The C16's 6.0-liter V-8 is a bundle of nervous anticipation at idle, the result of a polished supercharger and intercooler system that force-feeds the tuned and tweaked innards. Two engine options are available. The base C16 engine is hyped from the stock 400 hp to 560 hp by 7 psi of boost. Step two, which we tested, adds new cylinder heads containing larger valves, machined ports, altered combustion chambers, and new rocker arms. The finishing touch is a more aggressive camshaft. To provide a clear path for Callaway's Honker air intake funnel, the Eaton/Magnuson blower is spun from the rear by an offset belts-and-jackshaft drive system. A heavy-duty clutch and flywheel pass on the 582 lb-ft of torque.
Callaway uses a clever belt-and-suspenders approach to fortifying the C16's suspension. Instead of replacing the factory composite-plastic leaf springs, a coil-shock unit is simply added at each corner to provide the desired higher spring and damping rates, as well as adjustability. Home tuners can alter the ride height, pitch angle, damping (in both directions), roll stiffness, and corner weights. The Eibach remote-reservoir dampers offer twenty click-to-adjust settings, so switching from road to racetrack mode is a snap.
Callaway's Le Mans endurance racing experience taught him the virtues of having powerful brakes. The C16's Alcon stopping system features twenty pistons (six per wheel in front, four each in back) squeezing nodular iron rotors that match the Z06's brawny front-rotor dimensions at all four corners. The exotic Dymag nine-spoke wheels marry forged-magnesium centers to carbon-fiber rims to save approximately 25 pounds of unsprung weight. The ultralow-profile Michelin Pilot Sport tires--275/30YR-19 in front, 325/25YR-20 in back--are, for the time being, placeholders. The larger rear rubber that Yokohama is tooling up for the C16 won't be ready for a year.
Paul Deutschman, Callaway's stylemaster for twenty years, created the C16's voluptuous wrapper, starting with modeling clay added to a 1:10-scale Revell model. The surfaces were transferred to a computer and finished using modern CAD (computer-aided-design) tools. New fiberglass panels cover every square inch of the body except for the roof, the deck lid, and the mirrors, which are stock parts. Rid of the donor Corvette's creases, the C16 looks great. The only major dimensional change is length, which has been increased by 6.8 inches over the stock Z06.
Callaway was able to complete this ambitious makeover in just six months, because GM generously provides digital surface data to legitimate aftermarket users and because the stock Corvette skin is attached to its substrate by screws and bolts. Mustering the courage to purchase expensive molds before any full-scale representation of the finished product existed also trimmed months from the project.