General Motors' small-block V-8s are the Rolling Stones of engines. Over the last six decades, nearly 100 million of them have been built to power cars and trucks sold by eight American GM brands plus a slew of race cars, hot rods, boats, and a few homebuilt aircraft. To keep a thumb on the small-block's pulse, we gave a pair of them a run through our rigorous test regimen.
When suburban-Detroit-based Jeff Nowicki needed more vitality for his Specter Werkes/Sports Corvettes, he dipped into the bottomless well of small-block parts and expertise. On the outside, the Corvette GTR looks like an action toy from the Transformers 2 movie. Under its swollen and slotted hood beats a heart that sounds like a transplant from a Sprint Cup racer. Stand clear while two Michelin radials are disciplined for misbehavior.
The Nowicki name has been part of the Corvette family for two generations. Jeff's father, Ron Nowicki, was the chief engineer in the Corvette design studio during the C4 and C5 eras. Jeff has worked as a clay modeler and raced Camaros, and he established his own tuning business twenty years ago. Add to that fifteen or so years of campaigning Corvettes in various road-racing series. Today, ten Specter Werkes employees convert standard production models into radical customs with vastly improved performance. Last year, eight GTRs rolled out of this Troy, Michigan, shop with a fresh lease on life.
The Specter Werkes GTR is the rich man's Z06. A base Corvette coupe is reskinned with eleven hand-laid fiberglass panels and seven molded-carbon-fiber components, and it is then sprayed with the same mercury-silver paint that Mercedes-Benz applies to the SL65 AMG. Chassis modifications include a one-inch-lower ride height, Forgeline three-piece wheels, Michelin PS2 run-flat tires, Hotchkis antiroll bars, and StopTech brakes. The GM 6.2-liter LS3 V-8 is fortified with a forged crankshaft and pistons, billet connecting rods, a wilder cam, higher-flow fuel injectors, and an LS7 clutch and flywheel. A three-eighths-inch-longer stroke bumps displacement to 6.8 liters. According to the chassis-dyno report card, 510 hp and 480 lb-ft of torque are delivered to the GTR's 335/30YR-20 rear tires.
Inside, the door panels, seats, steering wheel, and console are trimmed in Spinneybeck leather embossed with an exotic reptile grain. The entire GTR treatment costs some $69,000, or about ten percent less than a new Z06. But before you split your piggy bank, don't forget to add the cost of a core Corvette coupe or convertible.