Pushing Limits: An 800-HP Duramax on a Stock Bottom End

An 800HP, Stock Bottom End Duramax

Wayne Weed’s ’13 Chevy Silverado 3500 is the perfect example of how quickly things can get out of hand when you own a modern diesel pickup. Over the course of the last 20,000 miles, his LML Duramax has gone from work truck to play toy in what seemed like the blink of an eye. “I knew I’d need more than just your average power adders to keep up in truck pulling,” he told us. And, being that the LML Duramax has proven capable of handling big power in stock form, Wayne decided to see how far he could push the stock bottom end. With a dyno-proven 808 hp and 1,517 lb-ft. of torque, you could say he reached that goal.

“DYNO-PROVEN 808 HP AND 1,517 LB-FT. OF TORQUE”

800 HORSEPOWER

After delivering the truck to Illini Outlaw Diesel (IOD) in San Jose, Illinois, the crew there got to work on the near-new Silverado. For fuel, a set of Exergy Perform- ance 60-percent over injectors would replace the stockers, fol- lowed by a Wehrli Custom Fabri- cation dual CP3 system. In the valley, the factory CP4.2 was scrapped in favor of an Exergy Sportsman CP3 pump, while a 10mm stroker CP3 from Exergy gets belt-driven up top. Supplying a steady diet of diesel to the dual CP3s is a 220-gph FASS system. As for the engine, a set of heavy- duty valve springs from Merchant Automotive replaced the factory units, and ARP head studs were installed one at a time.

Subscribe Our Weekly Newsletter

The compound turbo kit from Wehrli Custom Fabrication allows plenty of air to mix in with all that fuel. A billet S484 mounts just behind the passenger side battery and sends air to a 68mm Garrett variable geometry turbo for a send round of compression. Wehrli Custom Fabrica- tion’s 3-inch intercooler tubing, Y-bridge, and a Mishimoto intercooler round out the airﬂow upgrades. ProFab Performance high-ﬂow manifolds and up-pipes help free up the exhaust side of things.

“WAYNE’S STANDARD CAB TERROR WILL BE A FORCE TO BE RECKONED WITH WHEREVER IT GOES”

Any 800-hp recipe gets started here, with a high- flowing lift pump. Leaving nothing to chance, Wayne’s truck benefits from a 220-gph FASS Titanium fuel system—which is capable of supporting up to 1,200 hp.

Wayne trusts a set of Cal Tracs traction bars to keep the rear AAM 1150 and its respective leaf springs in check. Since our shoot, they’ve been pow- dercoated to match the truck.

TRANSMISSION WORK

Because the factory Allison 1000 would never survive the mods listed above, the guys at IOD promptly tore into the six-speed automatic and rebuilt it using a Sun Coast GMax-6 kit with Raybestos clutches. A triple disc, billet stator torque converter from Goerend Transmission would also make its way into the build, as would one of PPE’s deep transmission pans. The Allison also received added strength via a rear housing support from Merchant Automotive.

As for the AAM 1150 out back, it’s bone stock aside from an AFE differential cover. Up front however, the GM 925 IFS received a host of up- grades, including a pair of Kryptonite tie rod sleeves and a solid center link, as well as a pit- man and idler arm support kit from Cognito Motorsports. A set of Suspension Maxx ad- justable torsion bar keys were installed to level the truck.

ADDICTED TO POWER

While Wayne is somewhat new to the diesel performance game, he’s just like the rest of us: he has an unquenchable thirst for more power. In fact, by the time you read this, a fully built LML will likely be sit- ting under the hood—with enough fuel and air on tap to make in the neighborhood of 950 to 1,000 hp at the wheels. Whether it’s digging through the dirt, storming down the dragstrip, or shredding the rear tires, Wayne’s standard cab terror will be a force to be reckoned with wherever it goes. DW

From the pilot’s seat, Wayne has a clear view of any parameter he wants thanks to an Edge CTS2 monitor. In addition to that, he can see how much boost each turbo is contributing, and keep an eye on EGT via three Phantom II Auto Meter gauges along the A-pillar.

SPECS:

YEAR/MAKE/MODEL: 2013 Chevy Silverado 3500 HD

OWNER: Wayne Weed

HOMETOWN: Quincy, Illinois

ODOMETER: 52,000 miles

ENGINE: 6.6L LML Duramax with ARP head studs and Merchant Automotive heavy-duty valve springs

FUEL: Exergy Performance 60% over injectors, Wehrli Custom Fabrication Dual CP3’s with Exergy 10mm stroker and Exergy Sportsman CP3, FASS Titanium series 220-gph lift pump system, Deviant Race Parts tank sump

AIR: Wehrli Custom Fabrication compound turbos with Engineered Diesel billet S484 atmospheric and Danville Performance LML 3794 Stage 2 billet 68mm VVT in valley, black Mishimoto intercooler

TUNING: EFI Live via Motor Ops

EXHAUST: ProFab Performance high-ﬂow manifolds and up-pipes

TRANSMISSION: Illini Outlaw Diesel-built Allison A1000 with Goerend Transmission billet stator triple disc torque converter,

Sun Coast GMax-6 kit with Raybestos clutches, PPE deep pan

HORSEPOWER: 808 hp

TORQUE: 1,517 lb-ft.

TIRES: 275/70R18 BFGoodrich All-Terrain T/A

WHEELS: 18×9 inch Moto Metal MO961

SUSPENSION/STEERING: Kryptonite tie rod sleeves and solid cen- ter link, Cognito pitman and idler arm braces, Cal Tracs traction bars, Suspension Maxx adjustable torsion bar keys (1-2.5-inch of lift)