With Callaway Cars and Holley recently announcing a new partnership, it’s the perfect time to look back at one of Callaway’s most legendary creations. Long before today’s hypercars normalized 200-plus mph speeds, a coachbuilt C4 redefined what a street-legal car could do. That car was the Callaway Sledgehammer Corvette.

Building A Record-Breaker

The project started with a 1988 Corvette, but the engine that emerged was a completely different beast. Callaway based the build on a NASCAR-spec 5.7-liter V8 block and filled it with the best parts money could buy, including a Cosworth forged crank and Mahle forged pistons. Brodix aluminum heads and a custom cam improved breathing, while a dry-sump system handled the oiling. The stars of the show were a pair of Turbonetics T04B turbochargers and massive intercoolers, forcing up to 22 psi of boost into the engine.

More Than Just An Engine: The Callaway Sledgehammer Corvette

The pros at Callaway knew that horsepower alone wouldn’t be enough. To handle the power and speed, they fitted a ZF six-speed manual transmission and Koni shocks to the lowered chassis. The Callaway AeroBody kit transformed the car’s body with a functional but quirky-looking set of panels that the company designed with extra nostrils and vents to cut through the air and keep the monster engine cool. To put the power down, Callaway tasked Goodyear with creating one-off tires rumored to have cost a million dollars to develop.

The Drive, The Record, The Drive Home

In 1988, the legendary John Lingenfelter got behind the wheel to prove what the car could do. In a move that cemented the Sledgehammer’s legacy, he didn’t put it on a trailer; he drove it from Callaway’s headquarters in Connecticut all the way to the Transportation Research Center in Ohio. There, he hit a top speed of 254.76 mph, a record that stood for nearly 20 years. This proved the Callaway Sledgehammer Corvette wasn’t just a stripped-out racer. After setting the record, Lingenfelter simply turned the car around and drove it back home with the air conditioning on.

A Legend In Hiding

Today, the Sledgehammer lives a quiet life. After selling on Bring a Trailer for $500,000 in 2021, it now sits in a private collection and is rarely seen in public, reportedly still on its original tires. While it’s being preserved as a piece of history, many enthusiasts hope this incredible car gets another chance to be displayed for all to admire.