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  The Game Changer

Inside DHD’s Record-Setting 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 4×4 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 record-setting 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.

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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.
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.
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 Exergy-built and balanced injectors fitted with 400-percent over nozzles.
The Precision Performance Products air shifter represents a key piece of the puzzle in getting DHD’s Silverado down the track. It’s linked to a Rossler Transmissions TH400, a transmission countless diesel drag racers have turned to in recent years. “We had an Allison in the truck, originally,” Tony Burkhard told us. “But we knew pretty quick that that wasn’t gonna be the answer, so we had to get rid of it.” DHD’s TH400 is a little different being that it’s a four-wheel drive application, but so far it’s proven itself capable of handling whatever the Duramax sends through it. DHD works with ProTorque on the converter side, running one of the company’s billet stator, lockup units. Up until a recent converter change, the truck’s shift points were set at 6,200 rpm.
Obviously, given what happened in 2019 DHD’s Chevy has quite a history on the dyno. So when U.C.C. returned this year, you couldn’t help but pay extra attention when Last Minute Hooker rolled onto the dyno. Fortunately, this time around there were no fireworks, just a few solid passes that yielded the seventh highest horsepower number achieved on the weekend. Here, the team discusses dyno strategy between pulls.
Part of team DHD’s dyno strategy was to avoid having the engine lugged down too low in an effort to avoid dangerous torque levels. On a weekend where the engine would see at least a dozen full-power passes on the drag strip (and that would still be expected to hook to the sled), the game plan made sense. Unfortunately, the engine was spinning 4,000 rpm before full throttle was applied, even though their target start speed was 3,500 rpm. This meant their nitrous wasn’t in the mix until even later than that. In the end, it cost the team a big torque number, even though an impressive 2,104-rwhp was made.
Although torque checked in a tad low at 2,360 lb-ft while aboard the U.C.C./Northwest Dyno Circuit SuperFlow, DHD’s horsepower number was fairly representative of what the truck applies to the track. For instance, when you take the truck’s 4,420-pound race weight into account on its 5.03-second pass at 149 mph, at least 2,050 hp was making it to the ground. With fueling being pulled out of the equation in order to maintain traction on the truck’s launches, somewhere between 2,100 and 2,300 hp is being employed on the back-half of the track.
Capping off their Pro Street win at Outlaw Diesel Revenge in Indy, the guys at DHD pushed to the very bottom of the 5-second range. Their 5.03-second pass was two tenths quicker than the impressive 5.23 they’d posted up just four weeks earlier at Rudy’s ODSS season opener. As well, a 1.28-second 60-foot was achieved on the pass—along with 1.7 to 2 g’s being present on the G-meter. Soon, the guys at DHD hope to not only improve on that 60-foot time, but also lean on the engine even harder. We’ve been led to believe there is a lot more left on the table, so long as the truck hooks. By the time you read this, talk of breaking into the 4’s may even be old news. According to DHD’s Chad Thorley: “I really don’t think seeing mid 4’s or at least 4.7’s is out of line.”
Despite competing in one of the fastest racing categories in existence, DHD’s ¾-ton Silverado still rides on a full factory frame and possesses a steel body. The rear suspension has been four-linked and QA1 adjustable coil over shocks are present, but the front IFS remains. RCV Performance CV axles reinforce the AAM 9.25, as do Kryptonite control arms and steering system upgrades. In the rear, a 10.5-inch ring gear 14-bolt axle—chosen for its tough, three pinion bearing design—is equipped with a spool, Yukon 4340 chromoly axle shafts and DHD’s 11.5-inch billet yoke (which fits the 10.5-inch). In the cab and tied in with the frame is an SFI 25.6 cage.
Much like truck pulling, Tony has made the drag racing thing a family affair. His son Tyler pilots the truck, while his son Seth, the aforementioned Chad Thorley, and all DHD employees play a role in the truck’s upkeep, analysis, and race prep. As far as the team has come in just its first three races, it would not be surprising to see them bring home a Pro Street championship—or even become the fastest Pro Street truck in the world at some point.
It was perhaps the biggest news of 2019, when DHD’s Silverado caught on fire and ran away on the chassis dyno at U.C.C. A catastrophic chain of events, where an atmospheric turbo failure simultaneously severed the fuel pressure regulator’s wiring and cracked the high-pressure fuel lines and intake manifold. With an uncontrollable fuel source, the engine took off to what has been speculated to be as high as 10,000 rpm. But despite seeing extreme rpm and no oil pressure for well over a minute, the Duramax incurred very little damage during the runaway—and the team pressed on, somehow converting the truck into sled-pulling form overnight, and making their call-time with the sled the next day.
An extensive background in truck pulling meant that Tony and crew were the favorite to win in the dirt at U.C.C. 2021. And rightfully so. Last Minute Hooker, outfitted with Giant Puller cuts, a front weight box, and axle changes the night before, put roughly five feet on Second Place and won the truck pull in convincing fashion. And, after all the dust had settled on a weekend where the truck competed (competitively) in both U.C.C. and the ODSS Outlaw Diesel Revenge Pro Street class, the all-billet Duramax required nothing. Tony was quoted as saying: “All we did was change the oil in it.”
Instead of addressing the charred sections of sheet metal, the guys at DHD left it alone. Now, it represents how one team persevered, not even letting a catastrophic, fiery runaway keep them from competing. The day the runaway happened, Tony and team stayed up until 5:30 am the morning of the pull before turning in for bed. If this is any indication as to how they’ll operate a drag racing program, look for them to be at the top of the Pro Street ranks well into the future.

SOURCES

ARP
800.826.3045
arpdiesel.com

Diamond Racing
877.552.2112
diamondracing.net

Dirty Hooker Diesel
989.479.0444
dirtyhookerdiesel.com

Exergy Performance
616.551.4330
exergyperformance.com

Precision Turbo & Engine
855.996.7832
precisionturbo.net

ProTorque
631.218.8700
protorque.com

RCV Performance
815.877.7473
rcvperformance.com

Rossler Transmissions
330.530.5000
rosslertrans.com

SoCal Diesel
661.775.5620
socaldiesel.com

Wagler Competition Products
812.636.0391
waglercompetition.com

Wehrli Custom Fabrication
630.277.8239
wcfab.com

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