical speedo pickups.

It’s a Matter Of Ratios

The Magnum has several internal ratio sets available. Tremec has a lot of help available on its website, plus a detailed online Applications Engineering form, that will help you match your needs to their models; and both Tremec and several of the distributors maintain help lines; some are manned 24/7.

Specifically regarding ratios, fourth gear is direct-drive (1.00:1) in all the Magnums; fifth and sixth are each overdrives, with three ratios available, all the way to 0.5:1 – so sixth gear can be twice as tall as fourth, for thumping down the highway, and the space between fifth and sixth is much easier to bridge than with just a five-speed box, where the leap to overdrive could be radical, and annoying.

T-56 is a family, though, you can’t swap one T-56 for another and expect everything to work, or even to fit. You can’t expect to bolt the new Magnum in, either; that’s where the Tremec distributors come in; all of them know their stuff.

Tovey says, “Having that sixth speed, rather than a 4-speed with an overdrive that’s got a giant step, is a big advantage. With a five-speed, you can get a .82 or .64 overdrive – with a 6-speed, you can have both; and there are .74/.5 options.”

The model numbers for the Magnum configurations specify the ratios, to deliver a range of wide-ratio or close-ratio solutions for various engines. Note, for instance, that if you order the lower first/second pair of gears, you automatically get the higher fifth/sixth. If you purchase a 2.66 first-gear ratio version, you get the lower overdrive ratios (.82, .64); if you get the 2.97, you get the higher (.74, .50). But a Tremec distributor can change the overdrive ratios – and yes, you’ll need to change them both – if you think you need your box set up that way.

Adapt To Survive

Since adaptability is another attribute of the Magnum (strength and smooth operation being others), it bolts to many aftermarket bellhousings, and also to many stock GM bellhousings; a reverse-lockout solenoid is standard.

A shifter comes on the transmission, and you can have it work from any of three positions on the box’s centerline. The rear-shifter is supplied standard, and it’s reversible to provide two popular positions: you can mount it with the stick at the front or rear of the cover. The farther-forward “mid-shifter” option is also available. And distributors have offset shifters, to move the stick position left or right as far as two inches.

A stand-alone view of the gears (top right) shows the substantially increased face width of those used in the new Magnum (left) as well as a fantastic look at some of Tremec’s new manufacturing processes at work. Rather than forging the gears and clutching teeth all as one unit, as was done in the past, Tremec now laser welds together the two separate pieces. This allows for a much more intricate design of the clutching teeth, including a finer pitch on the teeth themselves as well as machined-in positive stops. The process provides a noticeable improvement in shift feel and makes ‘overthrows’ a virtual impossibility. Also note the larger bore of the gear to accommodate the heavier-duty mainshaft of the T-56 Magnum.

The images illustrate the new and improved shift forks of the T-56 Magnum (positioned in rear). Note the substantial amount of added cross-sectional material for increased strength as well as the new integrated shift links. This feature is important because the links now have their own separate provisions for placement rather than loosely fitting into a keyway shared with the rail bore. What this does is promote a more precise shift feel along with helping to virtually eliminate deflection of the fork itself.

Installation Tip:

Always check shift handle length. Some will sit too high or too low. Get the handle last, after the seats are installed.

Though the Magnum is rated for 700 ft-lbs of torque, Tovey says “Don’t really think in terms of ‘numbers.’ If you know how to treat your transmissions, these will support far greater torque than they are rated for.” He adds, though, that abuse is just dumb. “Think of the shock loads you put on the drivetrain with, say, clutchless shifting. Besides, when you do that, the synchros will wear out. ”

The similar-looking T-56 box has been around for decades, in various configurations. T-56 is a family, though, not a specific transmission; you can’t swap one T-56 for another, and expect everything to work, or even to fit. You can’t expect to bolt the new Magnum in, either; that’s where the Tremec distributors come in. Tremec distributors have their particular specialties – drag, road race, pro street, etc.; all of them know their stuff.

The maintenance manual is available online, too, explaining useful things like how you shouldn’t tow with the drive wheels on the pavement and the driveshaft connected. (Disregard this advice and you’ll make the parts blue inside, and everybody knows that blue gears aren’t good.)

At Tremec, one could see the whole manufacturing process, from the raw bar stock coming in the door, through forging, into machining, assembly, inspection, and test – and into the box. That allows Tremec to control the entire process, and it results in consistent quality.

The precision gearbox appreciates precision in installation and mounting. Tovey says, “The best thing you can do is to pay attention to details: get your bellhousing dial-indicated and properly mated; your driveshaft angles must be in-spec. Poor setup can be expensive.”

In this image you can see the only feature deleted from the T-56 with the advent of the Magnum—the 10-spline input shaft. While it’s not unheard of for enthusiasts to jam big power through a 10-spline setup (they’re especially common in late-model Ford circles), Tremec engineers decided to remove any potential weak points before rating the Magnum for 700 ft. lb. street/strip duty. Saving space for strength: that’s what the Magnum’s new synchronizer design is all about. The physically narrower design is what allowed Tremec to equip the Magnum with wider gears as well as add some extra meat to the front and rear of the main case. These new synchronizers feature increased capacity over their predecessors and utilize a new support system with individually spring-loaded ball type inserts. A vast improvement over the old hoop-style strut, these new inserts control loads with far greater precision. The compact design also translates to shorter throws and a smooth, over-center feel for the driver.

This exploded view of the Magnum’s new synchronizers is beneficial in understanding some of the truly state-of-the-art technology at work. A lot has to happen in a very short time (see milliseconds) to make those high rpm shifts go quick and feel right. Making matters feel even better, the T-56 Magnum comes with triple cone synchronizers for the 1-2 and 3-4 shifts, and double cones for the 5-6 and reverse gears.

Coming Through In a Clutch

Clutches are the other main causes of end-user frustration and dissatisfaction. Tovey stated, “An overly-aggressive clutch can make a big difference in drivetrain life. When you get into ‘racing,’ you’re losing drivability. The few milliseconds you’d gain shifting a full-race transmission will not be noticed anywhere but the track. But the drivability of a race transmission will ruin your enjoyment in just a few hours. Recently, clutch manufacturers have come up with dual-disk clutches; these, too may be a viable option.” Though Tremec does not endorse clutch products, you can get a lot of good advice from Tremec distributors in clutch selection.

Tremec recommends mineral-based, conventional transmission fluid. “Ideally, we like Dexron III, though it’s becoming hard to get. Any Dexron should do well. Emphatically, we advise to stay away from synthetics. For extreme applications, you may need something different, but don’t deviate from our recommendations if you want to have a warranty.”

Here’s why: some synthetics (and Tremec hasn’t tested them all) actually erode the lining of the synchro materials. Using the wrong fluid can kill a transmission without your ever abusing it. For the old-timers, he notes that old-fashioned gear oil impedes the action of the synchronizers. When the cone presses on to the gear, the thick fluid will cause a slow, clumsy shift. A hypoid gear oil works likewise: the synchros require some friction, and these oils get in the way of proper mating, as they are designed to do!

Tremec’s new T-56 Magnum is the long-awaited replacement for the T-56 and aftermarket equivalent to the TR-6060 that currently serves as factory equipment in many Vipers, 'Vettes, GT500s, Challengers, Camaros, CTS-Vs, and G8 GXPs. For a price tag of about three grand, it’s a worthwhile investment for anybody seeking the performance and practicality of six forward gears along with massive amounts of torque capacity.

Clearly evident is the increased bulk of the Magnum’s input shaft, a good idea considering it’s the transmission’s first line of defense for major power handling.

The Tremec Team

Tremec’s distributors are the best outlets, and each offers expert technical advice. Find the distributor that most-closely serves your application, and listen to what they say. Distributors will help with bellhousing selection, speedometer hookups, chassis mounting, slip yokes, driveshafts, clutch recommendations and linkages – everything you’ll need. Many offer “kitted” transmissions, with the parts you’ll need to complete your particular installation.

The torque rating goes from 450 ft-lbs to 700; the triple-cone synchros last a long time and make shifting sweet; vibration and noise are reduced; the convenience of being able to use either electric or mechanical speedometer hookups, of a bellhousing selection, of standard 26/31-spline input and output, and the adaptability of three shift lever positions can’t be missed.

The Magnum is currently offered for GM LS and Ford Modular applications; Mopar is on the way. The difference is at the front of the transmission. Distributors will get you into the right bellhousing and adapters.

Tovey wrapped it up: “People don’t pay a lot of attention to their transmissions until they make noise or pop out of gear. Based on the TR6060, this is by far the most refined aftermarket transmission ever released. Quiet, durable, easy-shifting, short-throw – all these have gone through the same kind of testing the OEMs use. It’s not just about power-handling. It’s about flexibility and refinement. In the aftermarket, you won’t find anything else that will give you the options you need, especially for the shifter location.

“The Magnum is the top product in this market. This is not a ‘race’ transmission, until it is prepped or modified by our distributors. We are producing the ultimate street car transmissions, bridging the gap between civility and handling massive torque. The Magnum is a livable six-speed that is strong enough to do weekend warrior and occasional Sportsman events.”

Does your Powerglide get heat-soaked in the pits and staging lanes between runs? Do consistent transmission and converter temperatures sound like a good idea for your bracket racer? Then the ATI SCS-30 cooling system may be just the thing. Designed by ATI Performance president Jim Beattie, the SCS-30 is a standalone cooling system that pumps all that hot ATF through the transmission and cooler, instead of letting it just sit in the case.

In between rounds, the transmission can heat soak because the hot fluid sits stagnant in the case heating all those parts up, much like how the engine temperature will rise after being shut off. For a street car this is not that big of a deal, but when consistency means winning or losing, it is important. Similar to your engine’s cooling system, the fluid functions as the coolant for the transmission; however, where the engine coolant is just a coolant, transmission fluid also provides the hydraulic action for the basic function of the transmission. Furthermore, it is the sole lubrication method.

There are a lot of moving parts inside a transmission and heat is the enemy. ATI’s SCS-30 can help protect your Powerglide.

The transmission often gets overlooked in terms of cooling and lubrication. Having spent a lifetime developing high-performance transmission products, Jim Beattie designed the SCS-30 for the Powerglide to bring consistent temperatures to the mix. “The turbo cars in particular were creating steel bluing heat in the converters, and the super-hot oil was sitting in the converter until they got back to the pits and started a fan blowing on it,” Beattie told us. “We actually could see the fluid level heat stains inside the converter from the hot oil laying in there after a run, and found that it was important to start the cooling process immediately following the run.” This led to the development of the SCS-30.

The Different Options

There are multiple options for the SCS-30, including the dragster version that features the cooler mounted at the top of the case. There are three main versions of the system; factory installed ($695), Tranny Builder package ($1589), and the Dragster package ($1988). The Tranny Builder pack comes with the cooler system, SuperCase, Chevy bellhousing and an OEM extension housing. The Dragster kit includes the SCS-30, SuperCase, cooler and fan, case mount, handles and hoses. Other options include ATI valve bodies with either a transbrake or foot brake, temperature controller and a 12v fan-mount cooler. The SCS-30 is available as a factory installed option for new ATI Powerglide Transmissions and SuperCases, but if you already have a built ‘glide in an ATI SuperCase, the cooler can be retrofitted to your case.

Powered by a heavy-duty 30 GPH pump, the 12v motor mounts to the exterior of the case and uses a 10-mm belt to drive the internal pump.

How it All Works

When the engine is off, the cooler pump kicks in, pumping the trans fluid into the converter, out to the cooler, and back into the transmission at 30 GPH. This requires either an electric fan on the cooler or an ice cooler to provide the heat exchange. The external pump for the cooling system does not replace the function of the internal transmission pump; this is not a high-pressure pump, rather a simple high-volume pump to keep the fluid moving. When used with the optional temperature sensor and a bung heater, the system can be tuned to maintain a specific temperature. Transmissions work best in a specific temperature range, so being able to manage the temperature variation is critical.

Another interesting aspect of the SCS-30 is that the pump maintains the lubrication function of the fluid. When the engine is shut off after a run, the transmission stops pumping fluid, but the internal parts are still moving. With the SCS-30 engaged, the fluid continues to lubricate the transmission, reducing wear and tear on critical parts. This means more runs between rebuilds, saving time and money over the course of a season.

Inside the case, you can see the actual pump (lower right), the stainless braided lines and the modified valve body. You can modify your valve body to accept the lines or use an ATI modified unit.

The SCS-30 cooling system is a serious race piece, designed with a heavy duty, extreme-temperature, all-metal geared pump. A 10mm timing belt runs the HTD toothed pulleys on the exterior of the transmission case. Inside, the Teflon lined, stainless braided lines use AN fittings that attach the internal pump housing to the valve body. The pump runs through the filter, so there are no worries about sucking junk into the inner workings; just good, clean ATF. The exterior lines (Dragster Package) also feature AN fittings, with nylon braided rubber lines for durability. The system requires either the ATI valve body kit or you can drill and tap your existing valve body. All of the electronics are 12-volt.

The SCS-30 should be considered for any serious heads-up or bracket racer that wants consistent transmission performance. This system eliminates the fans and sprayers that are currently being used. That mess is inefficient; the SCS-30 works much better, with just the flick of a switch. As time permits, ATI is looking at developing similar cooling systems for other transmission platforms as well. So now you can stop blowing up transmissions and losing races because of an inconsistent slushbox.

Team Z Motorsports, based in Taylor, Michigan just outside of the Detroit and Dearborn auto manufacturing hub, has become one of drag racings most renowned and respected chassis shops and component manufacturers, with a strict attention to detail that rivals anyone else in the business. Company founder Dave Zimmerman has maintained a solid focus on the suspension side of things with a complete line of suspension and chassis components to compliment their full-on car buildups. And thus, in order to get the most out of our Fox body, who better to not only pick the brain of but put our newfound knowledge to practice with than Zimmerman and company.

The 9-inch housing that we've received for our Fox body is based upon Team Z's standard 9-inch housing, but features the added upper and lower control arm mounting points featured on their higher-end Outlaw housing.

Team Z recently supplied us one of their trick 9-inch rear end housings that’s based upon Team Z’s standard Mustang Bolt-in Ford 9″ housing but features the adjustable upper and lower control arm mounts found on their upgraded Outlaw Stock Suspension Bolt-in 9″ housing. In this article, we’ll show you everything you need to know about the Team Z housing, along with outfitting our rear with a set of 35-spline Strange race axles and a 35-spline spool.

This trick Team Z 9-inch sports axle tubes constructed from 3", .188" wall thickness 4130 chromoly tubing for superior durability.

9-Inch Fox Basics

“The 8.8 housings are kind of fragile: they won’t handle 800 to 1,000 horsepower reliably, and so a lot of people are shying away from the 8.8′s,” said Zimmerman. “But the cost of the nine-inch is typically outrageous, and so with this housing, we targeted the in-between market there: somebody that doesn’t want to spend the money on an Outlaw fabricated 9″ housing, that wants the lighter weight of the 8.8 and the reliability of the nine. That’s what we’re going after.”

The housings’ center section is fabricated through a process known as hot stamping, where the metal is heated up until its cherry red and then stamped into shape. In using this method, the material becomes so strong that according to Zimmerman, one would be hard pressed to even cut on it. This process is one that many OEM manufacturers are using these days on their hydroforming materials. The axle tubes are constructed from 3″, .188″ wall thickness 4130 chromoly tubing.

While the longevity and reliability of this 9″ housing is certainly one of its strongest (no pun intended) attributes, what the suspension wizards at Team Z have focused most on and what they believe sets this particular housing apart from its competitors is its geometry. And it’s this geometry that will benefit us in wringing the most out of our Fox body Mustang.

Zimmerman's 9-inch creation sports multiple pickup points top and bottom for making ample adjustments to your vehicles instant center.

Fox Body 9-Inch Geometry

“The geometry on the upper control arms in our new housing is ideal,” explained Zimmerman.”We have multiple pickup points on the top, and most 9-inch housings out there don’t have the correct pickup points. With the multiple pickup point options, you can raise or lower the car, and while no one would ever raise it, if you lower the car, you have the ability to adjust the upper control arms. And the same goes for the lower control arms as well – we have four pickup points on the lowers for adjustability.”

“On many aftermarket 9-inch housings, as you begin to lower the car and the upper control arms are in the location that they end up on a 9″, what most often becomes the case is a very short instant center in the car,” explained Zimmerman. “That tends to cause a car to hook well in the first 20 to 30 feet of the racetrack, but once the power begins to come in, it’ll unload the chassis due to the both the short instant center and the high anti-squat value.”

The instant center of a suspension system is the point in space upon which the suspension links  – in this case the control arms – meet.

Because the motiion of the wheel and tires are restricted by the links of the upper and lower control arms, the motion of the wheel and tire forms an imaginary arc in space with an "instant center" of rotation at any point along its path.

To get a better idea of what instant center looks like, grab a pen and a napkin and first draw the rear wheel and the center point of the axle. Then draw a line from where the lower control arm mounting point on the housing is to the mounting point of the lower control arm on the chassis. Finally, draw a line right down the center of the rear end housing to the front of the car. With those drawn, locate the point at which these two lines intersect, and you’ve found your instant center. Obviously finding the instant center of your actual car is going to require more than a pen and a napkin, but you get the idea.

The further back and higher in the car that this intersection point is, the faster the rear tires will plant to the pavement. The tradeoff is that the tires also unload quicker. Thus, a fine line in discovering the happy medium between these two action exists in setting up the control arms on your car in order to get the tires planted and keep them planted. The Team Z Fox 9-inch housing allows you to optimize this geometry whether you’re running 10′s or 7′s.

The further back and higher in the car that the instant center "intersection" point is, the faster the rear tires will plant to the pavement. The tradeoff is that the tires also unload quicker.

The anti-squat value mentioned previously is an element related to instant center and is designed into a rear suspension link setup to combat a cars natural tendency to squat under acceleration. By strategically placing the instant center at a certain height in relation to the cars’ center of gravity, you can control just how much the car squats or lifts. The higher in the car that the instant center is located, the higher anti-squat value, and the lower it is the less it has. Because weight transfer in drag racing is critical, finding that fine balance between lift and squat is crucial when setting up the car. Generally, a very high instant center will tend to lift the car and affect traction in the front part of the track.

As mentioned previously, the multiple lower control arm mounting points on the Team Z housing makes it possible to move and lengthen the instant center to achieve what Zimmerman calls a “more efficient instant center.” In our Mustang, the ability to adjust the instant center will not only improve our short times on the dragstrip, but also effect how the car handles down track. “It definitely makes the car more stable going down the track with the correct instant center in it,” Zimmerman explained.

“If you drop the ride height, and mini-tub the car, and have it slammed to the ground, at that point, the lower control arm becomes more critical because you don’t want the lower control arm pointing down in the front. This will lower your instant center and basically just ruin your traction.” “We’ve built plenty of cars and I can’t even count the number of stock suspension cars that I’ve set up. I’ve got a window that I like to work within, and with the pickup points on this housing, one will be able to achieve a very good instant center for just about any ride height of car.”

Getting Strange: 9-Inch Axles And Spool

In order to get our new Team Z housing suited up and ready for installation into our Fox, we’ve got some other essentials it’s going to need for proper working order: namely, a set of axles and a spool.

For the center section, we’ll be using a 9-inch Ford nodular piece, mated with a new 9-inch Ford Pro race 35-spline spool from Strange Engineering and 3.89 gears from Motive Gear. The new spool is of chromoly forging construction, making it “one of the lightest spools on the market,” according to Strange’s JC Cascio. This particular spool weights in at just 8.2 pounds. These race-intended spools allow for the use of larger axle splines, and it’s lighter and stronger design improves ring and pinion life by providing for a more rigid gear mounting.

The new components going into our rear end buildup, including 35-spline axles and spool from Strange Engineering, a 9-inch Ford nodular center section, and large rotor Wilwood disc brakes.

Also from Strange, we’ve installed their Thru-Hardened Hy-Tuf 35-spline Pro Race axles. These axles are made from an ultra-strength alloy steel forging, which was actually developed for highly stressed landing gear in military aircraft.The combination of Hy-Tuf and thru-hardened heat treament not only equips these axles with superior torsional strength, but is also very lightweight – perfect for the drag racing applications for which they’re designed.

The specific axles that we’ll be using measure 30-inches for the left and 27 on the right, with 1/2-inch wheel studs, ball bearings, and the works. Both the axles and the spool are available from Strange as part of a 33 and 35-spline package (Part # P2007).

While our Fox body is a nine-second car, and would hold up well with a 33-spline setup, we opted to go the 35-spline route not only for added peace of mind, but for future-proofing, as well.

“Based on the weight, horsepower, and application of the car, 33-spline axles probably would’ve been fine, but by going with the 35-splines off the bat, there’s more strength there for upgrades down the road should a power adder come into play,” explains Cascio.

Dave Zimmerman and his Team Z posse are intently focused on the suspension side of things, perhaps more than any other house of speed in the Mustang market. And this new housing resting under our Fox body puts on prominent display the results of the homework they’ve done and the expertise that they’ve acquired, leaving little doubt that our Mustang will hook with the best of them.

We think transmissions don’t get the proper credit they deserve. While everybody wants to talk about how many cubic inches, carburetors or how much horsepower your ride’s engine cranks out, very few people bother to ask, “What stall converter you running?” or “How many discs does that clutch have?” Nope; like the Jan Brady of powertrain parts, the transmission will always – and unfairly – live in the shadow of its sexier sibling.

Since Oldsmobile introduced the Hydra-Matic in 1938, the first American-made clutchless hydraulically-operated transmission (a factory option available for a whopping $57!), Americans have been warming up to the automatic transmission faster than anywhere else in the world. Designed to meet the growing demand from both the daily commuting set and those horsepower-hungry types, the first TorqueFlite came into existence in 1962.

Our TorqueFlite had seen better days. First to go were the old converter, transmission mount (not shown), the kick down lever and gear selector. Next to go was the old oil pan, which when removed, exposed the valve body and filter. The filter screws directly to the valve body, so removing the 10 bolts of the valve body saves you the hassle of unscrewing the four screws keeping the filter on. Since the factory valve body will be replaced with a reverse manual unit from TCI, the old piece was merely thrown away. Finally, all seven bolts holding down the oil pump assembly were unthreaded. The pump - comprised of a pump body, two rotors, and a reaction shaft support - needed to be rebuilt as well.

Built to Last

Surprisingly enough, the sturdy 727 TorqueFlite design survived through the early years of unmerciful “neutral-drop” launches from those racing push-button shifted Chryslers. While such treatment casually murdered one TorqueFlite after another, word quickly spread that the new Mopar slushbox was a force to be reckoned with. Designed to be nowhere near as complicated as GM’s TH350 and 400, and more streamlined than Ford’s C4, the 727 proved formidable behind the HEMI or Mopar’s high-revving LA-block.

But, as it is with most automatics, not all TorqueFlites are the same. Since our project ’69 Dodge Charger Killer Kong was once a mild-mannered two-barrel 383 B-Block-powered daily driver and not a snarling factory-equipped 426 HEMI-powered street bruiser, the included 727 3-speed came woefully ill-equipped to handle the power of a Magnum 440 or a 7-liter elephant – not to mention the 750-horse naturally-aspirated hemispherical-headed monster we’ve got cooking.

Differences between the degrees of performance are various, but usually add up to a discrepancy in the total number of front clutch plates, clutch springs and their respective spring tension, governor weights, the pre-programmed up-shift speed, band friction material and construction, as well as the torque converter stall speed. All of these variants can have a significant impact on the given TorqueFlite’s behavior.

With the valve body out, the front and rear clutch assemblies are exposed, permitting direct access to the front kickdown band. This should be loosened before attempting to remove the clutch. With the bands loosened and removed, the clutches are removed, allowing us access to the planetaries and annulus gears as well as the drum and sun gears. The planetaries, annulus gears, and sun gears all ride on the output shaft, which was next to go.

Spic-And-Sprag

Our particular 727 was in poor shape. Needing as much help as we could muster, we first called Tod Struck at Inline Performance Specialist for some advice. Struck’s been piecing together race and street/strip TorqueFlites for nearly a quarter-century now and knows his way around a Mopar gearbox.

If this doesn't scare you, nothing will. Take a good, hard look at our input shaft (left hand side), as well as our front and rear drums. The front drum in particular is showing significant hazing and oxidation, while the rear drum is only half as bad. In many cases, it's worth chucking up on a lathe and milling down to fresh metal. Our planetaries and annulus gears looked good, with little to no slop in the planetary gears. The pump and input shaft will need quite a bit more attention.

He suggested, “Knowing the kind of power you’re wanting to make, and being that [the '69 Charger] is such a big car, you’re going to want to take extra precautions.”

The plan was simple: less moving parts meant less potential for breakage. We wanted a reverse-manual valve body and a high enough stall converter to spin those tall 4.56 gears to get our big B-Body on its way. Where we came short was the guts. Where should we start?

“A bolt-in sprag, for one,” Struck continued. While impressively strong, the 727 does have an Achilles’s Heel, an overrunning clutch assembly, or “sprag.”

Designed to prevent excessive or potentially catastrophic damage if the transmission is allowed to free-wheel, the transmission’s sprag is a pressed-in housing containing spring-loaded rollers to help slow (and stabilize) the transmission’s rotating assembly.

And since all of the combined kinetic energy of the transmission and engine are absorbed by the sprag, it can – when coming loose – actually start to spin out of the transmission case with destructive effect. To counter this, many racers resort to drilling and tapping the factory sprag, bolting it down in place. Luckily, there’s an easier – and cheaper – way to fix this, thanks to TCI Automotive.

Next the accumulator spring and front and rear servos can be removed. These activate the front and rear bands. When reassembled, a new billet single-piece servo will replace the factory rear servo, as well as new aftermarket springs and heavy-duty retainers to minimize the spongy shift cushioning characteristic to the stock servos. The front servo simply received new inner and outer springs. TCI also included a 4.2 ratio band apply lever, which increases the 'snap' between shifts.

TCI is no stranger to top-of-the-line transmission performance. Since 1968, TCI has earned itself a solid reputation for quality products, whether you’re looking to simply rebuild your transmission or eke out as much bulletproof performance as you can. As for our needs, TCI designed an overrunning clutch kit (i.e. bolt-in sprag) that’s already drilled and tapped, as well as fitted with new springs and rollers.

Since our TorqueFlite needed much more than just TCI’s new sprag kit, we consulted with TCI’s Scott Miller. “A full manual reverse shift-pattern valve body should be no problem on the street,” Miller explained. “But to keep [the 727] together, you’ll need more than just the valve body. You’re looking at our Super Street Fighter kit.”

Next, standing the housing up vertically, remove the access plate to the snap ring, which once removed allows the output shaft to simply fall out. The output shaft features four sets of splines; the first set fits in the front planetary gear, the second set mates the output shaft to the rear annulus gear, the third set holds the governor-park pawl assembly to the output shaft, and the fourth connects to the drive shaft yoke. There's also the gear teeth to drive the speedometer gears. With the shaft removed, the nose cone can be detached easily.

Ready For a (Street) Fight

Since our factory 727 came pretty weak – compared to those TorqueFlites equipped with HEMI-grade components – we counted on a full rebuild of the TorqueFlite. TCI has several levels of performance kits, namely the Sizzler, Street Fighter, Super Street Fighter, and Race transmissions. Officially, the Super StreetFighter is designed to bridge the gap between their StreetFighter and Race series transmissions, for cars producing up to 600 horsepower. Knowing we’d be well north of the 600HP mark, we consulted Miller again.

“Don’t worry. Most of the [components] used in the Super Street Fighter are used in the full Competition Series transmissions as well,” explained Miller. “We’ll use Red Eagle clutches, heat-treated Kolene steels, a Red Eagle flex-style high performance intermediate band, Kevlar high performance bands, a two-extra-quart capacity deep aluminum pan, and a 4.2 ratio band apply lever.”

For those do-it-yourself trans builders wanting to reduce their TorqueFlite’s slippage, Inline’s Tod Struck also suggested, “A lot of guys use all reverse clutches. They’re thinner than the forward clutches, which allows you to pack more in. It’s an old trick.” While we weren’t going to be employing this tip, it was a helpful bit of advice.

The governor gear slides on the output shaft like a collar, and works to control shift points. According to Allpar: "Two cast iron sealing rings, the governor body-park pawl assembly and the governor valve-governor weight assembly all work together to send the governor signal to the valve body to tell it to operate various shift valves, controlling up and down shifts. There is one snap ring used to hold the governor body park pawl assembly secure on the splines on the output shaft."

Coming Through In a Clutch

Disassembling our transmission only took a short amount of time. Starting from the outside and working our way in, we removed the old torque converter, which we believe spun around 1200-1600RPM from the factory. Next came the cracked and broken rubber cross-member mount, speedometer gear drive, and shallow stamped steel pan. Our new TCI aluminum pan adds over 2 additional quarts of ATF and is finned for better cooling, a stark improvement over the dented steel one.

After polishing the output shaft to clean up its surfaces, it was time to put it back in. But before we could slide it back in place, TCI pulled out the old overrunning clutch assembly, or "sprag." TCI's bolt-in sprag bolts in through the rear of the housing, where the previous sprag was merely pressed in. Now installed, the output shaft was fitted with the governor pawl and bolted down with a new gasket.

With the pan gone, we had direct access to the valve body. Normally referred to as the “brain” of the transmission, the valve body acts very much like your engine’s camshaft, with pre-programmed points and circuits mandating shift points and fluid pressures.

Since we’re going with a reverse-shift-pattern manual valve body, we no longer need to worry about slippage as we’ll be shifting our automatic manually from here on out.

Removing the valve body required the twist of ten bolts with the attached filter (held on by four screws), and, when gone, revealed the clutch drums and servos that truly make our transmission come to life. The oil pump assembly is held in by seven bolts.

Many find it difficult to pull out without the use of a thread-in slide hammer or having to press it forward from the inside. Either way, with the pump out, the planetary gears can be removed easily; held in by a snap-ring (or “circlip”) the planetaries, clutches and drums all slide out in sequence.

It’s a smart idea to double check your planetaries for any “slop” in your gears. Thankfully, our TorqueFlite’s planetary gears were in good shape and showed a safe amount of side-to-side “play.” Unfortunately, our clutch drums exhibited some surface rust. A couple passes of emery cloth or steel wool knocked off the oxidation without much ado. Otherwise, we’d have to turn the drums down on the lathe. Many shops, in fact, will mill a step into the drum to give the band a guide. Yet another little trick that some like to use.

Reassembling the rear gear train is surprisingly straight forward. First, install the rear band, attaching it to the rear band arm (or strut). Next, slide in the rear drum, indexing it into the bolt-in sprag. The sprag should allow the drum to spin easily clockwise, but lock when trying to turn it counter-clockwise. Next, insert the output shaft. This step should be followed by inserting the rear annulus and planetary. Next, slide on the drum with the two sun gears. The front annulus and four-pinion planetary (big block-equipped 727s came with a four-pinion versus small blocks, which got a three-pinion). A single snap ring holds the whole assembly in place (shown).

Getting Our Act Together

Putting the TorqueFlite back together was merely a reversal of the disassembly process, only doing so a bit more carefully and using fresh, new components. With with the tail off, TCI thoroughly cleaned the bare housing, blowing out the circuits before reassembly. TCI was mindful to apply a dab of grease to each hard contact point. While the TorqueFlite will be running TCI’s Max Shift ATF, the added precaution ensures a safe installation and additional insurance from unneeded wear.

The rear gear train went on quickly after installing the bolt-in sprag. The rear drum friction band goes in first, mating up to the rear band articulating arm. The arm is actuated via a sprung servo (which we replaced with a billet piece), and constricts the band when shifted either in low (first gear) or reverse. The clutch drum slides in next, which indexes into the bolt-in sprag. The sprag allows the drum to spin clockwise, but locks it from turning counter-clockwise.

With the drum in, the output shaft can go in next. The rear annulus and three-pinion planetary go into the drum afterwards. Many top performance builders prefer that the three-pinion planetaries be swapped out with four-pinion billet pieces. While our front planetary was a four-pinion, we kept our costs low by retaining our rear planetary. We’ll make sure to keep the down shifting (or engine braking) to a minimum.

Since our TorqueFlite's drums were oxidized - but not excessively worn - it wasn't necessary to turn them down on a lathe. Rather, they were simply scrubbed down with some steel wool until they looked brand new. With everything out, the bare 727 aluminum case was given a quick cleaning before the reassembly. Rebuilding the front and rear clutches require a bit more than just repacking the discs. First, TCI pressed out the snap ring, the retainer and the seals before swapping out the clutch springs and new seal rings. Using Red Eagle clutches and heat-treated Kolene steel plates, TCI alternated between the steels and clutches until five of each are pressed beneath the pressure plate. The process is the similar for the rear drum, except including the installation of the input shaft, as well as the addition of a new diaphragm, spacers, wave and flat snap rings, and of course a new bushing.

The forward drum (fitted with the two sun gears) was next followed by the the front annulus and aforementioned four-pinion planetary. Capped off with a single snap ring over the end of the output shaft, the whole assembly is held in place.

Joining the output to the input shaft is the forward gear assembly. The front and rear clutch drums were repacked with new springs, retainers and seals before the Red Eagle clutches and new high performance steels could be shuffled in. One after the other, the rear and front clutches index together on the input shaft before the pump goes on. But before the pump can be installed, the forward band is inserted.

Once sealed up, TCI rolled the 727 over and adjusted the bands properly, torquing the adjustment screws to 72 ft. lbs. Its usually a good rule of thumb to adjust the screws once, over-tighten them a turn or two and back them off before readjusting the screws back to the proper torque rate. This is a good tip particularly as this will set the bands.

With much less hardware to worry about, the manual valve body requires much less effort to bolt down than a regular automatically-shifted valve body. Attached with a new filter, the bottom end of the 727 was all but ready. Before buttoning up the new deep pan, the transmission was pressure tested. This test ensures that the new servos actuate the band arms, while the transmission is systematically rolled through all the gears. It’s the last bit of double and triple-checking that goes into a TCI-built performance transmission.

With the front clutch assembly in and properly indexed, TCI slid in the new Red Eagle flex-style high performance band. The forward band can go on in either direction, as long as the split is pointed outward toward the kickdown lever. Made with a Kevlar lining, these high performance bands are capable of handling up to 1,000 horsepower. Next, the heavy duty band struts are slid into place and tightened down by the adjustment screw. Following this step, the bands are left to be adjusted later as the rebuilt oil pump is bolted back into place. There's a specific way the pump should bolt down to keep all the oil passages open. Make sure the oil pump and the gasket are aligned properly or you risk blocking off your transmission's circuitry.

Buttoned Up And Ready To Burn Some Tire

With the pan on with a fresh gasket, Kong’s newly-TCI-rebuilt 727 TorqueFlite was given a fresh coat of paint (as is the TCI custom) and shipped back home, accompanied with a new TCI Outlaw Shifter, a Super Street Fighter torque converter, and one of TCI’s Performance Transmission Cooler kits. We love the Mopar-appropriate pistol grip-design of the billet aluminum Outlaw shifter, and even toyed with the idea of maybe swapping out the black grip with a woodgrain replacement. Although the Outlaw can come with an electric shifter kit and one- and two-button triggers, we opted for the simplest setup with a Park/Neutral safety switch.

Transferring the power from the crank flange to the transmission is our new high-stall torque converter. Made with furnace-brazed fins, needle bearings, and a hardened, pre-ground hub, the Super Street Fighter converter is the right pick for our big block set up, particularly as we’re running 4.56′s with 30-inch tall tire. Pitched with a 3,800-to-4,000RPM stall, our 9-inch converter will flash pretty dang hard.

Totaling out our care package from TCI was their Performance Transmission Cooler kit. Constructed from aluminum and powder coated black with #6 AN fittings to work with high pressure lines, we’ll definitely put this to good use.

Building a hard-hitting engine is always the flashy, fun thing to talk about, but without the proper gearbox to back up all that power, your big and brash big block won’t have anywhere to go. We’re working on Killer Kong’s powertrain a little backwards on purpose because we want to emphasize how crucial the rest of the package is. While a stroked lightweight HEMI is a cool catch for this project car, it’s the collaborative effort of all the parts that make it a success, and with TCI’s help, we’ve got one less part to worry about.

The rear band adjustment lever is torqued down to 72-pounds and backed off two turns. This allows enough slack in the lever to keep the band loose, but not sloppy. The front band is tightened down identically to the rear lever, making sure to back it off two turns. With the bands adjusted, the reverse-pattern, manually-shifted valve body can be installed. Designed for competition use, TCI's manual valve bodies run higher line pressures than automatically shifted transmissions, which prevents clutch slippage under high loads. Before buttoning up the TorqueFlite, the transmission is pressure tested to make sure that all of the servos respond as the transmission is artificially shifted through all the gears. With the 727 complete, TCI painted the Mopar gearbox in a coat of gray paint and install their deep cast aluminum pan.

With our mighty TorqueFlite buttoned-up and ready to go in, we wasted no time in getting Killer Kong up in the air and ready for the install. We've got some plumbing to do to hook up the new transmission cooler kit as well as the new Outlaw shifter, but we'll have another update on that install coming up soon!

The battle for supremacy against the clutch-equipped cars isn’t the only front the torque converter is fighting on however, as an internal struggle between two differing approaches to converter design and methodologies for planting the power to the ground have ensued. On one side, you’ve got the traditional converter design that operates on the basis of slippage, and on the other, the the lockup converter that’s clawed its way back into the fight.

Over the last two years, lockup torque converters have become a rather popular conversation piece in the context of high horsepower racing vehicles, thanks in due part to record-setting performances and an NMCA Pro Street championship, leading some to the belief that such an approach is the just the latest magic trick of the week that the industry has pulled out of its hat. That, however, couldn’t be any further from the truth.

To learn more about the past, present, and future of lockup torque converter technology, we’ve sough out some of the top manufacturers in the industry who at differing times have put their own revolutionary touch on the age-old converter.

The Companies We Talked To

Pennsylvania-based Transmission Specialties was one of the earliest manufacturers of lockup converters for high-end drag racing purposes, and continues operation today with more than 30 years of renowned experience in the market.

ATI Performance Products, which is virtually synonymous with the sport of drag racing, is well known for its line of Superglide transmissions and unparalleled quality, and has largely spearheaded the recent resurgence of the lockup converter.

Hughes Performance meanwhile, which opened its doors in 1971, is regarded as one of the top transmission and converter manufacturers in the drag racing market, with innovative products for race cars ranging from Super Street to Pro Modified. Hughes is the latest company to throw their hat in the extreme performance lockup ring with their new XP5 unit.

TCI Automotive, perhaps the most familiar name in the driveline marketplace, has been supplying automotive enthusiasts and racers with transmissions and converters for some 40 years, and today offers a complete line of lockup torque converters for many of the popular street and strip combinations.

A History Lesson In Lockup Converters

The traditional torque converter, as many of our readers are acutely aware, is a fluid coupling device that’s used to transfer rotational forces from a power source, in this case an internal combustion engine, to a rotating driven load. The torque converter acts like a mechanical clutch, allowing the load to be separated from the power source. This “donut” converts fluid pressure to lock the converter output shaft, thus transferring the engines power and torque to the driveshaft. Through what’s known as torque multiplication, the difference between the input and output rotational speeds provides what is essentially a reduction gear. Traditional racing converters however, exhibit some level of slippage at all times.

Transmission Specialties first developed their Pro-Line 6000 Powerglide transmission and converter system in 1998 and offered it through 2004 when some prominent organizations banned the use of lockups.

A lockup converter, just as the name implies, takes the traditional approach a step further and eliminates this horsepower-robbing slippage by completely locking the forces of the flywheel to the output shaft. In essence, it’s a 1:1 mating. Such a method has been used for decades in street vehicles, but it’s believed to have first been instituted for hardcore racing purposes back in 1975, when Steve Griner and Dave Coan partnered to build the first lockup racing converter.

These first iterations, which were mated to TH400 transmissions, locked up in first gear and at the time were said to be worth some three tenths and three miles per hour on average. API Racing Transmissions and Transmission Specialties later built their own versions.

With the records to prove it, the early lockup converters and automatic transmissions worked very well, but they were also plagued by issues that proved to be their downfall. Broken input shafts and leakage were a regular occurrence, but when they held together, they actually worked so well that some sanctioning bodies banned their use.

Transmission Specialties first developed their lockup unit in 1998, known as the Pro-Line 6000, which consisted of the transmission, converter, motor plates, adapter plates, air cylinder, and the works. At the time, racers the likes of Steve Kirk and Bob Rieger had these units in their race cars.

“They worked really, really well,” exclaimed Ken Kelley of Transmission Specialties. “Bob had one in his Firebird and was going 200 miles per hour back in 1998, which was just unbelievable at the time.”

Continued Kelley, “The problem back then was we were breaking input shafts and twisting the splines trying to get them to lock up, so that was their real downfall.”

A poster showing an exploded view of the Transmission Specialties Pro-Line 6000 lockup torque converter, displaying the extra clutch packs contained inside, on the wall at their facility in Pennsylvania.

When the venues banned the use of the lockup converters, Transmission Specialties and other manufacturers who had or were planning to develop one scrapped their plans prior to or around 2004 and put their focus back on the traditional converter line. API meanwhile, has continued to produce their lockup unit over the years and still does to this day.

But in recent years, the lockup converter has seen a resurgence in the racing world, namely in Pro Modified, Pro Street, and similar high-powered machines. In 2009, ATI Performance quietly outfitted Chris Rini’s Pro Street Dodge Stratus with a then-secret piece and set the class abuzz with unexplainable elapsed times and speeds. It didn’t take long for the cat to get out of the bag, and it was on from there.

Hughes Performance has just come to market with a version of their own, known as the XP5, that also aims at the mega horsepower realm.

“This was a project that we actually started working on in the first part of last year, and we really think that this is the next evolution of automatic Powerglide transmissions in drag racing applications,” explains Hughes’ Pete Nichols.

Lockups 101

So how does a lockup converter work exactly?

To understand how a lockup works, one first needs to understand how a torque converter functions. For the sake of avoiding web redundancy, click over to How Stuff Works and check out their great resource to get yourself up to speed.

ATI's SuperGlide 4 Powerglide transmission, designed for use in high-horsepower drag racing and other motorsports applications.

“The idea behind the lockup is that you get the torque multiplying advantages of a torque converter at the starting line and the efficiency of a clutch on the top end. In theory, a car that previously had a clutch should run the first half of the track quicker because it has more torque available at the starting line, and then it retains the clutches’ efficiency from there on,” says Nichols.

A lockup torque converter sports an extra set of clutches that are situated on the backside – or cover side – of the converter, of which pressure is diverted to from the transmission through a small cavity in the input shaft at a specified point. This pressure exerts movement on an internal piston that in turn locks the clutches together, creating a locked coupling between the turbine, cover, and input shaft. At this point, the converter is locked up much in the same sense as a clutch. In essence, it’s a hydraulic system.

Tested in 2009 and taking NMCA's Pro Street category by storm in 2010, ATI's new Outlaw Lockup torque converter has led the reemergence of the lockup in heads-up drag racing.

“The struggle with this functionality is producing the necessary pressure all the way through the input shaft,” explains ATI’s JC Beattie. “You”ve got a lot of horsepower and you’re drilling holes in the shaft, you have a significant amount of heat, O-rings that need to live, and of course everything has to remain straight. It’s certainly a big challenge when you’ve got a car that’s going zero to 230 miles per hour in six seconds.”

While different on the inside, lockup combos are much the same on the outside. The Hughes unit for example, starts life as a conventional Powerglide transmission case but is one inch longer overall to accommodate the one inch taller converter that packs the additional clutches. The transmissions feature a unique input shaft, a different front pump, and valve body.

Hughes Performance is the most recent manufacturer to join the lockup fraternity with their new XP5 system. This brand new combo is based upon an original Powerglide transmission, albeit measuring one-inch longer then standard and featuring a larger input shaft and an improved front pump and valve body.

Explained Nichols, “We just took a conventional Powerglide design and added the lockup circuitry to it. The shaft is physically larger in diameter at 1-1/4″ and is made of a special steel alloy, so the shaft itself is much stronger than a conventional Powerglide shaft.”

That increased shaft diameter and strength, a culprit of the early lockup combos, has made handling upwards of 4,000 horsepower without issue.

As one might expect when an engine shifts from slip to complete lockup, the engine RPM, even in powerful big blocks, is dragged down to a point that even the most out-of-tune set of ears can pick up on. At the time of Rini’s testing, some believed this audible tone to be a three-speed transmission, but that wasn’t the case.

“You’re not changing any gear ratios or anything like that; it’s still just a two-speed transmission,” states Beattie. “But the slip that you would have in a loose converter is eliminated. It does change the RPM, but you’re not mechanically changing a gear.”

Hughes Performance's new XP5 lockup torque converter, available in 9.5 and 10-inch designs, is activated by a 12V solenoid contained within the transmission.

The point of lockup differs as greatly as the combinations that do or could potentially use one, and its operation is controlled via an electronic solenoid or a timer that comes off of the transmission valve body and uses line pressure to hold the lockup clutches inside the converter. This solenoid can be activated with a button or switch mounted in easy reach inside the cockpit, and thus one can actually alter the lockup point to cope with tirespin or tireshake just as a clutch racer would alter their gear changes.

The Lockup Makes a Comeback

At the ADRL season opener in Houston in March, Texan Doug Reisterer put the lockup on fine display, piloting his ’68 Camaro to a 3.84 at 191 that was good for third in the Pro Nitrous qualifying order. His monster cubic-inch nitrous bullet was backed by ATI’s Outlaw lockup.

Rini, meanwhile, holds the current Pro Street national record at a stout 6.03 seconds at 234.86 miles per hour with his similar ATI combination. Chris also held the record in 2010 at 6.157 and 233.20. Along with the quarter mile performance, his brand spankin’ new ’69 Camaro has recorded a 3.91 to the eighth mile this season.

NMCA Super Street newcomer Jesse Violante has been testing ATI's new Outlaw Lockup torque converter in his nitrous-assisted '69 Camaro this season.

“The lockup program has been unbelievable,” says Rini. “We can run killer front half numbers and put up big mile an hour, so we kind of get both ends of the racetrack. We lock that thing up like a clutch car and run 235 with a Powerglide with a nitrous motor. And that’s big, because nitrous motors only have so much steam at the finish line.”

Whether running the eighth or quarter mile, Rini has found the lockup to his liking and believes it to be superior for his combination even in the shorter distance where lockup is never achieved. And with over 100 runs on the very same converter without fail or major servicing, it goes to show that the early lockup issues are a thing of the past.

“Right now, the only thing I have in my trailer is lockups. Sure they carry a little more weight, but it hasn’t hurt the ET at all,” said Chris.

Also in NMCA competition, Super Street newcomer Jesse Violante is running an ATI lockup in his new ’69 Camaro, and Tony Nesbitt is said to have his eyes on one, as well.

PSCA Pro Street racer Kelly Bluebaugh recently became the first racer to put the new Hughes Performance XP5 lockup through it's paces aboard his nitrous-fed Chevy Monte Carlo. After making the switch from a clutch, the WFO team has had to rework their entire combination, but they, along with Hughes Performance, expect a significant improvement in performance in the near future. Image credit:

PSCA and WCHRA Pro Street racer Kelly Bluebaugh is the first racer to get the Hughes XP5 on the racetrack aboard his nitrous-fed Monte Carlo, running a 6.56 on it’s maiden outing this spring.

“Kelly’s car was originally equipped with a Lenco and a clutch, and his nitrous and suspension tuneups were all set up for that. So he’s having to re-tune the entire car for the automatic. But once he gets it all sorted out, we’re expecting 6.20′s out of it pretty quickly,” says Nichols.

Bluebaugh is having a controller made that fully automates the lockup function based on RPM, allowing the lockup point to be set at any point on the track. With that, he’ll be experimenting along with Hughes locking the converter in low gear and/or earlier distances on the racetrack.

In addition to Bluebaugh, Hughes also has four other XP5′s slated to hit the track soon, including two X275 cars, a Top Dragster, and a West Coast Nostalgia Funny Car.

Turbocharged cars, because of their spooling needs, necessitate a loose stator and blade angle to accomplish this and keep the car from blowing the tires off. But like a freight train, once the boost and power management come in, they go from slip-needy on the bottom end to pouring every last coal to it on the back half. The result with traditional converters has been broke transmissions and ballooned converters.

NMCA Pro Street competitor Jeff Lutz has been dialing his combination in using a standard ATI torque converter and once there, will make the switch to an Outlaw Lockup combo to put some even better numbers on the boards.

ATI has been working closely with NMCA Pro Street competitor Jeff Lutz on his turbocharged ’98 Monte Carlo to fine tune the lockup setup, albeit with an initial step that doesn’t involve a lockup.

Explains Beattie, “The best way to get his car dialed in is to get the converter sorted out without the lockup, and once we get there, we can put the lockup in there and get the rest of the ET and mile per hour.”

NHRA: No Home For The Lockup

In the early 2000′s, the NHRA banned the use of lockup torque converters in a move considered to be as much about safety as it was the performance advantage. And to this day, the ban remains in effect in all classes, including Pro Modified, the Top Alcohol categories, Top Dragster, and Top Sportsman.

Because the quarter mile is where a lockup converter truly shines, the NHRA venue is where ATI, Hughes, and others believe they could best display their technology, and they say the decision is unfounded and ultimately detrimental.

Reigning NMCA Pro Street champion Chris Rini has been a leading proponent of the allowance of lockup torque converters in NHRA Pro Modified, where he feels they offer no advantage over a clutch-equipped car.

When asked if he would run Pro Modified if the lockup were allowed, Rini replied with an emphatic “yes.”

“I don’t even understand why they have the ban. I think it’s just because they don’t understand it. A clutch car is locked up at the finish line, so why isn’t a lockup allowed? They’re doing the same thing. I’ve made some phone calls to the NHRA about it and I can’t get a straight answer out of anybody. I’d go there in a heartbeat if we could get that rule changed.”

Rini believes the lockup converter gives automatic transmission-equipped Pro Modifieds a better chance to compete, and with the struggling car counts seen this season, might entice more racers to show up. As well, because an automatic car goes down the racetrack nearly every pass, it only adds to the entertainment value.

“They need to modernize and get with the times,” Rini says. “When you talk to them, they reference things that happened a decade ago, but times have changed.”

Not Just For The Extreme

Lockup torque converters may be making a resurgence in the high-end drag racing world of late, but they certainly aren’t limited to this segment of the arena. Several manufacturers, including the folks at TCI Automotive, have developed and offer lockup converters of several size variations for GM, Ford, Chrysler, and AMC drag racing applications more suited to bracket-style racing.

“At one time, a lot of people with higher horsepower, 550 to 600 horsepower applications wanted a non-lockup because the converter clutches wouldn’t hold to be locked up and raced with,” explains TCI’s Scott Miller. “Now, the technology in clutch material and converter and transmission design is vastly improved. You can run a 4,000 or 4,500 stall converter and it still be a lockup, and the clutch will hold up.”

An exploded view showing the internals of one of TCI's Lockup Drag Racing torque converters. Images courtesy

Like their several thousand horsepower brethren, these such converters function in the very same manner and provide the same benefits from their zero slippage operation, such as improved elapsed time and almost certain trap speed gains.

“The 1:1 ratio really helps out on your top end mile per hour and a car will just run a lot better that way,” says Miller. “And there’s also less heat, of course.”

For converters built for such purposes, one area in which they differ from the extreme applications we’ve spoken of previously is in the engaging process. The method differs depending on the transmission the converter is mated to, and in some cases the functionality is much like a Pro Modified car with a toggle switch, while others are done without driver interaction.

TCI produces a full line up lockup drag racing torque converters of the 9, 10, and 11-inch variety for GM, Ford, Chrysler, and AMC applications.

“On the older 700R4′s, you would just have an on/off switch wired into the transmission, and when it goes into whichever gear you want it to lockup in, you’d flip that switch on. The other option for later model electronic transmissions, like the 4L60E or 4L80E, it’s all controlled by a computer. It would all be programmed using a tuner or a standalone transmission controller,” explains Miller.

While aimed at engines producing in the neighborhood of 400 too 600 horsepower like that of a street car, Miller explains that these are primarily designed for racing use.

“The only time anyone would really want to use one of these on the street would be for grudge racing or just playing around. It’s not something that you’d want to drive every day.”

Lockup converters are but one of a handful of approaches to torque converter functionality, and while none is deemed superior in all applications and situations, manufacturers like ATI and Hughes believe there are some distinct advantages to the lockup, and they’re firmly behind the belief that the lockup converter is the way of the future. And while the war between not only the staunch supporters of the automatics and the clutch but amongst the bright minds in the automatic transmission and converter world is sure to wage on for some time, it’s evident that the lockup is back and it’s not going away quietly this time.

When we first proposed building a HEMI-powered ’69 Dodge Charger in the same budget-minded, do-it-yourself style as say, a ’75 Nova, we were nearly laughed out of the room. Building a classic Mopar carries a certain stigma – particularly when compared to most any Chevrolet or a first generation Mustang – that parts are exceptionally rare and therefore expensive; unless of course, by “classic Mopar” you mean a worn out front-wheel-drive Omni (which we don’t).

Currie Enterprises, while excelling at producing some of the strongest street, hot rod and off-road rearends, is also comprehensive fabrication and machining facility, capable of rebuilding most factory-style housings. Before any work could commence, Currie hot tanked and cleaned our old Dana housing of any remaining grease and gear oil residue.

In Killer Kong’s original introduction, we mentioned that while battered and bruised, we picked up a considerably rust-free and surprisingly complete ’69 Charger for $1,200. In its original form, our Dodge came factory-equipped with an open-differential (i.e. “peg leg”) 8.75-inch rear.

While the 8 3/4″ served many automatic-equipped big block Super Bees, Road Runners, and even the infamous Daytona aero-cars valiantly, it was the legendary Dana 60 rear that was drafted to take the abuse delivered by the 426cui HEMI and Mopars equipped with Chrysler’s A-833 four-speed.

Where to Find One Cheap

Long before the first ’66 Dodge Coronet and Charger R/Ts were made available with the Dana, the Dana Corporation-built housings were first employed by heavy-duty Ford pickups in 1955, with Studebaker’s 3/4 and 1-ton trucks following shortly thereafter.

Yet, it was Dodge and Plymouth who were the first and only of the Big Three to use the Dana 60 (with a ring gear diameter totaling 9.75-inches, a full inch larger than the smaller 8 3/4 and .75-inch larger than Ford’s best) in passenger vehicles.

Unfortunately, finding an original Dana 60 housing from the short five-year run (1966-1971) for ‘Kong proved both difficult and expensive. Since we were more concerned with having a rear that was both correct for our car (i.e. no Ford 9-inches) and stout enough to take all that we planned to throw at it, we needed to look elsewhere.

Thankfully, Dana 60 housings aren’t all that exotic and can be found in nearly a quarter-century’s worth of pickup trucks, SUVs, and Jeeps. We found a Ford F-350 that was getting parted out, and nabbed ours for $50. Yes, you read that right, $50 for the whole thing.

Once cleaned, Currie carefully measured our housing to match factory Chrysler specs (offset) before chucking it up on the chop saw table where the old Ford ends were cut off.

Of course, we couldn’t simply bolt in our $50 Dana. Before heading over to Currie Enterprises in Anaheim, California, we cleaned up our used housing, ground off the Ford perches and brackets, and removed the worn out carrier and pinion gear. We also disassembled the kingpin knuckles which would be cut off and replaced with the proper end caps.

The big difference between our salvaged Dana 60 and the original passenger-style Chrysler housings was a four-bolt perch for a factory-supplied pinion snubber, which kept the pinion from rotating when under heavy load. Since we’re planning on using a pair of Cal-Trac style traction bars, the need for a snubber was resolved.

Welcome to Currie! Let’s Get Dirty

Showing up with the bare Dana 60 housing at Currie, we met with Brian Shephard who walked us through Currie’s in-house capabilities, “Our full-service, one-stop shop includes a tear down and cleaning facility, full machine shop, welding shop, gear setup and assembly areas, and unit final assembly stations allowing us to service basically any need a customer may have on any of the rearend types that we service.”

Before welding on the new billet bearing end caps, the tube ends are chamfered to accept a deeper weld, making for a more durable connection. Currie's fabricators have these unique jigs - utilizing lathe chucks - to fully rotate the housing while welding on end caps and spring perches and bracketry.

Currie’s portfolio is oddly diverse, from street and strip automotive rears to mountain trail “jeeping” housings, to high-speed baja racing setups, all the way to mining and military applications. Surprisingly, conventional automotive rear ends only account for only about 40-percent of Currie’s business. Shephard continued, “After 52 years in business you could say we have rearends down to a science and they’re made in the USA! From building 100% new units to rebuilding as we did here, the customer gets a premium job done with premium parts and components every time – that’s the only way we work.”

Concerns whether welded end caps can hold up to high horsepower applications can be absolved by the proper weld. Using the right pattern combined with the speed of the wire can greatly affects penetration can determine whether a weld is weak or strong.

Stripped Down And Built Back Up

Our once-Ford-now-Dodge Dana 60 was quickly carted off to Currie’s chemical cleaning cabinet where a caustic steam bath stripped the housing bare of any grease, gear oil, grit, and debris before fabrication could begin. Once cleaned, the housing was chucked up on a jig and measured and marked for narrowing.

Although we’re keeping the housing within stock Chrysler measurements (a 44-inch center of pad-to-pad width and 54-inches from one backing plate flange to the other), the axle tubes needed to be shortened for the new bearing end caps to be welded on. A benefit of using a full-sized truck housing are the thicker tubes (up to 1/2-inch), which allowed us more material to chamfer down to build a better weld bead.

Ready to put some heat to the housing, a pair of machined aluminum discs were bolted into carrier bearing races as a six-foot rod of round aluminum stock was slid into place. A third disc was fit into the end of the new end cap and slid onto the bar to hold the cap in place, ensuring that the tube end stayed properly aligned while being welded.

Squared and true, a sequence of slow, high heat beads bonded the end caps to the axle tubes, overlapping one over the other. Wire-wheeled clean, the housing was measured and squared up again to receive the factory-style leaf spring perches supplied by Competition Engineering.

With all of the welding completed, the housing was sent to a material blaster, where the housing is stripped by media that strips and welding flash, paint, and solvents from the metal, leaving completely virgin, bare steel.

Once Currie completed all of the fabrication work, the housing was sent back to the material cleaning department for an aggressive media treatment. This stripped the housing down to bare metal without the use of caustic chemicals while knocking off any welding flash, removing any embedded contaminants, or oil residue, making it now ready for assembly.

Building A Budget Dana 60 By The Numbers:

• Dana 60 Chrysler Rear Housing (44″ center of pad-to-pad width, 54″ between backing plate flanges width)
• Currie Forged Alloy Extreme 35-spline Axles, offset pair 28-7/16″ and 27-1/16″ (# CE-1014)
• Currie Sealed Large Axle Bearings With O-Rings (# CE-8000S)
• Motive Gear 4.56 ring and pinion (# D60-456)
• Detroit Locker 35-spline (# DET225S-29)
• Competition Engineering Rear Axle Spring Perches, 2-1/2″ wide (# 85090)
• Yukon Gear Billet Yoke (# YY D60-1350-B)

The Filling Is Always The Best Part

Currie's forged alloy axle shafts are made to order, from milling the 35-splines, to drilling and tapping the blank axle flanges for a set of large 5/8-inch lug bolts.

In planning for Killer Kong’s powertrain, we’re looking at building a big-cube HEMI pressing out somewhere between 650 and 700 horsepower, with a reverse manually-shifted 727 Torqueflite automatic snapping quick shifts between 6,000-to-6,5000rpm on the rare occasion that its on the track and not on the street.

That being said, we knew we had to build this Dana with some pretty stout stuff. We first contacted EATON for a Detroit Locker differential. Thankfully, things have changed since the early days, and today’s Lockers are nowhere as clanky and noisy as they were twenty years ago.

Plus, since the Charger is far heavier than so many stripped-down pony cars running similar setups, our Locker won’t be loosely indexing through gears around corners.

Ultimately, the Detroit Locker was the logical choice considering the power we were looking to make and needed to put to the pavement while not sacrificing streetability as we would with say, a spool.

Next, we made a call to Motive Gear, who rushed out a 4.56 ratio ring and pinion set. Normally, such a low gear ratio would make highway driving arduous, but as the Charger is close to 3,800-pounds and running a 30-inch tall rear tire, the aggressive gearing made the most sense.

Of course, Currie supplied all the new bearing races, seals, shins, and bearings, as well as a pair of 35-spline forged alloy axle shafts. After milling the axle shaft with the 35-count splines, the blank axle flanges were drilled and tapped for the larger 5/8-inch lug bolts (at factory Chrysler 5 x 4.5-inch pattern).

Weapons of war: EATON's Detroit Locker is known in performance circles as being "grenade-proof," and we believe it. That, combined a burnout-happy set of 4.56 gears from Motive Gear, our Dana 60 is quickly adding up to be one mean machine.

Before final assembly, a bit more work needed to happen. Our Currie specialist, Abraham, first notched the carrier bearing perches. This allows gear oil to flow freer through the axle tubes and the housing, reducing fluid and bearing heat. Next, to get a baseline for the new gears and Detroit Locker, Abraham loosely assembled the pinion and carrier with a variety of different shims to find the perfect alignment. Tolerances need to be precise with applications like these, or the extreme forces within the housing can cause accelerated wear and possible mechanical failure.

It's the little tricks picked up over the years that make for a well-oiled rearend (pun intended). By scoring the bearing seals, gear oil is able to pass freely from the axle tubes to the carrier, while passing continually through the carrier bearings. Cost? Nada.

Using a dial indicator to check the backlash and some yellow marking dye to check the engagement of the ring and pinion gears, Abraham was able to adjust the final alignment by shimming the carrier bearings and pinion gear for proper engagement.

To install the pinion gear, first a new bearing race needed to be pressed into the housing. Next, the pinion gear was assembled on a vertical press with a cone bearing and a collection of measured shims. From the front of the housing, a second series of shims, bearing, slinger bearing, crush sleeve and an oil seal were pressed in, tightened down with a new Yukon Gear yoke and nut, with the pinion preload adjusted.

With a dollop of red thread locker, the 4.56 ring gear was bolted to the carrier, with each bolt torqued down to 110-pounds. Assembled with the right amount of shims, the carrier bearings were pressed on. Covered in a bead of red Loc-Tite, the races covered the carrier bearings as the whole Locker was lowered into the housing. Finally, the caps were torqued down to 80 lb-ft.

The key to building a stout, long-lasting rear is in the preparation. Checking, double-checking and rechecking tolerances and play is central to putting a rearend together that will last.

With our center section dialed-in and fully assembled, the 35-spline axles were assembled – much like the pinion gear – on the vertical press, sandwiching the sealed axle bearings and backing plates. Having been pre-drilled and tapped for the large lug bolts, they were threaded in from the backside of the axle flange with another trusty dollop of red thread locker.

Puttin’ On The Brakes (Literally)

All of Currie's heavy duty 11-inch drum brakes come new and ready for service, either on a hot rod, a street car or a drag racer. The drums come blank and are specifically drilled to match your lug pattern and size.

But before the axles could be slid into the housing and indexed into the Detroit Locker, we attached our new 11-inch drum brakes to the end caps. The choice to run drums over say, a new set of aftermarket 4-piston calipers was two fold.

Currie’s Brian Shephard made a convincing argument, “Well, in [Killer Kong's] application, a foot-brake drag racing application, you just have to think about the sheer surface area of the pad material of the drum compared to the disc brake. When you are trying to hold back a 4,000 lb., 600-plus horsepower car with the brakes – you need surface area!”

That surface area was dramatically increased from our Charger’s original factory specs; stepping up from 9-inch drums to heavy duty 11-inch drums was a no-brainer. Thankfully, 11-inch drums are still in abundance in most automotive salvage yards, you just need to look out for Chrysler-made station wagons, light duty trucks, and vans from the late 1960′s all the way through the mid-1980′s.

Secondly, was the most obvious, cost. While rear disc brakes have become more common, they are still – on average – $600, while a solid set of HD drums will set you back close to half of that. And since we’re putting in Currie’s brand new 11-inchers, we don’t need to change any of our factory brake cables. Oh, the simplicity!

All of Currie’s drums come blank and are specifically drilled to match the lug pattern and size of the axle package. Since we went with the larger 5/8-inch diameter lugs, Currie bored out to match our Dodge’s 5 x 4.5 pattern.

From drum to drum, filled with some of the stoutest running gear available for a street-driven Mopar, this Dana 60 came in at nearly half the cost of purchasing a new one.

From junkyard scrap to a bad ass Dana 60 worthy of 1,000-horsepower in a day, we buttoned up this monster axle housing for half the cost of purchasing a brand-new 9.75 rear from an aftermarket company. While nothing nearly as exotic as some of the stuff they’re capable of building, Currie Enterprises made short work out of this budget Dana 60. Now, we just need to bolt it up into Killer Kong and get her rollin’!

]]> http://www.dragzine.com/tech-stories/drivetrain/currie-builds-killer-kong-the-ultimate-budget-dana-60/feed/ 0 http://www.dragzine.com/project-cars/project-all-air/building-a-stout-powerglide-with-atf-speed/?utm_source=rss&utm_medium=rss&utm_campaign=building-a-stout-powerglide-with-atf-speed http://www.dragzine.com/project-cars/project-all-air/building-a-stout-powerglide-with-atf-speed/#comments Thu, 24 Mar 2011 21:10:17 +0000 Bobby Kimbrough http://www.dragzine.com/?p=54378 Powerglide: [pau̇(-ə)r glīd] noun. : A two speed transmission designed by General Motors available primarily on Chevrolet automobiles from 1950 through the early 1970’s.

ATF Powerglide: [a-t-f pau̇(-ə)r glīd] PROnoun. : A completely new bulletproof automatic transmission loaded with top quality parts and features. Available in stages 1 through 5.  The High Horsepower ATF stage 4 Powerglide is rated to 2,500 horsepower and is known to provide enough drive through the rear end to propel the host vehicle past other cars fast enough to suck the contingency stickers off them.

Automatic Transmission Factory (ATF) located in Davie, Florida, never seems to rest on their laurels. These are the folks that continue to push the envelope on machining some of the most creative transmissions to hit the track. Their 7,000 square foot facility is armed with a 12 lift garage and chassis shop with 2 HAAS CNC machining centers and a crew of diehard ASE certified technicians. Although they perform all manner of things related to automotive care, ATF has used its knowledge of transmissions and race cars to develop a line of specialized, purpose built, racing Powerglide transmissions.

ATF's Stage IV High Horsepower Powerglide Transmission.

Automatic Transmission Factory owner Jason Gatlin, in addition to building and tweaking some of the strongest transmissions in the country, serves as crewchief for champion drag racer Jim Blair. The team of Gatlin and Blair entered Florida’s massive drag racing scene with a “just win baby” mentality that has rewarded the team with several championships across a couple different classes. With Blair behind the wheel and Gatlin setting the car up, the duo learned what it took to make record setting runs. Along the way, Gatlin continued to sharpen his already impressive skills as one of the premier transmission builders in high performance circles.

How We Got Involved

When it came time to pick a transmission for our All Air Camaro project car, we wanted one that would work for serious drag racing and could be mounting behind any engine combination that we could hang in front of it. Blair and Gatlin’s success on the track was too hard to ignore, so we decided to go with ATF’s Stage 4 Powerglide.  The GM Powerglide transmission is a tried and true gearbox for the track with its simplicity and toughness.  The fact that the two speed gearbox only has to shift once down the track has made it a favorite with drivers. Gatlin and crew have taken this favorite slushbox to another level with their built in-house custom parts. We caught up with the very busy Gatlin as the crew was getting ready for the next racing season, to find out how ATF builds their very popular high horsepower stage 4 Powerglides.

"It all starts with reverse engineering," says Gatlin. The first step is measuring every dimension of the stock part and entering it into a 3D CAD program.

Where The Build Starts

Gatlin explained that the whole process of developing a new component, whether it is a single part or a complete assembly, “It all starts with reverse engineering. You have to take the original part and draw it out to size. I do all my work in a software program called Solidworks which gives us a complete picture of the part.” In using the 3D CAD software, Gatlin is able to produce 3D geometry that can be processed into machining specifications that can be sent directly to CNC machinery. The process allows Gatlin to produce and track the redesigned part from 3D geometry to the finished product without the potential for errors.

Gatlin draws all of his high performance parts, from turbo mounts to internal transmission parts, in a CAD program to evaluate them before ever making a prototype.

With the 3D geometry entered into the CAD program, Gatlin has an exact idea of how much material is needed for the part, which helps with purchasing the right amount of material. While measuring and entering the data into the CAD program may seem labor intensive, it actually helps the process by keeping the parts being manufactured at very tight tolerances while keeping the material inventory at an exact level. What that means to the customer is, “very high caliber components at a midrange price tag,” says Gatlin.

From Computer To Prototype

Once a part has been reverse engineered, Gatlin evaluates the component in computer simulation. Gatlin says “having the ability to draw the part in the CAD program and then draw a high performance part, or what I think a high performance part should look like, gives me the chance to see how they all fit together.  I have every part that comes in a Powerglide drawn in the CAD program. Clips, retainers, springs, I’ve drawn them all. From there I can do a sectional view of the transmission and see how all the parts lay together.” This gives Gatlin a chance to “electronically install” his high performance part in the transmission in the CAD program to see all of the tolerances and fitment of the part to ensure that it will all work together as an assembly.

Once the CAD-drawn part is checked for detail and fitment, Gatlin makes a prototype in ABS plastic of the new part.

If he’s satisfied with the computer views and simulations, Gatlin makes a prototype of the part in ABS plastic. Unlike several other types of modeling like wax modeling, ABS plastic provides a higher degree of detail. It can even be sanded, milled or painted. Having the capability of this type of modeling gives ATF the ability to catch errors or make design changes before an actual part is ever manufactured. The prototyped part is fitted and checked with the existing parts which shows any areas where additional engineering or milling work needs to done. After checking every aspect of the prototype, Gatlin orders the material to manufacture the part.

There is a point where Gatlin orders aftermarket parts instead of making his own. “I’m not looking to make something like transmission cases when there is enough of them out there already. As long as they meet our quality control checks, we’ll buy those type aftermarket parts. But other internal parts, where there is a chance to improve upon the stock or aftermarket parts, we’ll go through the design process and build our own.” Gatlin added, ” The Powerglide is pretty much our claim to fame, so we make pretty much everything for that transmission.”

When the bulk material arrives at the shop, the ATF crew swings into gear making new high performance parts.

From Plastic to High Performance Part

The materials are ordered based on which stage of transmission is being made. Each stage is rated by horsepower input to the transmission and higher horsepower increases the likelihood of more exotic materials being used or more friction and steel disks being used in the clutch pack assemblies. Gatlin illustrated that point by saying, “The more power that we go through, the larger diameter things are going to get, as far as shafts and that type of components.” In generic terms, higher horsepower requirements demand larger material blanks to manufacture the parts from.

When the raw material is delivered to the shop it is immediately sent to the band saw for sizing, then separated for individual component machining.

When the material is sorted, the machining begins. Plugging in the data from the CAD program, the HAAS machining centers or HAAS CNC lathes get to work machining the parts. The CNC machining center is capable of machine flywheels, flexplates, engine plates, engine brackets, valve bodies, valve body plates, drums, pistons and many other items. CNC machining is a complex process where the machine is programmed and then the material (usually a solid block of aluminum or steel) is secured to the table inside the machine. The machine’s table and cutting head move while the cutting head carves the part from the material. The cutting head can hold a multitude of interchangeable cutting tools. The tools are selected according to the instructions programmed into the machine. On the right side of the table is a 4th axis. This can be used to cut splines or rotation of a part while machining. CNC machining is extremely precise and can repeatedly produce identical parts within very tight tolerances of quality control.

ATF's CNC machining center is capable of making many of the precision components used in the high performance transmissions. ATF also uses the machine to manufacture specialized engine components and brackets.

ATF’s other computer controlled workhorse is the HAAS CNC Lathe which is used to machine valves, shafts, bushings, pistons and any object that is round. The material is spun with the spindle and the tools are used to profile the outside diameter. After all machining is completed, the part is cut off and caught in the parts catcher.

After all machining in the CNC lathe is completed, the part is cut off and caught in the parts catcher.

Valve Body

Gatlin is very particular about the valve bodies that he installs in his transmissions. According to Gatlin, “The valve body is the brains of the entire transmission. Our valve bodies are all made in house on CNC machines, as are our separator plates. We’ve tried a lot of different configurations and dyno tested every type of valve body on the market. We’ve found something that works and we’ve stuck to it. We believe we have the best one available.” All of the ATF transbrake Powerglides get the same valve body.  Gatlin explained that the operating pressure may be different but the valve bodies are all the Pro-Tree valve design. “If someone is drag racing, they want the best competitive edge. Instead of having multiple programs for different levels stored in the machines, we just give them the best. That’s what they want anyway,” said Gatlin.

A valve body gets ready for dyno testing.

The valve bodies are run on a special valve body dyno and the unit is hydraulically checked. The valve body dyno uses a hydraulic pump to simulate the pressure and flow inside the transmission. When testing the valve body on the dyno, ATF verifies that it will shift properly and deliver the correct pressures that the transmission requires. Quick pressure build up on the gauges and no visual leaks from the valve body are just a few of the quality checks that Gatlin and crew perform before the valve body can be installed onto the transmission. Initially, the body is pressured with 100 psi and the circuit is tested to see how much pressure is in the system. “This lets us check the integrity of the transmission. If we apply 100 psi to the system and only 80 psi is in the circuit, we have a 20 psi leak. We would have to find that leak and repair it before it ever gets installed into the transmission,” says Gatlin.

Gatlin builds every Powerglide transmission the same way; from the bottom up.

Building the Transmission

“We always start by doing what I call a ‘pre-assembly’,” says Gatlin. “I put the stack up on the drum and the piston, before I install the lip seal, all the steels and clutches and the snap ring to make sure it stacks up correctly. We do this dry stack up on the high speed drum and reverse clutches down at the bottom just to make sure that all the clearances are correct,” Gatlin added. In doing a pre-assembly, the crew at ATF can check if any additional machining needs to be done and a complete cleaning of the transmission case can be performed removing any machining shavings before final assembly.

When the clearances are entirely correct throughout the transmission, Gatlin begins the assembly. “In our ‘clean room’, we assemble everything in groups and lay the sub-assemblies out for final assembly,” says Gatlin. For the drum assembly, Gatlin installs the lip seals on the piston, puts the springs in and the snap ring on and then assembles the steels and clutches in the housing.

Machining an orifice for for higher performance.

Once the sub-assemblies are laid out, Gatlin begins the final assembly from the bottom up. “It’s much easier to make sure you have all your bases covered with the assembly if you have a procedure. I always work from the bottom up without skipping a step so that I know every piece is installed” he explained.

The valve body completed assembly.

Finishing and Checking

When everything internally is installed in the transmission case, the transmission is turned over and the valve body and shift lever are installed. “When we get the transmission completed, we perform an air test on it.  That lets us know that everything is operating within specs. We air test each passage which lets us know if the high gear clutch applies, the reverse gear clutch applies, and that there are no leaks,” said Gatlin. After the air test, the tail housing and transmission oil pan is installed and the entire assembly goes to the chassis dyno for final testing and shipping to the customer.

Our Project Car’s Transmission

Our project car All Air will be fitted with different powerplants throughout its life as a project vehicle, so we wanted a one shot transmission that would fit behind any motor that we could shoehorn into the engine bay. The ATF Powerglide Stage IV High Horsepower transmission fit the bill perfectly. Rated up to 2,5oo horsepower, this two speed Powerglide could handle anything that we would try to throw at it.

Features of the ATF Stage IV High Horsepower Powerglide:

• ATF Profiled, SFI Approved, J.W. Performance Transmissions Bellhousing
• ATF Prepped, SFI Approved, J.W. Performance Transmissions Case and Roller Tailhouse.
• Deep Aluminum Pan and Filter.
• 9310 Chromemoly 1.80 straight cut gear set and output
• 300M Turbo spline input shaft.
• Heavy duty (larger than stock) ATF-designed Stator Tube.
• New Teflon high gear drum bushing.
• 10 pack high gear drum.
• 10 clutch billet steel hub.
• Heavy duty adjusting pin.
• Dual ring billet servo piston.
• ATF billet servo covers.
• ATF dyno tested fluid release transbrake valve body.
• ATF modified front pump for more fluid transfer at low RPM.
• New Red friction band.
• New Red friction clutches.
• New steels.

Gatlin explained that transmissions with a higher horsepower rating generally have larger diameter internal components. A good example of how ATF accomplishes this is in their improved stator tube. The ATF stator tube is larger and can handle a higher horsepower engine or an engine with power adders by using stronger materials in a larger diameter and thicker walls in the tube.

The evolution of ATF's stator tube from a material blank on the left to the completed product on the right.

ATF's billet pump for Powerglides with stator tube installed.

Torque Converter

Torque converters don’t always get the attention that the rest of the drivetrain does, until something goes wrong. Once you’ve mounted a monster motor with a couple of turbos in the chassis, you can find out pretty quick that a strong converter is a really good thing. ”Strength is actually a side benefit of the new ATF converter,” says Gatlin.  ”The real trick part about our race converters is that they help multiply the engine’s torque output.  Also, higher stall speeds allow the engine to rev up into its powerband. For example, on a five speed manual equipped vehicle, it’s the equivalent of holding the clutch pedal to the floor while applying the accelerator pedal to get the RPM’s up, then releasing the clutch pedal.  A properly spec’d and built torque converter makes all the difference in the world for an automatic transmission equipped vehicle,” he added.

"CNC stator fins, precision cut on a CNC machine, help tighten up tolerances and efficiency," according to Gatlin.

Gatlin says that ATF is able to manufacture a stronger converter because they CNC all the individual components rather than fabricate them. “We use custom stators cut out of billet aluminum on CNC machines where a lot of other manufacturers build their stators out of fabricated steel parts that are made by hand and tig welded together. It’s impossible to get all the fins equal when you make each one by hand. With the CNC machine, all fins are created equal,” states Gatlin.

It’s clear that the ATF crew is proud of their level of precision. To illustrate that point, Gatlin said; “We try to get the converters to lock up as tight as we can and be as efficient as possible. The only way to accomplish that is to tighten up all of the tolerances from the end of the turbine blade tip to the stator blade tip. If you want a convertor that is a little looser for an all-motor car, you open up the gap a little bit but either way, precision is the key to making a great converter.”

Internal view of ATF's CNC machined torque converter.

Ballooning is a term you hear often in torque converters. We asked Gatlin what is ballooning and how ATF combats that problem in torque converters on cars with serious power adders; “Ballooning is outer case of the torque converter flexing. If you take a torque converter and lay it on a table and measure the height of the converter off of the table, that it’s static measurement. Now add 200 psi to the converter and remeasure the height. If it has gotten taller, the difference of the measurement is how much ballooning has taken place. A lot of companies will add plates to the case to make the metal a lot thicker or reinforce it. Because we are machining out our cases on the CNC machines, we are already making our cases thicker, so we don’t have to weld in plates or things to support the case.”

Gatlin went on to explain that with the levels of power being made these days, “Not only do people need a transmission that can handle it, they need a torque converter that can deal with the incredible amount of torque.” In the case of our project car, we took the advice of Gatlin and went with a custom ATF torque converter with a stall speed of 4,500 RPM. This would get us higher up into the powerband of our All Air motor and get us off the line quicker. You can read the project car update when we installed the ATF High Horsepower Stage IV Transmission and Custom Torque Converter by clicking here.

Moving Forward

With our ATF transmission and torque converter installed, we are moving forward to the next stage of building our project car for the track. We appreciate the time that Jason Gatlin spent with us explaining the ins and outs of the ATF method of building a bullet-proof Powerglide. Stay tuned as we get one step closer to completion and plumb the fuel system and get our cooling system upgraded with a sweet new trick water pump and radiator.  For those that love electrical systems, our All Air project car will be re-wired for speed from nose to tail, and you won’t want to miss that one.

]]> http://www.dragzine.com/project-cars/project-all-air/building-a-stout-powerglide-with-atf-speed/feed/ 1 http://www.dragzine.com/project-cars/project-666/project-666-receives-tcis-rugged-c4-transmission/?utm_source=rss&utm_medium=rss&utm_campaign=project-666-receives-tcis-rugged-c4-transmission http://www.dragzine.com/project-cars/project-666/project-666-receives-tcis-rugged-c4-transmission/#comments Fri, 11 Mar 2011 22:49:46 +0000 Andrew Wolf http://www.dragzine.com/?p=45436
In a recent update on our Project 666 Fox-body Ford Mustang from here at the powerTV garage, we provided a general look at and installation of a whole set of new high performance drivetrain components from TCI Automotive, including an 8-inch Pro-X torque converter, an Outlaw shifter, flexplate, and other go-fast parts to make our ride really tick. But, at the heart of it all is TCI’s C4 automatic transmission, which is based on the original and popular OEM C4 transmission produced by Ford Motor Company for more than two decades. The race-intended TCI C4 improves upon the reliability and durability that the C4 has long been known for, which is just what we’re looking for to mate with our naturally-aspirated, 408-inch Windsor motor producing nearly 575 horsepower. We just know that our fox body had some 10′s in it, and with a previous best of 11.91 at just over a buck-20, we’re definitely in the hunt for much lower numbers.

In this installment on Project 666, we’ll take a more in-depth look at the venerable C4 that TCI has redesigned with the power-user in mind, along with the installation of the transmission, torque converter and other related components. As well, the moment we’ve all been waiting for finally comes, as 666 hits the track in Fontana with some impressive results.

Built Ford Tough

A cutaway view of an OEM Ford C4 transmission.

Ford’s longstanding C4 three-speed automatic transmission went into production in 1964 and was the first all-Ford designed and manufactured automatic transmission. And when it comes to strength, the 1970 and newer C4′s are the way to go with their large input shaft. The 26-spline and .839-inch shaft make for a unit that can handle a lot of punishment; sometimes upwards of 600 horsepower when utilizing hardened, aftermarket input shafts and splines. In addition, the cases made after 1970 use a different mounting design from previous versions as the bellhousing bolts up to the case rather than the front pump, equating to an additional level of strength for demanding applications.

The C4 underwent several refinements around 1970 while being employed in a long list of Ford, Lincoln, and Mercury vehicles, and to this day is still the simplest and most reliable automatic transmission that Ford has ever produced.

Despite the end of it's production, however, the C4 remains popular with the drag racing and hot rodding communities for it's simplicity and durability, and remains a popular choice today by a multitude of later model Mustang drag racers.

Ford’s C4 was replaced in 1982 by the C5, and despite the end of it’s production, remains popular with the drag racing and hot rodding communities for it’s simplicity and durability. In fact, a multitude of late-model Mustang racers even choose the C4 over GM’s venerable two-speed Power Glide for racing purposes. And so it should come as no surprise why we opted for TCI’s improved and enhanced version of the C4 to help propel our Project 666 Mustang.

Taking The C4 One Step Further

The external transbrake solenoid and bracket are installed on the transmission. By being installed outside of the transmission case, the solenoid is able to cool much quicker than an internal design when; something very important if you're a drag racer in a round-robin situation.

While the Ford C4 is widely regarded as an exceptional transmission with the utmost in durability, it is not, however, generally up to the task of handling a high amount of horsepower or standing the test of grueling racing applications. And that’s where TCI takes a great starting point with the Ford C4 transmission, and conformed their own internal design and components to make this one stellar racing transmission that’s used by racers far and wide.

TCI’s C4 is a standard transbrake, three-speed automatic transmission, sporting the low-drag, six-pinion planetary kit that still uses the stock ratio but has bearings all the way through. A late-model, 26-spline case filled setup, it also has a reinforced forward gear drum, a billet intermediate servo assembly, 300M input shaft, a deep aluminum pan, and Red Eagle clutches. It should be noted that these features are all standard equipment on this model transmission.

The planetary set sports bearings all the way through, decreasing the amount of drag that ultimately robs your engine of horsepower.

This transmission is based upon a factory C4 transmission case, and designed and intended for use in racing applications. “This particular transmission, with many of the features that is incorporates, isn’t something that we’d suggest be driven on the street. It could be done periodically, but it isn’t something you’d want to put in a vehicle that you’re going to drive often,” said Scott Miller of TCI.

The low-drag, six-pinion planetary set is installed in the transmission case. The use of bearings in the gear set creates less drag than the thrust washer design used in the factory C4 transmissions.

The planetary set, which as mentioned, sports bearings all the way through, helps to cut down on drag that robs valuable horsepower; something that is always crucial in keeping at a minimum after spending thousands of dollars to create said horsepower, only to give it away. Explained Miller, “Ford transmissions – the C4 and C6 – are both real power robbers. They draw a lot of horsepower from the motor because the planetaries are heavier and run on thrust washers all the way through. So that creates more drag, pulling horsepower from the motor.”

The C4 – TCI’s Way

TCI has given the internal components of the C4 a complete overhaul, creating a design that promotes less drag and increased durability.

The design that TCI has implemented decreases the amount of drag considerably, pulling in the neighborhood of 18-20 horsepower, down from what is commonly around 30 horsepower in high gear. And being a Ford transmission where it would be commonplace to find it bolted behind a small block engine that on the average doesn’t typically make large amounts of excess horsepower, that 10-12 horsepower becomes quite a difference.

The six-pinion planetaries are created entirely in-house by modifying the factory gear assemblies to add in the extra gears. From the factory, the C4 sports a three-pinion planetary, and thus, is doubled through TCI’s process. The three-pinion planetary setup in the factory transmission is notoriously a weak link, and by increasing it’s size, the overall strength of the planetary assembly is vastly improved.

The deep, crafted aluminum pan outfitted underneath the TCI C4 holds an extra quart of fluid as compared to the factory unit, preventing the chance of fluid starvation, especially in high-RPM applications. The thick, aluminum construction is also much tougher than the OEM pan.

The deep, crafted aluminum pan outfitted underneath the TCI C4 holds an extra quart of fluid as compared to the factory unit, preventing the chance of fluid starvation, especially in high-RPM applications. This is a very common occurrence in higher RPM engine combinations, where the fluid cannot be pumped quick enough to get it back into the pan quick enough to keep the filter submerged in the fluid. And in being constructed with strong, thick, aluminum, it provides some additional strength and rigidity to the case.

The pro-tree style valve body in the C4 uses a reverse pattern setup with an external solenoid, meaning the transbrake must be engaged in reverse in order for the car to back up.

The transbrake valve body is designed and manufactured in-house at TCI and is a pro-tree style unit that uses a reverse pattern setup with an external solenoid. A “pro-tree” valve body means that the transbrake must be engaged in reverse in order for the car to back up.

The entire TCI C4 transmission, like every product that TCI manufactures, goes through a rigorous testing procedure to check for quality and function. This process is done in three separate stages. First, the valve body goes through it’s own special dynamometer, the transmission is then hydraulically tested on another dyno, and finally, the valve body is bolted on and pan installed and the entire unit is put through its paces on yet another dyno that returns results with figures such as the pressures for each gear, the cooler flow in each gear, and other detailed information.

700 Horsepower? No Problem

These improved elements of the trusty C4 by TCI make this a very solid unit for use in higher horsepower applications, and a great fit for our Project 666 Mustang. “This transmission could be put behind a 750 horsepower application with no problems whatsoever. As well, there are some custom things that we could do to increase the pressures to make it handle even more horsepower, if needed. Part-wise, it’s just fine, but when you’re increasing the horsepower, it’s a good idea to bump the line pressure up a little bit more,” says Miller.

In addition to the C4 transmission itself, we will be outfitting our Project 666 with a host of other add-on accessories from TCI to get the best performance and ease of use out of our new drivetrain.

Rounding Out 666’s Driveline

The TCI Transmission Cooler kit is designed specifically for racing applications and is the largest that TCI offers.

First, we have the C4 SFI-certified bell housing, made of a tough 6061 alloy aluminum that will bolt right up to the C4 without any modifications. The C4 transmission doesn’t typically come with a bellhousing included in the kit, because as a detachable component, most people commonly have their own. The bellhousing, along with the Transmission Cooler Kit (Part# 823800) come highly suggested by TCI, but not a mandatory add-on. The Performance Cooler is a 26,000 GVW cooler designed specifically for racing applications, and is the largest that TCI manufactures and it outfitted with a #6 AN female fitting on it.

Unlike other flexplates on the market that have the ring gear welded on one side, TCI has taken the extra step of performing the welds on both sides of this thicker-than-stock piece.

TCI’s SFI-approved flexplate features extra welds all the way around both sides. Most flexplates on the market have the ring gear that is welded on one side, but TCI has taken the extra step of performing the welds on both sides of this thicker-than-stock piece. 666 will also benefit from the use of a RollStop Solenoid (Part number 861100) to perform burnouts like the professionals. By using the RollStop, you simply pump up the brake pressure, apply the RollStop, and release the brake pedal, which keeps the front brakes applied during the burnout procedure. According to Miller, this unit is universally designed to work with ay type of breaking system, and can withstand pressures of 3,000 psi while only drawing one amp of current.

For our purposes, we chose TCI's Outlaw Shifter that features an integrated two-button handle: one for the transbrake and the other for the line lock.

TCI offers a handful of options for shifters that all comes down to personal preference, and we chose to go with the Outlaw Shifter that features an integrated two-button handle: one for the transbrake and the other for the line lock. For those that prefer to do without the button setup, an Outlaw Shifter minus that feature is also available. Along with the shifter, we’ll be utilizing TCI’s three-speed Rev Pattern Thunder Stick/Outlaw Gate Plate that essentially makes the Outlaw Shifter a reverse pattern setup for the C4 transmission, which uses a reverse pattern valve body.

We’ll be outfitting our C4 with TCI’s SFI-approved Trans-Shield, made from 6061 aluminum that bolts right up without any modifications. Also, we’ll be running our C4 with TCI’s Max Shift ATF fluid, which is available in four different blends to cover most automatic transmissions. Said Miller “it’s not a Dextron-based fluid, but it has additives in it that makes it run a lot cooler than other fluids without breaking down as quickly and easily.”

Converting The C4

Our C4 will be mated up to TCI's eight-inch, steel stator, weld-together C4 converter designed for full race applications, which is good for about 875 to 900 horsepower

And finally, our drivetrain would be virtually useless without a high performance torque converter mated to the C4 transmission to transfer the power to the rear tires. And so we’ve installed TCI’s eight-inch, steel stator, weld-together converter. This converter is designed for full race applications that Miller states is good for a maximum of about 875 to 900 horsepower, as it will stall too high with any more horsepower than that.

Nowadays, racers are going with much larger converters, such as the 9 and 10-inch Pro-X line, because of the amount of horsepower they’re producing. However, for a combination such as ours, the smaller converter is a perfect fit for the level of horsepower that we’re planning to produce, as a larger model would simply bottleneck our engine on the racetrack. Said Miller, “In this type of application, the eight-inch converter is going to perform better, because with the higher horsepower rated converter, it’s going to slip too much on the top end, cutting down on elapsed time and mile per hour.”

TCI redesigned C4, outfitted with stronger and higher performing components from front to back provides the peace of mind that transmission troubles should be the least of our worries with Project 666.

Trip to Fontana with High 10s on the Mind

Our trip to the track began surprising early, with a departure time of six o’clock in the morning, in order to arrive at the track in time for a prime pit spot. As it turned out, we ended up a 1/4 mile from the staging area. We used the two mile asphalt circle track that is parallel to the pit area as a point of reference in measuring the distance. This is the same oval track that NASCAR holds their annual Fontana races on.

A quick check of fluids, tire pressures and window cleaning, and we were set. No sooner than we got James stuffed into the driver’s seat, the call came over the public address system for cars to start moving to the staging area.

Our initial choice to enter in the Sportsman class turned out to be a mistake and we chose to move up into the Pro class. On the first run we left at 3,500 RPM of the trans brake, and our project car rebounded with a 1.49 sixty foot and a 7.17 @ 94.23 mph eighth mile where he lifted and coasted out the rest of the track to a 11.92 @ 87.93 mph. James reported an issue with the shifter possibly being mis-adjusted. One the second pass of the day, 666 carried the wheels with a 1.43 sixty foot and a 7.06 @ 94.35 mph eighth mile time and rounded out the quarter mile with a 11.17 @ 117.70 mph pass. We did notice during the run, each gear change resulted in a loud bang through the exhaust system.

Another five minute walk back to the trailer and our worst fears were confirmed. The pop in the exhaust was substantial and we needed to track down the source. After listening to the engine, we determined that there was a problem with an leaky exhaust gasket that was drawing fresh air into the exhaust flow.

Another five minute walk to the staging area where we met James waiting to move into the burnout box. James drew the left hand lane, where he started on the first run of the day. The car launched much harder than the previous runs and the gears shifted smoothly resulting in a breakout run. We had dialed a 10.80 and ran a 10.56 @ 116.94 mph while on the rev limiter the last 150 feet, due to the lack of rear gear. With the proper gearing and being able to stay in it the entire duration of the track, 10.30s would have been achieved.  The last five minute walk was a bitter sweet feeling because of the nice run but the reality of breaking out and going home meant the end of the day.

Our three time slips throughout the day with car number 7555. Click the picture above for a larger version.

Because our plan for this project was to take the route of an automatic transmission, one of our primary needs and objectives was outfitting the car with a transmission that we knew would stand up to the demands of the horsepower from our venerable 408, and TCI’s C4 is exactly that.

It combines all the great attributes that Ford fanatics have come to know and love, with the increased durability and performance that has made TCI among the leaders in the industry. And coupled with other quality driveline components from their catalog, we rested assured that once we hit the track, transmission troubles would be the least of our worries. With plenty more performance on the table, we’re not quite done with this Fox just yet, so keep it here for more updates as we pound the quarter mile in our pursuit of the mid nine-second zone.

Torque converters are the component that made the modern automatic transmission possible, transferring power from the engine to the rest of the drivetrain without the use of a clutch. Even though we’ve all used them, few of us understand what’s actually going on inside or how they’re built. To answer those questions, we talked to TCI, one of the country’s most popular manufacturers of performance converters, and they were gracious enough to walk us through how converters are made, and how they do their job.

Before we spoke with the professionals, we did some research of our own. We discovered that although boat-loads of research and design have been dumped into the torque converter since it’s creation, it originally began as an option in luxury daily drivers in the late 1940’s.

Buick revolutionized the automobile industry by developing the first fully automatic transmission in 1948.

Torque converters have been around for decades. Originally introduced in 1948 with Buick’s 2-speed Dyna-Flow transmission, the torque converter helped make the transmission fully automatic by eliminating the clutch necessary for manual transmissions. What makes torque converters unique is the transfer of power from the engine to the transmission with fluid being the only connecting factor, allowing the engine to idle without the threat of stalling. Along with preventing engine stall, the converter helps improve performance by nearly doubling the torque of the engine which offers a higher degree of acceleration. Although OEM torque converters are continuously improving, the high performance industry will always be ahead of the game by offering more overall power, better acceleration, and improved fuel economy for not only custom engine applications, but stock packages as well.

Though it might seem strange, thinking of a torque converter as a jelly-filled donut helps to visualize how it works.

What’s Going on Inside a Converter

In order to feel confident with selecting your high performance torque converter, you must first have an understanding of what makes them work. We know that this “jelly-filled donut” bolts up to the flex plate, and we know that the input shaft of the transmission slips into the back side. What we don’t know is actually the most crucial part: the inner workings. The casing that bolts up to the engine has a set of specially designed fins fixed to the inside. This part of the converter is known as the impeller which spins at the same rate as the crankshaft. When the impeller spins, centrifugal force pushes the transmission fluid through the angled fins toward the outside of the casing. Once the fluid reaches the outside of the casing, it hits the reflected angles at the top of the turbine, which is splined to the input shaft of the transmission, causing it to turn the transmission input shaft. The fluid is then directed back toward the center of the housing where the process repeats.

The stator keeps the fluid flowing smoothly inside the converter without turbulence. This increases performance and fuel efficiency.

The Stator: Keeping it Flowing Smoothly

The whirlpool action inside the torque converter is controlled by the stator. The stator sits on a one-way clutch in between the two rotating vanes. The extreme angled fins redirect the fluid from the turbine before it returns to the impeller. This action improves performance and fuel efficiency greatly. Although the stator is key in the torque converter’s job during idle and acceleration, it plays a smaller and smaller role as the torque converter approaches ‘lock-up’ speed where the two impellers are spinning at nearly the same rate.

With a basic understanding of the internal components under our belt, we turned to one of the world’s most popular performance torque converter manufacturers, TCI Performance in Ashland, Mississippi, to get a better grasp on how all those components can be tuned to get more power to the pavement.

TCI Automotive is based in Rural Mississippi, but they are well known all over the world.

Our insider’s look at TCI’s shop gave us a perspective most people outside the business never get. While factory converters are built by the thousands, all exactly alike, TCI takes pride in doing it by hand, one at a time. “We don’t do an assembly line. We have one or two builders, and all they do is assemble the torque converters,” TCI engineer Scott Miller explained. “They set the clearances, they set the fin angle, so it keeps everything uniform when you don’t have a bunch of people doing it.”

Unless you build them, you rarely get to see what's inside a torque converter.

Turning a Stock Core into a Aftermarket Monster

“Essentially, we start out with a stock core and we cut it open,” explained Miller. “We then send the top (impeller) and turbine out to be furnace brazed, which basically strengthens the fins and welds them solid,” he continued. “When those pieces come back, we install new hubs, bearing ride plates, heat-treated turbine splines, and a modified stator with new sprags and sprag races, and we build the cover with a new pilot and mounting pads to bolt to the flex plate.”

Once everything is installed in the refurbished converter, the unit is ready for inspection to ensure it’s all correct before it is sealed and tested.

The front cover will be welded to the impeller in the final step of assembly.

Quality control is what sets TCI apart from the competition, so it’s no surprise that so much time and effort goes into the inspection process. “Our technicians have a check-off sheet when the converter is being built. They record the hub size, turbine clearance, sprag, and the pilot size during assembly,” said Miller. “From there, the converter goes to an inspector in the Quality Control department. They inspect every converter and verify that the part number stamped on the converter matches the fin angle and stator configuration.” Once the inspector signs off the inspection card, the two halves are ready to be welded together.

One of the many tests a converter must pass before it gets TCI's approval is for runout.

After the converter is fused into a single whole, the final stage of inspection can occur. The converter is submerged in water and pressurized to ensure that it’s completely sealed. The converter is then balanced and the end play is double checked. A transmission input shaft is then inserted in the hub to ensure proper fitment. Once all of the tests are passed, the converter shell is coated with a heat dissipating paint and it’s packaged for shipment. Miller stated, “Depending on the model, sometimes we can have a converter built within that afternoon. Our average turnaround time is about one or two days.” Some of TCI’s wildest builds are for 200 mph+ customers like Todd Berry, John Kolivas, and Jason Lee.

The turbine rides inside the front cover and interacts with the impeller to provide power to the transmission.

Changing Stall Speed

When asked how a torque converter is customized for each application, Scott Miller informed us that the most important factor is the converter’s ‘stall speed.’ “There are a few different ways to change stall speeds. You can change the angle of the impeller fins by giving them a positive angle to lower the stall speed or a negative angle to increase it,” Miller stated. “You can also change the stator in the converter. Different stators have different fin angles and different amounts of blades which change the way the fluid flows through the converter. You can also change the clearance between the turbine and the impeller. If you increase the clearance, it lets it slip more and if you tighten it up, it lets it lock up, which decreases the stall speed,” Miller explained.

powerTV Projects use TCI Converters too

Many of our Dragzine.com and StreetLegalTV.com followers know that we used TCI in ‘Project 666,’ a Fox Body with a 408ci crate engine. We strapped their custom converter behind our power plant, along with a TCI C4 with an upgraded case. The small block Ford pushed out an amazing 500 horsepower on the engine alone. 666’s first time at the track was at Irwindale where it ran some 11-second soft hit passes.

Putting together the right converter for your application is TCI's primary goal.

Of course, in a sport where zero-to-hero is measured in thousandths of a second, there is a lot more to getting the right converter than just stall speed. The good thing is that TCI is there to help, and with the right information about your suspension and chassis, tires, transmission, and engine, their staff can design a torque converter that will shed seconds and add MPH. You don’t have to be an automatic transmission expert – that’s their job – but now you know the right questions to ask, and have the background information to understand a little bit of what they’re talking about.

You are at the dragstrip getting ready for a run. The revs come up on the chip, lights go green, the car moves about six inches while the motor pegs the rev limiter. A few minutes later, there is a jack under the rear end and four guys pushing it back from the front end. You sir, have just experienced a drivetrain failure. Though this is a relatively tame form of drivetrain failure; snapping axles mid-track never has a happy ending.

You can have all the power in the world, but if you cannot transmit that power to the rear tires properly, it doesn’t do you any good. This includes not only a good differential, but also bullet proof housing and a strong set of axles to support the package. When it came to putting a rear end into our Project MaxStreet Chevy II, we turned to Moser Engineering for that reliability, including their new Wavetrac differential.

Our 1966 Chevy II is receiving a low compression, Edelbrock/Musi 555ci big block Chevy with an F2 ProCharger.  With 850 horsepower to the rear tires on low boost, we needed a rear end that could handle brutal power.  But this isn’t a drag strip only Nova, it is a designed for all facets of asphalt motorsports, including a lot of street driving.  This is where the new Wavetrac differential is going to help us, by supplying the power evenly to the rear tires regardless if it’s on the dragstrip or road course.  Additionally, Moser’s ability to install our custom Detroit Speed four-link brackets during manufacturing made our job even easier.

Ford 9-inch Rear End – Found More In Chevys

What most don’t know is that the Ford 9-inch was first introduced in 1957. Many features like the drop-out center section design made it easy to service. Though the first variants were not as strong as its successors; the originals featured tubes welded to the center section with no supports. As the years progressed, triangulated housings and large-tube axle bearing ends were some of the benefits added to the housings.

As any product becomes popular, an aftermarket demand is born from it. Reinforced housings, gear ratios, a wide range of axle spline offerings and differentials made it easy for people to mix and match to their heart’s content.

The Moser 9-inch came with our Detroit Speed brackets welded on and powder coated. We simply had to install the center section, axles, and parking brake assembly

Building our Moser 9-inch for Project MaxStreet

Project MaxStreet is a 1966 Chevy II that is acquiring the modified 555 Edelbrock/Musi crate engine that was in Project Grandma. Now it is being fitted with low compression JE pistons, an F2 ProCharger, and a FAST XFI fuel injection system. We look to make around 850 horsepower to the rear tires while maintaining total street reliability. That means we needed a rear end that can perform perfectly on the street and drag strip. That means there is medley of situations that we need this Chevy II to perform in. It isn’t going to be as easy as throwing a spool in the housing and calling it a day. We needed a functional differential and a strong supporting package, but nothing off the wall.

When it came to designing the rear end that is going into MaxStreet, we turned to the “Build to Order” section of Moser’s website. We went with their 9-inch stamped housing that is constructed of seamless steel tubing. The seamless steel construction retains rigidity throughout the rear end by not having welded sections, or a flat piece of metal that has been rolled into a circle and welded.

Moser can custom weld any brackets during the manufacturing process

The Ability to Install Any Custom Rear End Brackets With Moser

Part of the construction process is adding the proper mounts to the rear end. Since we had our Detroit Speed QuadraLink recently installed, we opted to send the rear end brackets to Moser so they could weld them on while building the housing.  “We work with a lot of major chassis parts suppliers, like Detroit Speed, so if a customer wants to send their brackets, we can weld them to the housing without a problem,” said Jeff Anderson of Moser.  “We do stock all popular OEM-type brackets. Those brackets are thicker and feature reinforcements that you won’t find on a direct OEM piece.”

The first course of action is to install the studs into the housing and put the gasket in place. After this, the center section drops in place.

Detroit Speed includes a diagram with the kit that tells the angle and spacing of the brackets on the rear end, all we had to do was fax the paper to Moser. Additionally, we welded in a pair of Detroit Speed’s Deep Tub wheel tubs that gave us an additional 2.5-inches of clearance for larger tires. With the tubs done, we fitted the 17×11” Billet Specialties Street Lites that are wrapped in 315/35/17 Mickey Thompson drag radials into the tubs. Without the rear end in it, we measured from the pad face of the rim on both sides and gave Moser a measurement of 52-inches.

Axle and Center Section…Selection

Moser recommended their custom alloy 35-spline axles with a standard Chevy 5 x 4.75” bolt pattern. This is the largest spline count you can get from Moser without going to a spool. A larger spline count allows for a larger root diameter, the same reason that fine thread bolts are stronger than the same size coarse thread bolt when placed in tension. Fine splines and high strength threads are usually rolled in, a forging operation that compresses the metal, making the surface dense. Cut splines break up the grain patterns in the metal weakening the area rather than strengthening it.

The axles come with the bearings already pressed on. The bearing sits into the housing end and is held in place by a retaining plate. If you have the parking brake option, the axle must be slid through the brake assembly and then installed into the housing end.

Our center section came fully assembled with a bulletproof nodular iron case, Wavetrac differential, yoke, as well as the ring and pinion. The nodular iron case is a heat-treated forging that is more cost effective (though a bit heavier) than their aluminum case offerings. The build to order rear ends also come complete with all bearings, hardware, and gaskets – with mild assembly required. We even went with the silver powder coat option for a superb finish.

Our Ford 9-inch Specs:

• 35-spline axles with a 5 x 4.75-inch spacing
• 52” long (with brakes) stamped steel housing
• Nodular iron center section, fully assembled
• Wavetrac differential
• Fill and drain plugs
• Custom welded 4-link brackets from Detroit Speed
• Sealed ball bearings
• Integrated parking brake option

Moser’s new Wavetrac Differential is Designed with Handling in Mind

One of the known shortcomings of a typical torque biasing differential is its loss of drive under zero or near-zero torque conditions. The Wavetrac is the latest and greatest in differentials from Moser that is designed to help you over come those “one wheel peel” problems.  “The big advantage of the Wavetrac is how well it performs in light to partial throttle conditions,” explained Anderson.  “Say you have a truck that has one wheel off the ground, the Wavetrac will help you get out of that situation safely without having to mash the throttle. You can also customize the Wavetrac to suit your driving or racing needs.”

The Wavetrac differential is easy to disassemble and repair, while using minimal parts inside the differential. The Wavetrac uses converging/diverging wave profiles that are placed on one side gear and its mating preload hub. As the two side gears rotate relative to each other, each wave surface climbs the other, causing them to move apart.

The Wavetrac uses converging/diverging wave profiles that are placed on one side gear and its mating preload hub. As the two side gears rotate relative to each other, each wave surface climbs the other, causing them to move apart. This imparts an increased normal force through the side gears, increasing the bias ratio as a function of load. This increase occurs automatically only when conditions find it necessary, and it reverts back to its nominal bias ratio quickly and seamlessly, maintaining optimal driveability and performance at all times. It’s like having two differentials in one: you get the benefit of a higher bias ratio when needed without detriment to the car’s handling.

The Wavetrac differential is currently offered in GM 12-bolt and Ford 9-inch applications with a Ford 8.8-inch application in the works.

Assembling the Moser 9-inch Rear End

Installation was simple and straightforward. First we installed the studs that hold the center section into the housing. After that, we moved to pressing the bearings and seals into the axle housing. The nodular center section installs directly onto the studs with the supplied gasket.

Since we planned to drive the Chevy II on the street, we opted for Moser’s parking brake assembly, which must be slid over the end of the axles before installing the axles. Once the axles are installed into the housing, the retaining plates then secure the axle and parking brake assembly to the housing.

Assembly is very easy with the installation of the center section and axles being the only real task.

With the parking brake assembly finished, we began installing the Moser 9-inch onto the Detroit Speed four-link. The brackets we supplied to Moser lined up perfectly and it was as simple as installing the four-links, panhard, and shocks.

Building a rear end that has the ability to handle all the power you plan to throw at it is paramount in any vehicle build.  Moser made the process easy, as we were able to send over our custom housing width to accommodate our mini tubs.  Additionally, Moser was able to install our Detroit Speed QuadraLink brackets during the manufacturing process, which was a big help.  Lastly, there is no doubt the Wavetrac’s converging/diverging wave profile technology will keep the traction to our rear wheels, regardless if we are at the dragstrip or road course.

The completed rear end installed with the Detroit Speed four-link mated up perfectly.

In the early 1980′s at the ripe age of 12, Marty Chance began working for his father Neal at his shop pulling transmissions out of cars and performing rebuilds. By 13, he was disassembling transmissions, and a year later, full-on builds. Once in high school, Marty began to tinker with torque converters, and following their father’s purchase of a lathe at the convincing of brother Mitch, began dissecting and learning the in’s and out’s of converters in the backroom of his father’s shop. And thus, Neal Chance Racing Converters, one of the most well respected converter manufacturers in the world, was born.

“My dad and brother were playing with torque converters and we all got to toying around with them and so I guess you could say they got the whole thing started, but I took off with it and that’s how it ended up. I was a one-man show in the back of my dads shop, and it just grew from there. I was doing this full-time by the time I was a senior in high school,” explained Marty Chance.

A torque converter turbine is loaded into a CNC machine.

A Look Inside Design and Manufacturing

Like anything, the design of a racing converter begins with a theory based from experience. That concept can then be transferred to 3D modeling software and from there it’s on its way to becoming a reality. Neal Chance engineers – who design everything in-house – utilize many of the most sophisticated CAD/CAM programs on the market, and through the use of software, can fully test and determine the functionality of a converter design before a prototype is even conceived. “It’s through this sort of engineering and testing that we’ve been able to take converter technology to the next level,” said Chance.

When a steel converter is built, it begins with the use of a donor turbine and pump impeller. The fin angles are set on the various sizes of pump impellers to a specific degree and then tack welded in place and put through the process of furnace brazing – a process where a filler metal is heated above and distributed between two or more close-fitting parts. Once complete, all of the pressure points on the pump impeller and turbine impeller are hand heli-arc welded. Each of the 28 blades – or “vanes” – are hand-welded in six different places. It is this process that makes the fins virtually indestructible.

Neal Chance engineers design everything in-house using sophisticated CAD/CAM software. Once a concept has been designed and throughly tested, it is plugged into a five-axis CNC machine, where the components that make up a racing converter are finely carved into the desired result.

After all of the welding is done on the pump impeller, the center is then cut out of it for what is known as the hub insert. The entire center of the converter is cut out so that the bearing pedestal on the inside and balloon plate on the outside are one solid piece. This design eliminates the air gap that exists on a normal balloon-plated converter.

Likewise, the turbine impeller, following the welding and brazing process, has a custom turbine hub installed that’s made from a heat-treated chromoly material and heli-arc welded on the inside and mig-welded on the outside. The impeller is then pre-machined to ensure that the body of the turbine is running true. The turbine is then face-cut so that the edge of the fins are parallel with the bearing surfaces on the turbine hub to make everything run true. Once the turbine has been machined, it is then balanced much as are the rest of the components in the converter are before completion. “We balance all of the internal components separately because they rotate independently of the exterior shell. Balanced components take less power to turn, and in taking less power to turn, that means more horsepower to the rear tires.”

On the pump side of a converter, after the installation of the hub insert, it also goes through a pre-machining process in which the exterior of the case is checked, the hub insert trued, and the inside bearing surfaces and fins are machined until they are in parallel. The pump is then a finished product, ready for assembly.

The stator, a component that it is interposed between the pump and turbine to alter flow of oil returning from the turbine to the pump, is offered in both billet and fabricated varieties depending on the size of the converter. The billet stator is fully designed on the computer and created by a five-axis CNC machine.

A Stator comes to life on the five axis CNC machine.

The final component is the drive cover, which is the component that bolts to the flexplate. All of the drive covers at Neal Chance are made in-house from billet material. A drive cover begins life as a 100-pound chunk of billet steel material that goes through a lathe and five CNC processes to create the final product. A Neal chance drive cover uniquely features two extra holes on the converter pad so that if a mid-plate is ever added, you can simply add a bolt-on pad extension the same thickness as the mid-plate, bolted on using countersunk screws. Thus, you can swap the converter between vehicle makes, making it a very versatile unit. “Between all of our innovations, we’ve strived to bring the racers a converter that is less dependent on the converter manufacturer. In other words, I’ve taken myself out of the equation,” said Chance.