It wasn't long ago--maybe five or seven years--that a street car with700 rear-wheel horsepower was still the stuff of urban myth.
Sure, you'd hear about them: that car that showed up only once or twiceduring the summer to wipe the street with other local hot shoes, collectsome cash, and disappear into the night. Nobody really knew who thedriver was or what was under the hood, but hey--it had to be makingsomething like 700 to the tires. Hell, as such stories go, it probablyeven had an air-shifted transmission out of what's-his-name's old ProStock car.
With the continuing advances in tuning and increased reliability ofpower-adder systems, 700 "to the treads" in a street car is no longer amyth. It's a cold fact, but that isn't to say it's an easy feat, orcheap.
Mike Leake's sinister-looking '02 Z06, however, certainly looks the partof a sneaky, only-comes-out-at-night street sweeper. Its bad blackpaint, slightly bulged hood, and Hoosier-slick-equipped rear wheelsspeak softly, but communicate the car's capabilities loudly. The whistleof a ProCharger F-1C supercharger has its own voice, too.
Certainly, more than doubling the output over the stock Z06's 405hprating didn't come by treating the LS6 engine to a simple after-catexhaust system and a free-flow air filter. In fact, the factory LS1 wasditched altogether and replaced with a supercharged 427-inch mill basedon the dollar-intensive C5-R racing block. A 4.000-inch-strokecrankshaft, combined with the block's 4.125-inch bores, gives the engineits 7.0-liter displacement.
Beyond size, however, the C5-R block features beefy cylinder liners andthick cylinder walls, along with billet main caps and, compared withregular-production Gen III blocks, a harder alloy that better resistsdeformation in high-horsepower applications. (The decks of regularLS1/LS6 blocks can get a little wavy under load if you pump more than1,000 hp through them, something this combination is on the cusp ofachieving.)
Performance Motors Inc. and MC Racing (www.gomcracing.com) of KansasCity handled different aspects of the engine build, which includedinstalling a set of AFR 225 Mongoose cylinder heads. The high-flow headsboast 72cc chambers, 2.02-inch intake valves, and 1.60-inch exhaustvalves. A stock intake manifold plugged with 72-pound low-impedanceinjectors sends air and fuel to the heads, where it's compressed by acustom set of blower-friendly 8.5:1 Wiseco pistons.
The ATI ProCharger F-1C, with its 4-inch inlet and 3-inch outlet, isdesigned to make more than 30 pounds of boost, enabling engine output ofabout 1,250 hp. Leake's engine is almost there, putting down 772 hp tothe wheels or just about 1,000 ponies at the crank. The Vettecomplemented its 772-rwhp rating with 764 lb-ft of torque to the tires.
By the way, simply keeping this supercharged Vette's rear planted on thedyno was a feat that required more than a couple of husky guys sittingchummily beneath the rear hatch--and the car still wanted to walk offthe rollers.
Ensuring the fuel for the nearly 1,000-horse 427 is portioned outprecisely is the job of an ACCEL/DFI controller, which works with aspeed-density-type air-metering system. There are other supportingcharacters, too, including a Lingenfelter-supplied fuel pump, an MSD"boost-a-pump" fuel-pump "amplifier," and a thick C&R aluminum radiator.