THE GAME CHANGER

INSIDE DHD’S RECORDSETTING DURAMAX

Many will immediately recognize the charred front clip on this ’06 Silverado and remember when it went up in flames at Ultimate Callout Challenge 2019. But in 2021 it became known for something even bigger: being the quickest 4x4 Duramax on the globe. To be clear, the Dirty Hooker Diesel (DHD) Chevrolet known as “Last Minute Hooker” is still a U.C.C. truck, but this year it entered the shark tank that is the Outlaw Diesel Super Series’ Pro Street class to go head-to-head with some of the fastest trucks in the world. Right out of the gate, driver Tyler Burkhard put up 5.24 and then 5.23-second passes in the eighth-mile. Then came the trip to Indianapolis…

The weekend of May 21-23 was a big one for the Dirty Hooker Diesel team. Not only did they compete in the Ultimate Callout Challenge with the truck, but—in addition to winning the ODSS Pro Street class—also collected a 5.03-second timeslip at 149 mph. That’s a ton of abuse for one engine to take in a single weekend, but DHD’S Duramax survived (and dare we say, thrived, during) each torture-test, persevering without so much as a hiccup. So how did they do it? And what’s the rest of the truck’s recordsetting setup?

It starts with a sound parts combination from oil pan to turbo, a happy chassis, a Turbo 400, and the right people behind you. In this case, it’s a family effort revolving around DHD owner Tony Burkhard and his sons Tyler and Seth, but also a team effort with everyone at DHD having a hand in the race program. Together, they’ve made a conscious effort to reset the bar for the Duramax—and they have no plans to let off anytime soon. Only here will you get the full scoop on the world’s fastest four-wheel drive Duramax, a truck that may have even broken into the 4’s by the time you read this.

When you’re prepping for war, it pays to have the right weapon in your arsenal. The foundation of the Duramax in DHD’S Pro Street truck starts with a billet-aluminum block from LSM Systems Engineering. The rotating assembly consists of a billet Socal Diesel crankshaft anchored in place via billet main caps and ARP main studs. It swings a set of aluminum connecting rods topped with Diamond Racing pistons. A Wagler Competition Products camshaft controls the valvetrain, and billet-aluminum Wagler cylinder heads fitted with larger valves mate to the block by way of tool steel head studs. Both the block and head are fire-ringed to stand up to the abuse that comes with 2,500-plus hp, and a dry sump oil system keeps the 460 ci Duramax alive at that power level.

If you were wondering where the sizable piping that’s routed through the firewall was headed, it culminates here—at a Wehrli Custom Fabrication water-to-air intercooler. As truck pullers, it’s not surprising to find this technology being employed in DHD’S drag truck, and—in conjunction with the ice box mounted at the back of the cab—it does a tremendous job of keeping intake air temperature manageable. All that hot, compressed air leaving the turbo registers a cool 70 degrees F once through the intercooler. To the left of the intercooler, you’ll find the Bosch Motorsport 15.1 stand-alone ECM that controls the Duramax. It’s been fine-tuned by Phil Devries in the past, with DHD’S Chad Thorley recently taking the reins and running some of the Bosch software.

DHD high-flow exhaust manifolds and up-pipes help drive the front-mounted Precision charger, with double stitch titanium manifold blankets and heat wrap aiding efficiency. Also notice the Wagler cast street intake in the valley, which with its V-band connection point ensures there are never any issues forcing 80-psi worth of boost into the heads. Gear-driven off the billet front cover are two stroker CP3’S from Exergy Performance. The 14mm pumps deliver fuel to Exergybuilt and balanced injectors fitted with 400-percent over nozzles.

The turbo parked in front of the engine is unmistakable. The giant T6 charger from Precision Turbo & Engine sports a 106mm compressor wheel and thrives at the 6,000-plus rpm the Duramax regularly sees. On a typical, low-5-second pass it can produce as much as 80-psi of boost, a peak that’s limited thanks to the use of dual 45mm Precision wastegates. Two spooling stages of nitrous are employed to bring the big 106 to life during staging, and three more stages are progressively brought into the fold during the course of a race. But despite the capacity to spray all kinds of nitrous, to date things have been kept pretty conservative, with roughly four pounds of nitrous being consumed each time down the track.