Hardcore Testing: 4th Gen Camaro With A TCI Bolt-Together Converter

Generally when someone talks about “best bang-for-the-buck,” they are talking about a part that has a price tag in the four digit range and may get you a tenth or two-tenths on the track. So, anytime we hear “best bang-for-the-buck,” we get our hackles up and one hand automatically reaches back to cover the wallet. This time our “big bang” theory took on a different twist.

We were alarmed when the folks at TCI Automotive started telling us about their new bolt-together torque converter for 4L60E transmissions. “You’re not going to find anything, dollar for dollar, that will give you that kind of bang for the buck,” said Chris Douglas of COMP Performance Group.

While it is true that one of the most economical improvements you can make in an automatic transmission performance car is a high-stall converter, we wanted to see for ourselves how much difference the new TCI bolt-together converter really made. Follow along as we install and dragstrip test TCI’s bolt-together converter on a fourth generation Camaro.

We chose this 2001 Camaro SS for our testing because it is a great representation of the vehicles that came equipped with the GM 4L60E transmission.

Setting The Benchmark

Our first task was to find a vehicle with a 4L60E transmission, a stock torque converter and an owner that wanted to push the limits a little bit. Fortunately we found Mike Sommer and his 2001 Camaro SS, that had the exact combination we were looking for.

The victory red Camaro was prepped with some decent upgrades like cross drilled and slotted rotors, a cold air intake, and aftermarket exhaust system. It was a decent representation of a fairly stock Camaro SS that can be found on any street in any town.

We set an initial track date of September 10, 2014, and had Mike make several runs down the track so we could get a decent average set of numbers to establish a benchmark. Getting an accurate baseline number was the most critical part of the test so that we would have a valid measuring stick on the “bang-for-buck” barometer.

Track Testing With Stock Converter

  • 60ft: 1.96
  • 1/8 mile: 8.46
  • MPH: 84.52

We established a decent baseline to work from with several runs down the track.

TCI Automotive’s Bolt-Together Torque Converter

The fourth generation Camaros were pretty fast from the factory but it’s no secret that aftermarket parts can make them even quicker. It’s a well known and accepted fact that 4L60E equipped vehicles can be instantly improved with a high stall torque converter.

One of the problems with many of the traditional lockup torque converters is the hard impact loading and associated shudder and shake at takeoff. This loading has made many vehicles unpleasant to drive on city streets and highways, relegating the car to track service only unless a converter swap was performed. According to TCI, their new patent pending sprung hub design absorbs that hard impact loading with none of the shudder or shake of traditional lockup converters, which makes it a perfect piece for combination street/strip cars.

This cutaway shows all the details of the TCI bolt-together lockup converter. This is NOT your Daddy’s stock converter.

Here’s the low-down on the new converter in a nutshell:

  • Two-piece billet case
  • Woven carbon triple disc lockup clutch
  • Higher stall speed than stock
  • TIG welded impeller
  • Fully furnace braised turbine
  • 50-spline clutch hub with integrated valving
  • Patent pending apply pressure technology
  • Ideal for WOT lockup applications
  • Does not require ECU tuning

We didn't wait very long after the track testing to get the Camaro back to the shop and swap out the torque converters. It would take us a couple of months to get a track date, film crew, driver, and all the other pieces in place to do followup testing.

We didn’t wait very long after the track testing to get the Camaro back to the shop and swap out the torque converters. It would take us a couple of months to get a track date, film crew, driver, and all the other pieces in place to do followup testing.

“Being a bolt-together unit, it makes changes easier to the end user as they upgrade their engine…we have a wide range of tops and stators that will allow them to change the stall themselves. This prevents a lot of down time.” –Scott Miller, TCI

The billet case makes this unit stronger than a stock converter. When you couple that with the heavy duty 50-spline clutch hub, which incorporates the new sprung design, along with the triple disc lockup clutch–which is a big deal for a lockup converter–then you have a torque converter that allows for harder launches and quicker ETs. The beauty of this design is that it does not sacrifice street manners or lockup capability, and it ultimately improves the life of the transmission. Let’s not forget that it is a bolt-together design as well.

“Being a bolt-together unit, it makes changes easier to the end user as they upgrade their engine,” said TCI’s Scott Miller. “With the bolt-together, we have a wide range of tops and stators that will allow them to change the stall themselves. This prevents a lot of down time.”

GM 4L60E Bolt-Together Torque Converter Part Numbers

  • PN: 242991 (2,800-2,900 rpm stall)
  • PN: 242992 (3,200-3,300 rpm stall)
  • PN: 242993 (3,600-3,700 rpm stall)
  • PN: 242993 (4,100-4,200 rpm stall)
The bolt-together design allows for user servicing–cleaning, rebuilding, or changing the stall speed–while still providing a higher level of strength throughout the entire assembly. Each torque converter is computer balanced before it leaves the factory. This helps minimize the chance of component vibration at speed. Honestly, it is a simple remove and replace operation when the torque converter is delivered to your door.

“These units are more tunable and overall less time consuming,” said Miller. “If you send a converter in for stall adjustment, you are looking at two weeks turn-around time, and most of that is shipping,” he added.

“Instead of sending the converter in, all a person has to do is call our tech line and tell us the changes they have made to their vehicle. Whether it is a cam change or whatever,” Miller explained. “Our tech crew will tell them what tops or stators they need and they can be ordered right there. The parts will be sent out and all the consumer needs to do is pull the transmission back and slide the converter out. They can make whatever upgrades needed and reinstall the converter. It will take longer to unhook the transmission and pull it back than it will to make the internal changes to the converter.”

Features & Benefits:

  • High-stall, triple-disc converter design improves vehicle launch & overall performance while increasing lock-up torque capacity
  • Bolt-Together design allows users to replace roller bearings & lock-up component–enables both easy stall changes & rebuilds
  • Each unit is hand-assembled for precise tolerances
  • Hand-brazed impeller & fully furnace-brazed turbine for maximum strength
  • Simple bolt-on upgrade for GM 4L60E applications

We had the transmission bolted back in place and after a couple of quick fluid checks, we were ready to hit the track. Sadly, the track was not ready for us until much later.

Making The Swap

Just as Miller had described, changing the stock converter out with the TCI bolt-together lockup torque converter (PN: 242991) was as simple as unbolting the transmission, sliding it back, and pulling out the old converter. Installation was a reverse of this process using the new converter. You should lubricate the front pump seal and pump bushing on the transmission prior to installing the torque converter onto the transmission input shaft. This will prevent problems later if you want to remove the torque converter.

There are two splines that engage with the transmission pump. Carefully align the converter with the input shaft and slide it into place.

Rotate, lift, or tilt the converter as needed to engage the splines and the pump drive lugs. When installed correctly, the converter should slide all the way back to the point where it almost contacts the adapter bell.

Final Testing

We went back to the 1/8th mile Irwindale Speedway on December 5, 2014 to make some comparison runs and evaluate the “bang-for-the-buck” computation. To clarify, nothing else was changed in the vehicle and the environment was controlled as best as we were able.

The weather had turned a little cooler, as is normally the case in early December in southern California. We expected a slightly cooler track and atmosphere. What we didn’t calculate in was the speed at which the converter would lockup and the inability of the vehicle’s tires to provide the necessary traction to do the test justice.

We fought the track and tires, but ended up proving to ourselves that the crew at TCI Automotive were right about their big bang theory.

We ended up fighting the track and tires for traction, yet we were satisfied with the obvious improvement in the vehicle’s ability to break traction on launch. We instantly knew that if we had fresh drag radials the ET’s would probably hit the five to seven-tenths improvement that TCI told us we could expect to see.

This brought up another interesting point that we confirmed with Miller at TCI. “Some tracks have a difficult surface to work with and the drivers have to de-tune their cars to go faster. Having the ability to change your converter makes a huge difference,” he said. “There is the potential to have three or four different stators or tops and tune the converter to different tracks if the user wants to.” This gave us another reason to love the bolt-together converter.

Despite the conditions and lack of traction, we were still able to show an improvement:

Results

The crew at TCI told us that we could expect between five and seven-tenths improvements in the 1/4-mile with their new bolt-together lockup converter and if the traction had been better, we believe that we could have reached those numbers easily. Our 0.15 improvement on the 1/8-mile Irwindale track indicates that we would have been much closer to the range that TCI quoted us on a full 1/4-mile track.

It’s difficult to reproduce a test and begin again with changing another set of parameters and adding tires into the mix, so we are going to live with these results. We did find some other positives during the test that are worthy of mention.

The proof was there in the time slip for everyone to see.

Our car was driven to and from the track on the surface streets and highways in the area. During this time we did not notice a compromise in drivability.

Lockup converters can be harsh on transmission parts during hard launches as evidenced by the shudder or shake of traditional lockup converters. This was not the case in the TCI converter. Finally, we did not notice a change in fuel economy.

Ultimately we have to say that the TCI bolt-together lockup torque converter for 4L60E transmissions is strong enough to handle big power and torque, it is rebuildable and gives the user a chance to change the stall speed or take the unit apart for cleaning. The unit is a lockup design so you won’t sacrifice freeway manners or mileage. Sounds like a pretty good “bang-for-the-buck” to us.

Article Sources

About the author

Bobby Kimbrough

Bobby grew up in the heart of Illinois, becoming an avid dirt track race fan which has developed into a life long passion. Taking a break from the Midwest dirt tracks to fight evil doers in the world, he completed a full 21 year career in the Marine Corps.
Read My Articles

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