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Apr 12, 2024

C8 Corvette ProCharger Supercharger: LT2 Install and Dyno Test

Related Video The Chevrolet C8 Corvette revolutionized the layout of the Vette. Since its inception the Corvette has always had the engine mounted forward of the driver, but with the C8 it is nestled

Related Video

The Chevrolet C8 Corvette revolutionized the layout of the Vette. Since its inception the Corvette has always had the engine mounted forward of the driver, but with the C8 it is nestled behind the driver. This mid-engine layout is great for weight balance but it complicated many aftermarket performance upgrades that were pretty commonly done to Corvettes, one of the most common being adding a supercharger. The LT2 engine layout was a challenge, but one that ProCharger was willing to tackle. It took a while to figure out the best path for a do-it-yourself C8 blower kit, but they figured it out and now you can now add a healthy dose of boosted bliss to your own LT2-powered C8 Corvette!

To talk about the challenges, we asked ProCharger's engineering team lead Dan Rosner to give us the 4-1-1 on what it took to make a supercharger kit for the C8. "The basic challenge to the entire design was the fact that it is a mid-engine platform. How do you drive a centrifugal supercharger and where do you place/mount the supercharger? While considering these two main variables we have to remember we sell to the basic car enthusiast, people who may not have lifts or large equipment. Then the question follows, how can we create a mid-engine platform that does not require removal of the entire engine cradle? With these questions in mind, you begin developing a system that is dramatically different than what we have ever done, but has the same basic design so that our dealers can become familiar with and have no hesitation in installing it," recalled Rosner.

Rosner continued, "Basically, the drive pulley could fit in one location and the ProCharger could fit in one location, our challenge was to figure out how to join the two moving objects on opposite ends of the engine. For the drive pulley we were limited in space due to the proximity of the motor to the firewall, and the overall shape of the firewall and the supporting equipment on the car surrounding it. A location was found that could support the largest drive pulley possible utilizing the factory six-rib belt and provide a path for a driveshaft to the back of the engine. The location of the pulley also had to provide a straight unobstructed path to the rear of the engine. At the rear of the engine is a compact cog drive system that drives the ProCharger."

As ProCharger's Director of Communications and Calibrations, Erik Radzins, went on to explain, "Every modern-day ProCharger street/strip system design utilizes our industry leading air-to-air intercoolers. How do we integrate intercooler technology into a mid-engine platform that does not have a large front grille, with the supercharger mounted in the rear of the car? That is where we took our C7 engine intake manifold expertise to the next level by integrating an air-to-water core into our C8 intake manifold. This allowed for a more feasible opportunity to cool the additional air being introduced into the engine. However, we still have a desire for fresh air as a daily driven air-to-water system should utilize a heat exchanger (small radiator) to cool the water. That is where being able to utilize the one source of fresh air in the back of the vehicle the side air duct was critical.

"Then the air inlet needs to be able to support the air requirements of the ProCharger, fortunately we were able to develop an air inlet that utilizes a factory air duct where the factory air box went. This however required utilizing valuable trunk space where the Targa top is relocated. Fortunately, the shape and positioning of the inlet was able to be manipulated where the Targa top and golf clubs will still fit in the trunk," remarked Radzins.

Before starting the install ProCharger made sure to baseline the 2021 C8 Corvette.

On the Mustang dyno they knocked down a best pull of 458 hp and 420 lb-ft of torque from the stock LT2 V-8.

At first glance the mid-engine design of the C8 Corvette is intimidating, but this installation isn't as challenging as you think. According to ProCharger's Ken Jones, "The C8 supercharged system is actually 'easier' to install compared to the previous C7 body style since there are no body panels that must be removed, such as the front bumper in the case of the C7. The C8 system only requires an inner fender liner to be removed, the rear trunk panel, and the car's under panels. So yes, even though the mid-engine layout was a complex undertaking for engineering, it actually makes for a smooth and very DIY-friendly installation of the supercharger system."

After disconnecting the battery up front we pulled the carpet panel from the rear trunk area.

Using a T10 bit we then removed the 19 bolts securing the engine access cover to the trunk.

We could then remove the airbox from the Corvette. Tech tip: As is typical, many of these bolts are 10mm, so make sure you have plenty of 10mm tools since they tend to vanish from the toolbox like socks in the wash.

Remember, this is an overview. Following the detailed instructions in the 76-page full-color installation manual we were able to remove the factory intake manifold from the Corvette's LT2. At this point it's a good idea to either tape up, or stuff rags in, the head ports so nothing is accidentally dropped in there.

It was then time to move under the C8 Corvette. A lift isn't required to do this install but it sure helped. First up was removing the plastic skid plate followed by the rear metal skid/aero plate that was held in place by two 7mm bolts, 21 T14 bolts, and four 13mm bolts. Ziploc bags and a Sharpie will help you keep it all organized.

The great thing about this kit is that the engine doesn't need to be dropped to complete any part of the installation. This also means you need to have patience and the ability to work somewhat in the blind when it comes to installing the front drive assembly. First up was getting the factory four-rib stretch-to-fit A/C belt out of the way. A 15mm socket and breaker bar were used to rotate the tensioner and remove the factory six-rib belt.

After removing three 13mm water pump bolts (and removing the factory tensioner to get more space to work) we could work on installing the first ProCharger pulley bracket.

We could then move on to the front main bracket assembly. Keep in mind that while the C8 Corvette is built on metric hardware, many of the components in the ProCharger kit are standard SAE.

The rear main bracket assembly (RMBA) is a very robust piece. Remember, when we say "rear" we're talking about the side of the engine closest to the rear bumper.

Four bolts secure the RMBA to the passenger-side head. When done, all the hard lines and wire harnesses rested in front of the RMBA.

After removing the four 5/16-inch flanged hex bolts and securing the two bearing caps to the RMBA we were ready to install the driveshaft assembly. To clear the driveshaft we did need to slightly bend one of the aluminum coolant lines. The blower driveshaft was then secured on both ends by the bearing caps.

One of the more challenging steps was feeding in and routing the new six-rib serpentine belt. While a challenge, it was still easier than dropping the engine. Pro tip: Slide the belt onto the factory tensioner pulley last. We then reinstalled the factory four-rib stretch belt.

It was then time to install the very badass ProCharger intake manifold. According to ProCharger the intercooler system is so effective at this low boost level that often a customer will actually see the inlet air temperatures dropping during a dyno pull, sometimes even dropping below the ambient temperatures! This happens due to the extremely oversized intercooler core and high-quality heat exchanger mounted inside the drivers side air scoop.

We then followed the ProCharger instruction manual to remove the driver-side rear wheel and wheel liner so we could install the new heat exchanger.

Behind the liner is a small radiator and fan that must be removed so we can integrate the new ProCharger heat exchanger for the blower.

The new heat exchanger and fan assembly was then reinstalled in the Corvette. It was a clever way to handle the complex challenge of intercooling a mid-mounted engine with limited airflow.

The new expansion tank and bracket were then bolted into place.

And the included -AN hose was used to connect the expansion tank to the heat exchanger. We then installed the intercooler's water pump and filled the system with the recommended coolant.

Moving back into the engine bay, it was time to install the ProCharger blower bracket assembly. We first installed the sub-bracket using, in part, the six 10mm trans cooler bolt locations. Once the sub-bracket was in place we installed the ProCharger main bracket using five 5/16-inch flange-head bolts.

The cog belt had to be installed over the ProCharger driveshaft cog pulley prior to installing the head unit in the car.

It was then time to install the ProCharger shaft assembly onto the P1X supercharger and then slide the whole deal onto the main bracket we had just installed. For the street, ProCharger recommends the P1X but the kit will support bolting on a D1X so long as you're willing to upgrade other parts, such as the clutch.

Next up was routing the intercooler tubing. Designing this was a huge challenge given the tight confines of the C8 Corvette's engine bay, but through a lot of trial-and-error ProCharger was able to find a clean path for the tubing to wind its way from the blower to the intercooled intake manifold.

In this drawing you can better see the path that the tubing takes from blower point A to throttle body point B.

After removing the factory MAF sensor from the factory air box (using a torx bit) and relocating it to the air inlet tube, the new inlet tube assembly could be put in place, adjusted, and tightened down. Tech tip: If the fuel trims appear to be off, the MAF can be rotated to help dial them in.

To dress up the intake and get the worked-over engine bay a cleaner look we installed this carbon fiber intake cover.

After using the new carbon fiber engine cover as a template to trim the trunk carpet we installed it in place of the factory cover we removed at the beginning of the install.

And here's the final engine bay and trunk area. As ProCharger's Ken Jones told us, "The C8 has an amazing look to it, and so does the engine bay. So, the ProCharger system had to function well and look great doing it. The engineers did a great job of creating an intake manifold that matched the style and lines of the engine bay while having great function. Plus, adding carbon fiber options to match those that have the carbon package on their C8 is just icing on the cake. And once again, adding horsepower while not taking away from the usable trunk space was another major perk."

After installing some electrical bits needed for the tune, we were ready to hit the Mustang dyno again. Now keep in mind, this was a very condensed look at the installation. The full-color manual from ProCharger is around 76 pages and has nearly 300 detailed steps from start to finish, but for that trouble you get a huge boost to your C8's performance. As Jones told us, "One of the best things about the C8 corvette is the driving experience. The engine resting behind your head, the seven-speed gear box's lighting-quick gear changes, and the seamless, smooth power delivery. Adding the sounds of the supercharger makes this experience even more amazing, along with the added rush from the smooth delivery of power beyond the factory rating. These are real-world, seat-of-the-pants power gains here up to 150 hp, as opposed to just adding two to five hp from exhaust or a cold air intake. Taking your time, you should expect the install to take between 16 and 18 hours to knock out.

So, what were the dyno results? Well, as everyone knows, engines love boost and the Corvette's LT2 is no exception. Peak horsepower at the tire shot up to 612 hp and max torque went to 514 lb-ft! That's a gain, on this 2021 Corvette, of 154 hp and 94 lb-ft of twist. ProCharger insists you run your Corvette on 91 octane or better gas. But seriously, who puts cheap gas in their Vette?

Of course, it's not enough to build a kit that physically fits the car and knocks down a good dyno number, you need real-world, on-the-road and on-the-track testing to make sure everything stays happy when pushed hard. As Jones told us, "ProCharger engineers took testing to the next level by spending countless hours on the dyno, tens of thousands of miles on the street, and then renting racetracks in various climates to perform road course testing, using several test mules." The team was seeing gains of 8 mph in the quarter mile and 0.3-second improvements in the car's 0-60 mph times. ProCharger expects these improvements to get even better as customers get their hands on the kits and become focused on laying down faster numbers at the track. We're just dying to get our hands on one to see how an extra 150 hp improves an already fun car. If you want to see a video on the very first C8 supercharger kit check out the YouTube video below from ProCharger.