Turbocharged and Nitrous-Assisted 6.8L Cummins Engine - Engine Builder Magazine

Turbocharged and Nitrous-Assisted 6.8L Cummins Engine

Ryan Milliken and Rod MacMaster teamed up to build a diesel-powered Corvette to compete with the best of the PDRA Pro Boost class. Thanks to Freedom Racing Engines and Midgets Diesel Performance, among others, the turbocharged and nitrous-powered 6.8L Cummins engine was showing great signs of success. However, its now back to the drawing board for this Diesel of the Week.

Diesel of the Week is presented by

If you follow Ryan Milliken and Hardway Performance on social media, you already know Ryan is a busy guy who gets to do some very cool things with diesel vehicles. Not only does he campaign his own Cummins-powered Chevy Nova with some great success, but he helps others reach new heights within the performance diesel world.

Most recently, Milliken got together with Rod MacMaster to bring something completely different to the PDRA’s WS Construction Pro Boost class. The pair have been hard at work getting a new Hardway Performance-tuned, Jerry Bickel Race Cars-built Corvette ready for Pro Boost action.

Where this car differs from every other car in Pro Boost is through its use of a 6.8L Cummins engine, machined and assembled by Freedom Racing Engines. Milliken’s exploits with his own small-tire diesel Nova and this platform include record-setting performances in the X275 class.

The Corvette’s Cummins engine features Wagler Competition billet connecting rods, a Wagler billet cylinder head, and Wagler’s billet cover front-and-center on the engine. Freedom Racing Engines spec’d Diamond custom pistons that absorb the hit from the 106mm Harts turbo, which is controlled by the first-ever high-pressure 60mm Turbosmart wastegate. Manton supplied a roller valvetrain for the engine and a fuel system from S&S Diesel Motorsport completes the package.

While the Harts turbo packs a punch, the Pro Boost class also allows nitrous, so of course this 6.8L Cummins is also sporting nitrous courtesy of David Vasser from Nitrous Outlet. He whipped up a six-kit array for MacMaster and his turbocharged six-cylinder diesel. A Suncoast torque converter works in conjunction with an M&M Transmission Turbo 400 unit and a custom torque converter dump system from Pete Harrell at Harrell Engine & Dyno.

The install of the engine and final fabrication were recently completed by Andrew Tovornik and the team at Midgets Diesel Performance in Davidson, NC, and Milliken handled the tuneup at the track, using his experience with his Nova to guide the program along.

“We never imagined we could make the power we make with Ryan’s Nova, and now that he has found a way to make the engines live making power, that could let us enter a race where all the engine combos say Hemi,” Rod MacMaster says. “We would like one of those lines to say Cummins. We will see if we can make our dream true soon enough.”

It took Milliken several years to get his Nova to work properly for X275, but the learning curve for this program will likely be considerably shorter given the expertise of the partners involved. Still, MacMaster wants to hedge his bet.

These engines make a boatload of torque, and through the converter dump system and transmission lockup system from M&M, Milliken has been able to tune the power management in a fashion that doesn’t upset the chassis.

MacMaster has readied himself for driver duty by attending Frank Hawley’s Drag Racing School. Initially, the team will sort out the car at a couple of diesel-specific events, and how quickly Milliken is able to make magic will determine its arrival in Pro Boost.

One of those diesel events Milliken and MacMaster were targeting was the Rocky Top Diesel Shootout in Crossville, TN the weekend of July 29-30, 2023. The weekend started strong for the duo and their new Cummins/Corvette combo.

“Q3 this morning .0264 on the tree 1.01 2.77 4.18 down track, really focusing on the short track while the rest of the pass is on cruise control,” Milliken posted on Facebook. “Almost have the wheel speed and chassis looking right, hoping for a .99X 2.6X coming up this afternoon in E1! We didn’t come here for a 1.01!”

A .996 60-foot at Mooresville Motorsports Complex

Looking to improve on the 1.01 60-foot time, Milliken and MacMaster made some adjustments and they paid off. The Corvette came back and made a .99 60-foot. However, that small victory was short lived. The following day, after the car seemed to be headed in the right direction, every racer’s worst fear came to be.

“The car shook the tires real hard up front with the same settings as yesterday,” Milliken told his Facebook followers. “The car turned hard left during tire shake and bounced off the wall about 100’ out. Chutes were out immediately with fire suppression right after before the car even stopped. It’s mostly cosmetic, but without a doubt the fire suppression system saved this car from being a total loss!

Rodrigo Penaloza MacMaster is 110%, but I’m taking him to ER anyways at the advice of paramedics because he’s asthmatic and inhaled fire, smoke and fire suppression. All safety equipment did its job and thankfully this is a part of racing we’re well prepared for. Will be back out SOON!”

Obviously a devastating blow to the team’s efforts with this 6.8L Cummins-powered Corvette. However, Ryan has stated that the car is repairable and they plan to be back as soon as they can, which is great news for the diesel community and those looking forward to seeing this car in Pro Boost. We know we can’t wait to see it on track once again!

Diesel of the Week is sponsored by AMSOIL. If you have an engine you’d like to highlight in this series, please email Engine Builder Editor Greg Jones at [email protected].

You May Also Like

Turbocharged 5.9L Common Rail Cummins Engine in a 1947 Ford

After sitting in his father-in-law’s backyard for a number of years, this 1947 Ford was gifted to Chase Wells’ wife. Chase owns 1 Way Diesel Performance and knew someday he’d bring the truck back to life. He did so using a 5.9L common rail Cummins engine on a special episode of Texas Metal’s Loud and Lifted. Check out the result.

There’s a lot of viral diesel content out there on the internet showcasing unique diesel builds, but how many can say they’ve built up a business that is constantly being featured on network television? Chase Wells, owner of 1 Way Diesel Performance, is one of those guys who is humble at heart, but could brag all day if he wanted to.

1,000-HP Capable 6.7L Powerstroke Engine

Nick Stoner, a customer of Kill Devil Diesel, recently got his fully built 6.7L Powerstroke engine – a build Nick wanted to be capable of 1,000 horsepower. However, Nick is no longer building the truck the engine was going into, so this badass diesel engine is for sale. Check it out.

6.7L Powerstroke engine
Turbocharged 6.7L Second Gen Cummins Engine

Thanks to attending a truck pull event at an early age, Sean Purdy can’t shake his passion for diesel trucks and engines. He recently completed a fresh build on his 1999 Ram 2500 with a turbocharged 6.7L Cummins second gen-swapped engine.

6.7L Cummins engine
Turbocharged 5.9L Cummins Engine

As an industrial millwright, Devan Leeds has a lot of knowledge and skills with his hands. He’s also a thrill seeker when it comes to high-speed vehicles. Case in point, his ’03 Ram 2500, which features a rowdy, turbocharged 5.9L Cummins engine under the hood. Check it out!

Leeds Fabrication 5.9L Cummins
Compound-Turbo 6.0L Powerstroke Engine

Steve Burton of New Performance Automotive and Chris Moore of Flatwoods Diesel Performance recently teamed up to build this compound-turbo 6.0L Powerstroke engine. Check it out!

Other Posts

Demon Motorsports’ Turbocharged Toyota 2JZ Engine

It was hard not to noticed Damon Elff’s Toyota Supra and its turbocharged 2JZ engine during Sick Week 2024 as it was basically the only Supra there, and the 2JZ made some wicked sounds at the start line. We got a chance to speak with Damon, who owns Demon Motorsports, about his Supra/2JZ combo and

JBR Engines Shop Tour

JBR Engines is 4-cylinder central, and we love it!

Turbocharged 5.0L Coyote Engine

This 50th anniversary Mustang Cobra Jet features a turbocharged 5.0L Coyote engine and it’s one of the fastest Mustangs in Mexico. That said, there’s still room for improvement, and Martin Martinez of Junior Performance plans to make it even faster!

Hot Shot’s Secret Stiction Eliminator

Hot Shot’s Secret Stiction Eliminator is engineered to remove stiction, the sludge and varnish created from burnt oil, while also lubricating.