This Little-Known Corvette From 1988 Is Faster Than A Brand New Tesla
Renowned American tuner and engineering specialist Callaway Cars has an exciting history built on a passion for speed. The company was established in 1977 by Ely Reeves Callaway III (son of Ely Callaway Jr., founder of Callaway Golf) in Old Lyme, Connecticut. Callaway started by making turbocharger upgrade kits for European brands like BMW, Volkswagen, Mercedes-Benz, Audi, and Porsche.
However, Callaway's insatiable appetite for speed goes back to the early 70s when Reeves Callaway, who was then a driving instructor at the Bob Bondurant Racing School, convinced BMW to tune the school's 320i. According to Car and Driver, BMW agreed, and Callaway wasted no time making a custom turbocharger for the car. Callaway loaned the vehicle to C/D's Don Sherman and gave it an excellent review in a two-page article. The fortunate turn of events led to the founding of Callaway Turbo Systems and Callaway Cars in 1977.
From Bimmers to Vettes
Callaway shifted his attention to modifying America's favorite sports car, the Chevy Corvette, particularly the C4 variant produced from 1984 to 1996. And by the time the C4 Corvette came to market, the Callaway speed shop already had a reputation for turbocharging and bonkers performance. And true to form, Callaway wasted no time crafting a twin-turbocharger upgrade for the C4 Corvette.
Recognizing early on the potential of Callaway's custom-made engine upgrades, Chevrolet gave Callaway Cars the blessing to produce tuned versions of the C4 Corvette that came with a standard manufacturer-backed warranty. According to IMSA, customers could order a 1987 or later C4 Corvette with over 390 horsepower, 150 more than the car's stock 240 horsepower output. All vehicles would wear an RPO B2K serial number, complete with a factory warranty and a separate warranty from Callaway.
As expected, enthusiasts came in droves, leading Callaway to draw out its most ambitious project: The Sledgehammer, a 1980s Corvette that could go faster than a modern Tesla EV.
Callaway Sledgehammer: The most potent C4 Corvette
In 1998, Callaway created the world's fastest street-legal Chevy Corvette. This understated monster would smoke any exotic sports car from the same era, including big names like the Porsche 959 and Lamborghini Countach. It starts with a standard Chevy C4 Corvette equipped with a 5.7-liter "Bowtie" V8 and heads to the stratosphere. The list of engine mods includes a custom blueprinted block with align-bored journals, four-bolt bearing caps, Brodix aluminum heads, forged Mahle pistons, a Cosworth crankshaft, MSD ignition, a Zytek ECU, and a bespoke dry-sump lubrication system.
Of course, Callaway installed a pair of Turbonetics T04B turbochargers to sweeten the deal. The result of all this engine wizardry is 880 horsepower and 772 lb-ft of torque, nearly double what you get from an uber-expensive Lambo or Porsche. All that grunt is sent exclusively to the rear wheels via a Doug Nash manual gearbox (per Bring a Trailer) with a bespoke Centerforce clutch pack, a 3.54:1 final drive rear axle ratio, and solid forged aluminum rear half shafts.
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The high-strung V8 engine breathes through custom 321 stainless steel exhaust tubing connected to SuperTrapp adjustable mufflers and four badass center-mounted exhaust tips. Remember, this was in the late 1980s when emissions were merely an afterthought. Other mods include 17-inch Dymag one-piece magnesium wheels (wrapped in sticky Goodyear tires), upgraded brakes, and a bespoke AeroBody shell courtesy of Paul Deutschman.
Speed Demon
Reeves Callaway drove the Corvette Sledgehammer from Connecticut to the Ohio Transportation Research Center in 1988 to test the car. Callaway gave way to John Lingenfelter (yes, the John Lingenfelter, founder of Lingenfelter Performance Engineering), and he pushed the Sledgehammer to the limit around the test center's 7.5-mile oval track.
The Callaway Chevy Sledgehammer managed a top speed of 254.76 mph, numbers that were unheard of in any production vehicle. The insane Tesla Model S Plaid has a 200 mph top speed, so it's mind-boggling that a 35-year-old Corvette could go faster than that. What's more impressive is it came with standard air conditioning, power windows, power seats, and an audio system – all the niceties expected from a stock C4 Corvette.
Bring a Trailer
The Callaway Chevy Corvette Sledgehammer sold for $221,400 at the 2004 Barret-Jackson auction (per IMSA) before resurfacing in 2014 with a $600,000 no-sale at the Mecum auction. It recently surfaced in 2021 at Bring a Trailer with a $500,000 bid price, but the numbers were insufficient to make the reserve. The Sledgehammer held the unofficial speed record for over 20 years, and it wasn't until 2007 when the SSC Ultimate Aero surpassed Callaway's record with a 255.83 mph top speed. More importantly, only one Sledgehammer exists, and we reckon that makes it a unicorn in the performance car realm.