Rare Corvettes · One built

The Callaway Sledgehammer

The most outrageous thing about the Sledgehammer isn't that it ran 254 miles an hour in 1988. It's that afterward, they drove it home. On public roads. With the air conditioning on.

Old Lyme, Connecticut — 1988

By the late 1980s Reeves Callaway's Connecticut shop was already famous for its factory-blessed twin-turbo C4 Corvettes. The Sledgehammer — a single car, build number 51 — was Callaway's answer to a simple question: how fast could one of those cars actually go? The answer was engineered without mercy. Two Turbonetics turbochargers helped the twin-turbo 5.7-liter V8 make a staggering 898 horsepower and 772 lb-ft of torque — and the car kept its radio and air conditioning.

254.76 mph — and then a drive home

On October 26, 1988, with future tuning legend John Lingenfelter at the wheel, the Sledgehammer recorded 254.76 mph on the high-speed oval at Ohio's Transportation Research Center. It made the Sledgehammer the fastest street-legal Corvette in the world — a title it would hold for eleven years — and, because the car was driven to the test and back on the highway, arguably the fastest street-driven car anywhere. The factory ZR-1 was the Corvette's official “King of the Hill” in this same era; the Sledgehammer was the aftermarket's emphatic reminder of what the C4 platform could really do.