Meet the 3,000hp Cummins that went 4.74 at 159 mph and dominated the Pro Street field in 2023.
This ’06 Ram has lived several lives. Under Firepunk Diesel’s ownership, and with Lavon Miller in the driver’s seat, it dominated the first three Ultimate Callout Challenge events. Then it became the first Pro Street diesel truck to run a 7-second quarter-mile, a feat that was followed by being the first to go 4’s in the eighth-mile. Two years after that, the truck returned under Josh Scruggs (current Firepunk employee) and proceeded to put up a 4.86 in the ‘660—the record for a period. Now, in the midst of the truck’s third act, it’s still setting records and winning races—a lot of races.
With an unquenchable need for speed, current owner, Justin Zeigler, is a natural fit behind the wheel. A fierce competitor, Justin would rather grenade an engine than lose a race—and what he did in 2023 is nothing short of remarkable. From the Outlaw Diesel Super Series’ season opener in Rockingham to the final round at Wagler Motorsports Park, Justin and his battle-hardened third-gen won every event on the schedule. Along the way, he reset the Pro Street E.T. and trap speed records with a blazing 4.74-second pass at 159 mph. For the ultimate encore performance, Justin is gunning for a repeat championship in 2024—along with 4.60s right out of the gate.
Enjoy this inside look at one of diesel drag racing’s most dominant and storied machines.
If you’re going to drive it like you stole it every time you let go of the button, you’re going to need an engine that can handle it. Thankfully, Justin runs one of the most trusted power plants in the industry: an Enforcer series Cummins from D&J Precision Machine. Justin’s Enforcer begins with an unfilled, cast-iron 6.7L block that’s been machined to accept sleeves and that also accommodates a deck-plate. A factory-based, 6.7L crankshaft is secured via D&J’s HD girdle, billet main caps and 9/16-inch main studs. The rest of the rotating assembly consists of D&J’s tool-steel, X-beam connecting rods and FSR (forged-steel) pistons with Total Seal piston rings. The block also houses a billet roller cam, complemented with roller lifters.A hand-polished, billet-aluminum, runner style intake manifold ushers air into a Stage 4 D&J cylinder head. The 24-valve head makes use of 1.500-inch diameter super alloy intake valves, 1.450-inch exhaust valves, a high performance CNC valve job, 115-lb springs and Titanium retainers, and is anchored to the block by way of 9/16-inch head studs. In comparison with a factory common-rail head, the Stage 4 D&J unit flows 320 cfm on the intake side (vs. 165 cfm stock).At the top tiers of diesel drag racing, it’s common to find a Garrett GT55 turbo feeding the engine—and Justin’s Enforcer is no exception. The rear-facing GT55 forces 115-psi of boost through a custom-built air-to-air intercooler from No Corners Cut (the same intercooler that saw 189 psi of boost at U.C.C. 2022, when the truck made 3,336-rwhp). The big single, built by Stainless Diesel, employs a 98mm compressor wheel, utilizes a Garrett 1.37 A/R exhaust housing, and mounts to a Stainless competition T6 exhaust manifold.To keep the GT55 (as well as the engine) from seeing excessive drive pressure, dual TurboSmart HyperGate wastegates are present in the polished Stainless Diesel exhaust manifold. Integrating the wastegates, along with fabricating all the turbo piping, was performed by Cody Fisher at Firepunk Diesel. Per the truck’s data log info, the pair of external, 45mm gates limit peak drive pressure to 118-psi. Compare that to the 115-psi of boost the engine sees and you’ve got that perfect 1:1 drive-to-boost ratio that keeps expensive engines and turbos alive at 3,000+ horsepower.You’ll find two 14mm Exergy CP3 high-pressure fuel pumps bolted to the engine’s triple-CP3 front cover. The third spot is occupied by the wet sump oil pump. Stacked behind that, you’ll discover the power steering pump and the Waterman Racing fuel supply pump. The 14mm stroker CP3’s supply fuel (pressurized as high as 34,000-psi) to a billet, triple-feed rail from Exergy Performance, where it’s stored until the 400-percent over injectors call for it. We’ll note that Justin’s injectors are the same units that made 3,336-rwhp on the chassis dyno. The injection system is controlled by way of a Bosch Motorsport MS 15.1 stand-alone ECM, with fine-tuning provided by Lavon Miller.Straight out of the truck pulling world and chosen for its nearly indestructible design, an SCS drop box routes power—from a tough-as-nails Rossler TH400—to the front and rear axles. For the 2023 racing season, Justin campaigned the same turbo 400 from start to finish, and in fact only changed the fluid once. A 12.3-inch billet stator, lockup torque converter from Neal Chance sits in front of the Rossler three-speed. The converter can be re-stalled however Justin wants at the track and, believe it or not, lockup isn’t mandatory in order to get the truck into the 4’s.Now for the truck’s injectables, where both water and especially nitrous are used to perfection. To bring the GT55 to life on the line, a pair of spool jets (a .48 and .52) are utilized, and three Nitrous Express kits join the party after that. ”I can be on the limiter in 1.1 seconds,” Justin tells us. “Then we stack kits on from there.” To help control EGT, two water injection nozzles are positioned post-turbo, with the pressure provided by the nitrous system used to push the water. Each pass down the track consumes 10 to 12 pounds of nitrous, half a gallon of H2O, and roughly a quart of diesel fuel.Shaving weight without sacrificing strength is the name of the game here, with a Moser Engineering 9-inch axle serving duty both front and rear. Justin tells us that, in replacing the front AAM 925 with a Moser unit, significant weight was saved—while nearly 200 pounds were lost by ditching the AAM 1150 out back. An open diff, 40-spline unit resides up front, while the rear Moser is equipped with a spool. Of all the gearing options available with the 9-inch, a 3.23 ring and pinion best complements the truck’s eighth-mile objective.Obviously, traction is a big part of Justin’s success, and the truck’s rear four-link system works to keep the Moser settled and the truck biting. It’s an adjustable arrangement that was developed in-house at Firepunk Diesel, complete with burly brackets and 1.75-inch diameter, .120 wall chromoly tubing. You’ll find a similar setup under many other “Pro” class diesels. Further suspension tunability is on the table thanks to a coilover shock from Menscer Motorsports being present at each corner.You’re looking at all that remains of the factory frame. This section is located under the cab and is only there because the truck was initially built to adhere to former Pro Street rules, which dictated that 3.5-feet of the OEM frame rails had to be retained. To be sure, most of the truck is tube chassis at this point, but the existence of this portion of the original Dodge frame helps illustrate just how long the truck has been a force in diesel drag racing.The last (and arguably most important) piece in the traction puzzle lies in the Hoosier slicks Justin runs. He reports that the 29.5/11.5W-15 Hoosiers last roughly 25 passes before the truck’s 60-foots begin to fall off. “We don’t wear them out,” he explains. “We beat the side wall out of them.” This offseason, Justin plans to switch to a set of Mac Fab Performance double beadlock 15×12’s in rear, and single beadlocks up front. “We folded all the screws over on that 4.74-second pass,” he admits.Going fast safely is paramount in diesel drag racing—especially when you’re talking about 4,400-pound (and heavier) diesel-powered trucks running 4-second eighth-miles. Justin’s Firepunk-built roll cage is built to meet SFI 25.6 standards, which allows for unrestricted competition in the Outlaw Diesel Super Series Pro Street category. Also notice the carbon fiber transmission tunnel pictured here. Provided mid-season by HammerTech Racecars, it helped shave 13 pounds off of the truck’s bottom line and is part of Justin’s overall goal of competing at the class minimum (4,400 pounds) in 2024.2023 will go down in history as one of the most dominant years for a competitor in one of diesel’s fastest drag racing classes. Not only did Justin secure the win at every event on the ODSS schedule in 2023, but he also earned the number 1 qualifier at every race. Then it happened. With perfect weather and track conditions at the Wagler Fall Nationals, the final race of the year, Justin uploaded the 4.7x tune-up he’d been saving since the Rocky Top Diesel Shootout. The result was a 4.749-second pass at 159.21 mph—a new Pro Street record.So, what’s it like to go for a ride in a record-setting Pro Street truck? Upon executing the burnout, getting lined up up and making sure to lock the truck in four-wheel drive, Justin stops short of pre-stage, drags the brake, grabs the trans-brake, flat-foots the go-pedal and then bumps it in. Cutting 1.2-second 60-foots is the norm, with a 1.24 being the truck’s best to date. Somewhere between 1,600 and 1,800 hp is used to get the truck to the 330-foot mark, then what would be considered a very aggressive ramp up of fuel and nitrous ensues. By the stripe, roughly 3,000 hp is being used. “We’re lucky to be able to swing some pretty big horsepower after the ‘330 and drive away,” Justin tells us. “It pretty much pulls 2 g’s or more the entire length of the track.”As for future goals, Justin plans to deliver a knockout blow at the first race of the 2024 ODSS season: put a 4.6x on the board right out of the gate. ”I want everybody to know, all year, that we can do that,” he tells us. With subtle yet fruitful offseason ambitions such as lightening the truck even more and adding beadlocks, improving on the current 4.74 record isn’t out of the question. After all, everyone knows the horsepower is there to pull it off. If conditions are right and traction is there, look for 1.1-second 60-foots and a new Pro Street ET record from Justin and his team come April.
