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2001 Chevy Silverado: Looks Are Deceiving

A Surprisingly Subtle 950hp LB7

Mike McGlothlin
Aug 1, 2012
Photographers: Mike McGlothlin
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.
Photo 2/13   |   looks Are Deceiving 2001 Chevy Silverado
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.
Photo 3/13   |   looks Are Deceiving 2001 Chevy Silverado Burnout
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.
Photo 4/13   |   Ambient air first enters the low-pressure turbo, a hybrid journal-bearing unit that shares components from both the Garrett GT55 and GT60. The 88mm-inducer compressor wheel off a GT55 was actually machined down from its original size of 106 mm, and the massive turbine wheel from a GT60 features a 130mm inducer. The smaller compressor inducer allows Nick room to grow should his thirst for horsepower increase. At wide-open throttle, the atmosphere charger contributes 25 psi to the system’s combined 70 pounds of boost.
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.
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.
Photo 5/13   |   A PPE Dual Fueler system allows two stock displacement CP3s to share the job of creating and regulating high-pressure diesel. The dual pumps feed a set of Bosch Motorsport injectors, which were fitted with eight-hole, 100-percent-over nozzles at Exergy Engineering.
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.
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.
Photo 6/13   |   Four satin silver H2 Hummer wheels offer a subtle look and a nice break from the truck’s black-on-black theme. A set of 305/65R17 BFGoodrich All Terrain T/As is mounted on the 17x8½-inch wheels.
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?
Photo 7/13   |   Nick picked up this ’01 Chevy Silverado 2500HD back in 2007 to be used as his company’s EFILive test truck—and within 30 minutes of ownership it was tuned. In fact, over the years it’s been the guinea pig for hundreds of tunes. The truck was originally pewter in color, but Nick had Brett Kehl of Precision Body Works in Crystal Lake, Illinois, paint it Dark Otter Metallic (a color found on late-model Pontiac GTOs).