Twin

Diesel of the Week is presented by

The diesel side of our industry has really been cranking up its game to 11 recently. As such, there are a ton of folks going faster than they ever have before in diesel-powered vehicles, and one of those people is Mattie Graves.

Mattie Graves competes in the Outlaw Diesel Super Series (ODSS) dragster class, and is the only female doing so in a class that already has very few competitors in general. We caught up with her during the ODSS weekend at the 2022 UCC competition where she was competing along with the help of her family and support from her dad's diesel shop, Hollyrock Customs, located in Hollywood, MD.

From a young age, Mattie was always by her dad's side when it came to cars, trucks and racing, so naturally, it wasn't long before she expressed an interest in driving. What started as casual Friday-night racing at the local track in her F-350 soon turned into high-octane drag racing thanks to a last-minute purchase of a dragster off of Facebook Marketplace.

Mattie is still a fairly new competitor in diesel drag racing, but she's proving herself out on the track and closing the gap on other much more tenured folks. In tandem with getting more track time and passes, Mattie and the team are experimenting with a new setup this year for the twin-turbo Duramax engine housed in the back of the dragster.

"It's a true twin-turbo LML Duramax, which in ODSS you see a lot of Cummins," Graves says. "There's very few of us Duramax people left. We stuck with the Duramax because it's what my dad has always used, and it's been tried and true. I’m not going to switch that up yet."

The Duramax is based off of an LML block, but has all LLY-based fueling supported by S&S Diesel Motorsport, including dual CP3 pumps and big 400% over injectors.

Wagler Competition Products handled all the machining work and provided the billet crankshaft and pistons for the rotating assembly.

Arguably the most interesting piece of the puzzle in this engine build is the twin-turbo setup, which is a rare sight in the diesel racing world. With most racers opting for compound turbos, a big single, or even triples, it isn't often you see true twins.

"A lot of Cummins guys always do a big single, and a couple of Duramax guys have tried it as well," she says. "My dad had triple turbos on his crew cab, so we came into this knowing we wanted to do something different. We had a set of Stainless Diesel twins sitting around so we said sure, let's fab it up. We came out and it worked, so we stuck with it."

Mattie and the team also run nitrous alongside the turbo set up, allowing for a super-quick, 4-second machine.

"We run nitrous, so we have a spool kit, and then a second kit that comes on between the one-two shift," she says. "We’re not using a whole lot and it's very small, so we have plenty of room to work with. The turbos are doing great spooling at the line so we know we can get to where we want to be at ET wise."

Currently, Graves holds a personal best time of 4.54-seconds in the eighth mile.

"We definitely want to try to get into the 4.20s and by the end of the season, we want to be close to 3.90," Graves said.

Mattie's future in this sport is looking bright, and she is excited about new challenges to come, such as PDRA.

"PDRA is definitely a lot more competitive in Top Dragster," Graves points out. "You have dragsters that are running 3.70-3.80, so we would like to get this more dialed in so that we know we can also hang with them. We’re going to try and we’re just going to put our best foot forward and see how we do, and mostly just to get my name out there. I love ODSS, but we’re also seeking more seat time anywhere we can find a race that I can put this dragster in."

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].