Chad's little roadster impressed everyone at the 2008 TS Outlaw race, and at 2,920 pounds was one of the lightest cars in attendance.
One of the quickest and most interesting rides out there in the world of diesel drag racing is Chad Riley's '30 Dodge roadster. In drag racing, weight is a very important factor that many diesel enthusiasts have yet to embrace. Consider that we have plenty of vehicles generating more than 600 hp in our magazine, yet few can run low 9s in the quarter-mile at more than 140 mph like Chad's can. What makes his engine on wheels special? It weighs a mere 2,920 pounds with a driver. At that weight, it doesn't take much power to go fast.
It does take some power though, so Chad couldn't just drop any old engine into the 125-inch wheelbase rod. Chad decided on the superior airflow from a 24-valve head matched with the power capabilities of a Bosch P7100 pump. The engine itself is mostly stock internally, save for a set of Haisley firerings to keep the head gasket from making an early exit. Power comes courtesy of a T6-based turbocharger wastegated to 70 psi of boost, and a pump and set of injectors from Chad's own company, Diesel Performance Unlimited. Chad figures his engine makes about 600 hp on a "mild" tune, or about 800 hp once the multistage nitrous system is activated.
Moving back in the drivetrain, a Coan Turbo 400 transmission and Gear Vendors overdrive are used to send the torque back to a 2.50-geared Ford 9-inch. When asked about his interesting transmission choice, Chad said, "It's a Coan Pro-Mod transmission. If it can handle 2,500 hp from a Pro Modified, it should be able to take what we're dishing out." The 2.50 axle gears keep the engine in its powerband and under load, so the turbo is churning out plenty of boost.
Chad's philosophy is diesels are built to be powerful and reliable engines, so building an 8-second drag vehicle with off-the-shelf parts is something that anyone should be capable of doing. His roadster is a rolling testament to his speedy philosophy, and it just keeps getting quicker. Since 2004 when it first ran in the 9s, it has only been down the track about a dozen times. Now that diesel drag racing has become more popular once again, Chad has dusted it off and hit the event circuit. At the 2008 TS event, Chad won his class and ripped off a 9.0-second quarter-mile time in qualifying. What's scary is that there is a lot left in the ride. "I think we can get into the low 8s pretty quickly with some more tuning," Chad says. "And if someone really wanted to, they could easily duplicate this entire car." So what are you waiting for? Go out and build one for yourself.
This awesome-looking mill was built by Chad's shop, Diesel Performance Unlimited. Though the 5.9L Cummins long-block is mostly stock, it still makes good power, thanks to a healthy mechanical injection system and a monster turbo.
Would You Drive It? Since Chad built almost the whole roadster himself, everything from the engine to the chassis work (it originally was a 110-inch wheelbase car), he gets the fun of driving it. Although Chad's roadster is something that anyone could build, we're not sure that everyone would want to drive it. The unique pedal arrangement, combined with the open cockpit, make for a pretty wild ride, and seeing the roadster shoot flames out of the exhaust while making its run made us feel a little queasy. "At one point, I think there were sparks shooting over my shoulder," Chad said. So would you drive this thing? We still would.
Speaking of monster turbos, this custom unit was also built by Diesel Performance Unlimited. A 3-inch Garrett wastegate keeps the turbo from overspeeding when the nitrous hits. | 
An awesome one-off custom header that you can't have was built just for this application. Wait, did we say you couldn't have it? Turns out that not only does this header fit '89-'02 Dodges, but it is available to anyone for the reasonable price of $900. | 
An extra 200hp kick is available if the need arises in the form of a nitrous system using NOS parts. Chad uses one stage to get off the line, then hits another while going down the strip. |