When we think about trucks making big horsepower, we usually picture exotic, one-off, flashy parts, and virtually every aspect of the engine receiving upgrades. But Nick Priegnitz’s ’01 Chevy Silverado is contradictory to this popular belief. While the LB7 Duramax engine has been fortified, it retains much of the stock hardware. How does he get away with it? And how has the GM V-8 accumulated more than 60,000 trouble-free miles since being bolted back together? Read on, and we’ll tell you.
The answer is in the tuning. As the owner and mastermind behind Duramaxtuner.com, Nick has years of experience using EFILive’s tuning software—and many consider him the premiere tuner in the country when it comes to GM’s 6.6L. As a general business practice, his custom ECM calibrations yield big power gains, great driveability, and very low smoke levels. These same principles apply to his personal vehicle, which is one of the most streetable 950hp trucks we’ve ever been in.
Ambient air first enters the low-pressure turbo, a hybrid journal-bearing unit that shares
With what some would consider a mild engine build for a truck that gets more than 900 hp to the ground, much of the LB7 engine went unmodified. Key areas of improvement entailed replacing the bend-friendly stock connecting rods with billet-steel units from R&R Racing Products and cutting down the stock pistons (removing the outer lip, which is prone to holding in heat). Aside from a set of SoCal Diesel’s upgraded valvesprings, the engine sports the factory cylinder heads, camshaft, and push tubes. ARP head studs keep the heads clamped to the block.
The engine’s forced induction needs are met thanks to a compound turbo arrangement, which consists of a Garrett GT4202 over a massive GT55, GT60 hybrid. The combination of a quick spool valve and an external wastegate on the GT4202 keeps the system highly functional and durable. Nodular iron exhaust manifolds coupled with stainless steel up-pipes from ProFab Performance provide uncorrupted exhaust flow and help drive the high-pressure turbo more efficiently. On the intake side, a BD intercooler keeps the intake charge entering the engine cool.
A PPE Dual Fueler system allows two stock displacement CP3s to share the job of creating a
Just as two turbochargers are better for making horsepower, the same goes for injection pumps. A Dual Fueler system from PPE sits under the hood and consists of two stock displacement CP3s sharing the workload. Beneath the LB7’s valve covers rests a set of Bosch Motorsport injectors, which were modified by Exergy Engineering and fitted with nozzles that flow 100 percent more fuel than stock.
As for the Allison 1000, it was built locally and treated to a host of upgrades. The internals came from the experts at Sun Coast Converters, including a billet input shaft. A Precision Industries Vigilante series triple-disc torque converter got the call for power transfer. Making sure the transmission and engine meshed perfectly was left up to Nick and a few strokes of the keyboard. Putting his vast knowledge of EFILive to work, he tailored the ECM and TCM tuning to his liking, which resulted in a truck that spools great, shifts firm, smokes little, and pulls like a freight train.
Four satin silver H2 Hummer wheels offer a subtle look and a nice break from the truck’s b
We’d be doing you a disservice if we failed to mention that Nick’s truck is also a tow mule—and it’s even got the gooseneck hitch to prove it. During the spring and summer months, it’s hooked to a 37-foot trailer and transports a 2.6 Class common-rail Dodge to truck pulls. Detuning the Chevy for tow duty simply requires a couple taps on the Edge CTS monitor, on which a 700hp tow tune is selectable.
Nick picked up this ’01 Chevy Silverado 2500HD back in 2007 to be used as his company’s EF
It’s trucks like this that define the diesel enthusiast era. Just when you think a 950hp truck can’t be made streetable, it is. Right when you assume a stock-appearing diesel is a run-of-the-mill rig, it isn’t. And as soon as you’re convinced an 11-second ride can’t double as a workhorse, you see it towing 16,000 pounds down the highway. See what we mean?
Major reinforcement measures taken during the LB7’s rebuild were the addition of R&R Racin
Sitting in the factory location, a 75mm Garrett GT4202 drives the truck’s compound turbo c
To solve any toe-in problems associated with the truck’s independent front suspension, Nic
Preparing the five-speed Allison for high-horsepower duty was a Stage IV rebuild kit from
A variable-resistance knob mounted on the dash is for a fuel mixture controller switch. It
Even though A-pillar gauges monitor EGT and the boost pressure of each turbo, most vitals