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Editor’s Note: Longtime automotive journalist and Power Automedia contributor Pete Epple is going heads-up racing in 2016 with the NMCA’s Chevrolet Performance Stock sealed crate motor class with a classic 1967 Chevelle. This story is part three of a multi-part feature on his project, as the car is transformed from a bracket machine to a heads-up track warrior. Epple will narrate the story, and we will follow his progress, from build preparation to on-track testing and right through the end of the debut season.
In the last installment of our build, we left off with a look at our TH400 transmission that we’ve retrofitted for our combination, along with the new 8-inch converter from FTI Performance. Beyond the transmission and converter, we knew the rear end needed some attention. The car had an old 12-bolt from a ’71 Chevelle that had been outfitted with a set of aftermarket 28-spline axles, C-clip eliminators and a spool, and 4.56 gears. While this combo was fine for the big-block that was in the car, we wanted a rearend that would truly be a superior piece.
When it came to the rearend, we reached out to Strange Engineering. After discussing the project, we decided to run the new Ultra Fab fabricated 9-inch rearend that Strange built specifically for hardcore drag race applications.
We reached out to Strange Engineering and decided on a 9-inch with the company’s Ultra Fab fabricated housing. The rear end was ordered with hardcore drag racing in mind. An aluminum spool links the extensively lightened axles, and all of the bearings have been upgraded to low-friction versions. The ring and pinion also received an extensive weight reduction, raising the efficiency of the 9-inch.
The aluminum spool and ring and pinion is housed in Strange’s Pro HD aluminum case. The fabricated 9-inch housing is super-strong, yet lightweight. It retains the factory triangulated four-link mounts, with three extra holes in the lower control arm mounts for rear suspension geometry adjustments and finished off with a set of Strange race brakes. These will help get the car stopped at the big end without adding a bunch of unwanted rotational weight.
Lastly, a chromoly driveshaft was also ordered from Strange to complete the drivetrain. This shaft will be strong enough to take the abuse of repeated transbrake launches all season.
The rearend was complete with a slew of go-fast parts, including a lightweight spool, lightened gears, lightweight axles, and lightweight race brakes.
Next, the focus moves to suspension. For this we didn’t need to change much. The car was already outfitted with a full suspension from BMR Suspension. The front A-arms were replaced with tubular versions with standard height ball joints and polyurethane bushings. BMR’s front A-arms are designed to add an additional four degrees of caster adjustability to the front.
The factory arms allow for about two degrees of positive caster. With the BMR arms, we can get as much as six degrees. This will give us much better straight line stability at high speed. Moving to the rear of the car, the factory upper and lower control arms were replaced with adjustable versions from BMR. The double-adjustable lowers feature heavy-duty 5/8-inch rod ends on both sides, allowing for easy adjustments.
The uppers are also adjustable, but feature a one-inch spherical bearing to handle the high loads of launching the car, and a heavy-duty center adjuster that can withstand any level of abuse. These are tied together with BMR’s control arm reinforcement braces. These braces tie the upper and lower control arm mounts together, strengthening the frame in the process. Lastly, BMR’s Xtreme Anti-Roll bar was installed on the new 9-inch. This 100 percent bolt-on anti-roll bar is strong enough keep the Chevelle flat and level when the transbrake button is released.
BMR Suspension A-arms were previously installed on the car and will be reused for the duration of the project. The front upper and lower A-arms add additional caster to the front suspension for improved high-speed stability. These also affer loads of strength over the factory stamped steel arms.
The suspension is completed with double adjustable coilovers on all four corners from Viking Performance. These will give us the ability to fine-tune the suspension setup to get the launch characteristics exactly where we want them, and keep the tires planted. These shocks have 19 compression and 19 rebound adjustments, giving us more than 360 possible combinations on each corner. We’ll be working closely with Viking during our testing and through the first few races to get a solid baseline setup, allowing us to make the changes we need to keep the car hooking at each track no matter what the track conditions.
For the front brakes, we’re sticking with the Aerospace Components binders that were already on the car. These lightweight streetable brakes do a phenomenal job of stopping the Chevelle. The kit is easy to install and fit perfectly. With the car on the lift, we had the opportunity to pull the front brakes apart and carefully reshim the calipers. There was a slight drag to the front wheels when you spun them due to the inside brake pad slightly contacting the rotor.
The rear suspension is also composed of BMR suspension components. The upper and lower control arm have been replaced with strong, adjustable components. The lower control arms are double-adjustable, with rod ends on each side. The upper are on-car adjustable and feature a heavy-duty one-inch spherical bearing and a massive center adjuster. The system is tied together with a set of BMR's control arm reinforement braces.
We took about a half-day and spaced everything perfectly, eliminating the contact. The shims worked perfectly and freed up the front wheels, reducing the rolling resistance.
Getting the power to the ground is crucial, and it takes the right set of wheels and tires to do so, but we also wanted a wheel that looked great. In our opinion there was no better option than Billet Specialties. We ordered a set of black anodized Street Lites, which look killer on our gray Chevelle. The front wheels are 15×4 with a 1.75-inch backspacing, and are wrapped with Mickey Thompson Front Runners.
Body roll is controlled with an anti-roll bar from BMR Suspension. This heavy-duty anti-roll bar does a great job of keeping the tires planted evenly, and will work perfectly with our new combination.
This will give us a lightweight front wheel and tire package with low rolling resistance that also looks great. On the rear, we went through a few options before finally deciding on the right wheels. Beadlocks look awesome and are a great way to keep the tire in place, but when it comes to class racing, where horsepower is limited, unsprung rotational weight needs to be kept to a minimum. We also looked very closely at the tire options for the class before deciding on a wheel.
The rules allow for a maximum tire size of 28×10.5 non-radial slicks. In an effort to keep weight and rolling resistance down, we opted to start the season on a 28×9 Mickey Thompson ET Drag slick. Knowing this was the tire size, we opted to run matching black anodized Billet Specialties Street Lites in a 15×8-inch configuration on the rear, providing us plenty of room in the wheelwell and enough width to run the wider tire if we need to. Given the power of the engine and the weight of the car, combined with adjustable suspension, we feel there is no reason we should have any trouble hooking on the smaller 9-inch slick.
The fuel system also needed to be addressed. The car was previously outfitted with an Aeromotive fuel system, which was designed for a carbureted application. It features one of Aeromotive’s Stealth fuel cells with an A1000 electric fuel mounted inside. The car was used for both street and strip applications in the past, so it had a 15-gallon fuel cell mounted in the trunk. Being that the DR525 is a fuel injected engine, a few pieces of the fuel system need to change.
Wheels are an important part of the puzzle. For this we turned to Billet Specialties. We wanted a set of wheels that looked great, were lightweight, and fit the look and theme of the car. The Street Lites were the perfect choice. When we first started planning the build, we opted for a set of wide wheels with deadlocks (hey, they look awesome!). When we actually starting thinking about it the way we should have, we decided to go for lighter, narrower wheel with no beadlock.
We started by pulling the 15-gallon cell and replacing with a six-gallon version of the Stealth fuel cell. This will give us all the capacity we need for a dedicated drag car, and help us shed some weight in the process. The A1000 pump was quickly swapped from one cell to the other, and the mounting brackets were modified to securely hold the cell in place.
Per the rules, we are limited to what catalogers are legal. We didn’t see any other choice but the Racepak Sportsman logger. It comes with internal sensors for engine and driveshaft RPM, battery voltage, and a single 12v event. We opted to expand the our Sportsman to be able to log using all 18 available V-net channels.
Moving forward, the -8 AN and -6AN feed and return lines were kept in place, but changes were made once we got to the regulator. The old regulator allowed us to run the necessary 5 to 7 psi of fuel pressure for the carbureted big-block. The EFI DR525 requires much more fuel pressure, which is easily attainable with an EFI fuel pressure regulator. We picked up a suitable regulator from Aeromotive to match the rest of the fuel system. The system was completed with a stock fuel line adapter for the LS fuel rails. We also added a fuel sample valve, per the rulebook. We are required to run VP Racing C10, which is a 96 octane, unleaded race fuel. Every competitor is subject to random fuel checks, which is the reason for the sample valve.
When it comes time to put the car on the dyno, and ultimately the track, data is going to be our best friend. The rules allow for only certain dataloggers for Chevrolet Performance Stock. We opted for the Sportsman logger from Racepak. The system is fairly simple and does exactly what we need it to do. It features internal sensors for engine and driveshaft RPM, battery voltage, a two-axis G-meter, and a single 12-volt event. It can also be expanded to log up to 18 total V-net channels. We opted to upgrade our Sportsman to be able to log using all 18 channels, which we will utilize for testing and race days.
We also opted for the OBDII interface. This will allow us to log anything the computer sees, like timing retard, knock sensors, and engine vitals like oil pressure and water temp without having to add additional sensors.
To make this a little easier, we also opted for the OBDII interface, which will allow us to log anything the computer is seeing. This will allow us to easily watch things like the timing curve and fuel trims, or engine vitals like oil pressure and water temperature, without adding extra sensors. Data will be one of the make-or-break pieces of this program for us. The ability to make intelligent changes leading up to race day can be the difference between winning and going home early, and we wouldn’t be able to make those decisions without our Racepak datalogger.
In the grand scheme of building a race car, there are an incredible amount of things to cover, even when starting with an existing racer. We strongly feel the hard work will pay off, and once we have a few races under our belt, we hope to be a frontrunner in this very competitive class. It will all come down to making the right moves and being as prepared as possible. For right now, we feel we are on the right path, and we will know much more once we start testing on the chassis dyno and at the race track.
