A 70,000 Mile, 650 HP LBZ

Brand loyalty is a funny thing. It’s often considered to be a generational phenomenon. Still, every family has its black sheep—enter Jerseyville, Illinois resident Nate Hansen. Believe it or not, while the rest of his family members had been driving GM products for decades, Nate managed to resist the urge to own one. In fact, his first diesel pickup was an ’05 Harley Davidson edition Ford F250 with a 6.0L Power Stroke under the hood. But after riding in his cousins’ LBZ Duramax-powered trucks, the tide began to turn.

MODDED FROM THE GET-GO

In 2008, Nate traded in his 6.0L and purchased the ’06 GMC Sierra 2500 HD you see here from one of his cousins. “It was a preemissions truck and the first year of the six-speed Allison—and something just told me I needed it,” he told us. Having gotten a taste of what a programmer could do when added to a diesel, he promptly threw an Edge Juice with Attitude and a Bully Dog Triple Dog on the truck. “This is when the truck still had the tiny factory tires on it,” he said of his upgrade timeline. “And they lasted about 3 hours”

Over the next several years, Nate would end up adding a 5-inch Magnaflow exhaust, S&B air intake, Banks Techni-cooler, water-methanol injection, and a 150-gph FASS fuel system to his Sierra. He even ditched the stacked programmers in favor of a Hot +2 E.T. from PPE and squeezed 474hp through the stock Allison transmission while on a chassis dyno. Finally, the need to go beyond simply running a hot tuner surfaced, and the truck ended up at Flynn’s Shop in Alexander, Illinois, for some serious power upgrades.

PUSHING THE LIMITS

On a budget that didn’t quite permit a built bottom end, yet knowing he’d be pushing the limit of the factory LBZ pistons, Nate decided to roll the dice and see what the stock short block was made of. All of the wrenching this go around would take place north of the head gaskets.

To keep the head gaskets alive with the engine seeing more cylinder pressure and higher boost and drive pressure levels, a set of ARP head studs were installed. Next, a set of 60 percent over injectors from Exergy Performance replaced the factory units, followed by the installation of a Dual Fueler CP3 kit and Race Fuel Valve from PPE.

“It was a pre-emissions truck and the first year of the six-speed Allison. Something just told me I needed it.” —Nate Hansen

For air, a single turbo was chosen over compounds as one way to help keep the bottom end happy—That single charger would be a 68mm Cheetah from Fleece Performance Engineering. Improving airflow in other areas, a 3-inch cold side intercooler tube from Dirty Hooker Diesel was added, as well as its 3-inch Super High Flow Y-bridge.

To ensure the Allison 1000 lived behind the newfound power, Flynn’s split the case and fitted the automatic with a Gmax 6 kit from Sun Coast. The torque converter would be upgraded to a 1058 triple disc unit, also from Sun Coast. Both the TCM and ECM tuning—arguably the most important part of any Duramax build—are the work of DuramaxTuner.com.

“A Hot +2 E.T. from PPE squeezed 474 hp through the stock Allison transmission.”

Since making the switch to GM, Nate has zero regrets, especially now that his LBZ runs so well. With its distinctive VGT whistle, smooth drivability, and at least 650-rwhp on tap, Nate’s GMC is a truck most enthusiasts would love to have. It might not be the perfect daily driver, but it’s pretty darn close. UDBG

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Specs:

Year/Make/Model: 2006 GMC Sierra 2500 HD
Owner: Nate Hansen
Hometown: Jerseyville, Illinois
Odometer: 69,500 miles

Engine: 6.6L LBZ Duramax with ARP 2000 head studs, PCV reroute

Fuel: FASS 150-gph lift pump, Exergy Performance 60% over injectors, PPE Dual Fueler CP3 kit, Alligator Performance fuel sump

Air: Fleece Performance Engineering 68mm Cheetah, Dirty Hooker Diesel 3-inch Super High Flow Y-bridge, Banks Techni-Cooler, S&B Filters air intake

Exhaust: MagnaFlow 5-inch, 3-inch MBRP downpipe

Transmission: Flynn’s Shop A1000 with Sun Coast Gmax 6 kit and 1058 triple disc converter, Merchant Automotive transfer case pump rub kit and rear housing support

Tuning: DuramaxTuner.com ECM and TCM tuning w/DSP5 switch

Injectables: Snow Performance Stage 2 water-methanol

Horsepower: 650 to 700-rwhp (est.)

Torque: 1,100 to 1,200 lb-ft (est.)

Tires: Toyo Open Country A/T 325/60R20

Wheels: 20×9 inch XD series Armors

Suspension: RCD 6-inch suspension lift, Rare Parts heavy-duty tie rods, Cognito Motorsports traction bars