2003 Lingenfelter Hummer H2

During normal driving, the 6.0-liter/500-horse LPE runs quiet. But mash the gas, and the supercharger and exhaust team to produce a wicked wail that turns heads.

They're everywhere. Wherever you turn, you're almost guaranteed to see a new Hummer H2 cruising down the street or bounding over boulders. We, too, like the H2--so much so that we flogged one on a colossal drive from the Arctic Ocean to Key West, Florida.

Yet, our biggest criticism was that, despite its powerful 6.0-liter V-8, the H2 could use even more oomph. Moving 6500 pounds of boxy weight doesn't happen easily with only 315 horsepower on tap. That's where ace-tuner Lingenfelter Performance Engineering comes in.

Famous for building big power, LPE has boosted the output of the H2's V-8 by an incredible 185 horsepower. The tuner removes the stock V-8, blueprints the 6.0-liter's bottom end, and installs forged pistons and a custom roller camshaft. Atop the short block sit a pair of ported cylinder heads fitted with stainless-steel valves, beefier valve springs, and titanium retainers. A Magnacharger air-to-water intercooled Roots-type supercharger and ported intake manifold perch on the heads, cramming 7 psi of boost inward. Oversize injectors properly funnel fuel as prompted by a reprogrammed factory electronic control unit. A B&B Tri-Flow mandrel-bent, stainless-steel exhaust system quickly vents the spent hydrocarbons and delivers just the right amount of growl while cruising. The final key to LPE's power combo is the addition of a custom torque converter that allows the force-fed engine to efficiently get into its powerband when leaving a stoplight. LPE conservatively rates its dyno-tested package at a square 500 horsepower and even gives a 2-year/24,000-mile warranty.

We were amazed by the test-track performance of the LPE H2. Despite docile street manners, the 6.0-liter roars to life when the gas pedal is mashed and hustles the large-by-huge H2 to 60 mph in 6.3 seconds--almost four seconds quicker than a stock version. If you're bold enough to keep the accelerator planted for 1320 feet, the LPE H2 will treat you to a 14.4-second e.t., which puts it squarely in Mustang GT territory. Plus, LPE's high-flow airbox will soon replace the restrictive factory airbox, which should lop another tenth off the e.t. Want even more? LPE also offers a 415-cube stroker setup if the H2's wimpy 6.0 liters of factory displacement aren't enough for you.

However, all this big power isn't cheap. The LPE H2 package will set you back a solid $17,600. Then, of course, you'll want flashy aftermarket wheels/tires (such as the Weld EVO 18x10-inch alloys fitted to this test vehicle), which will add another couple thousand to the grand total. But the price will be well worth it the first time you blow the doors off an unsuspecting musclecar.