view cart menu separator categories menu separator faq
advanced search
categories  > Corvette > C-4 (1984 to 1996) > 1988 (10)
1988 Callaway Corvette Sledgehammer Illustrated Series No. 136

1988 Callaway Corvette Sledgehammer Illustrated Series No. 136

Price: $27.95 add to cart     
Feedback: 100%, 34 sales Ask seller a question
Shipping: US-Mainland: $13.45 (more destinations)
Condition: Brand new
Payment with:
Here's the story on this print:
Illustrated Corvette Series No. 136 - 1988 Callaway SLEDGEHAMMER
"Callaway’s 254.76 Corvette”

While the ‘09 ZR1 is receiving well-deserved kudos for its 200-plus-mph potential, it was nearly 20 years ago that Reeves Callaway and his team smashed the record books with a street-driven twin-turbo ’88 Corvette. The car was appropriately called “The Sledgehammer.”

Yes, the Sledgehammer was a radically enhanced version of an ’88 production Vette. But the operative word here is “production.” This was no one-of-a-kind exotic like the current Guinness World Record–holding Ultimate Aero, built by Shelby Supercars. And the Ultimate Aero’s record-setting average speed was 256.18 mph—not much more than the 254.76 mph achieved by the production-based Sledgehammer.

The reason behind why super-fast cars are built is often just as interesting as how they are built. Plans for the Sledgehammer began after a heavily modified Callaway Twin-Turbo stomped the competition at Car & Driver’s “Gathering of the Eagles” top-speed event in August of 1987. Reeves Callaway drove the car to a winning top-speed of 231 mph. (A production Callaway Twin-Turbo topped of 187 mph.) The high-speed flier was very fast, but it was unacceptably crude for a Callaway. It was rough, hot, smelly, and challenging to drive. So, Reeves began to wonder: Could he build a “real” version of the car?

Later, Reeves was discussing a German article about the 231-mph car with Corvette Chief Engineer Dave McClellan. The article was titled “Des Is Der Hammer.” Referring to the new car, McClellan joked, “Des Is Der Sledgehammer!” The name stuck, and Callaway got to work. Reeves wanted to build a comfortable, streetable 250-mph GT. The modification regimen was relatively simple: engine tuning to produce least 900 tractable horsepower, suspension tweaks for high-speed stability, interior mods for safety, and a body kit to enhance aerodynamics. Drag-racing legend John Lingenfelter was contracted for the engine work. Deutschman Design created the body kit to be stable at 250 mph. Road-racer Carroll Smith was contracted for the suspension work, and Callaway employees Tim Good, Elmer Coy, and Dave Hendricks were assigned to oversee the project.

The 349.8ci, 4-bolt-main Chevy Bowtie block used a cross-drilled Cosworth crankshaft, Crower rods, Jesel roller rockers and stud girdle, and Crane roller lifters. A mild Cam Techniques camshaft kept the engine livable on the street. The Brodix heads were O-ringed with copper gaskets, and studs were used instead of bolts. A Barnes 10-quart dry-sump oil system was also employed. Compression was just 7.5:1, and the twin Turbonetics T04B-Series turbos with stainless-steel wastegates were set at 22 psi. The largest intercoolers available were mounted behind the front bumper, and the turbos were mounted just behind the front grill panels, aft of the front wheels. Callaway-made stainless-steel headers connected to huge-diameter exhaust pipes and SuperTrapp mufflers. It all added up to 898 horsepower!

The suspension was lowered one inch, and the lower control arms were repositioned to reduce bumpsteer. Adjustable Koni shocks controlled dampening. Special high-speed Goodyear tires were mounted on 17 x 9.5-inch Dymag magnesium wheels at the front and back. A Doug Nash five-speed gearbox was built to racing specs and equipped with a special overdrive unit for the final top-speed push. The driveshaft, yokes, and axles were beefed up, and a special Spicer/Dana rear was installed.

The interior was stock except for the leather-covered roll bar, a fire-suppression system, and additional monitoring equipment on the passenger side of the dash. A modified Toshiba laptop PC was used to gather and measure vital statistics.

On October 19, 1988, the Callaway team left for the Transportation Research Center in Ohio. To demonstrate its street-car bona fides, the Sledgehammer was driven all the way to the facility. Once on the 7.5-mile oval track, numerous bugs had to be worked out. A 135-mph misfire was traced to dirty fuel injectors. Then, a minor 198-mph oil leak was discovered and fixed. Nasty weather followed, with heavy rain, wind, and snow flurries. Reeves, who was recovering from the flu, left the driving to John Lingenfelter. On October 26, 1988, with Lingenfelter at the wheel, the Sledgehammer lived up to its name, blasting through the timers at nearly 255 mph.

After some celebration, the team packed up, and the Sledgehammer was driven home to Connecticut. Like Joel Rosen from nearly 20 years earlier, Reeves hoped to build many more of his highly tuned supercars. But priced at $400,000 each, he had no takers. Still, Callaway had bested Europe’s finest and earned yet another place in the Corvette history books.

Printed on high quality tan-colored parchment paper using a Xante professional grade printer.

This print comes in one size:

11” x 17”

Print is shrink wrapped on 11.5" x 17.5" cardboard so that they stay flat and clean and shipped via USPS Priority Mail. All prints are signed by the artist. They make a wonderful gift for the car lover in your life!
Other Products from autoillustrated:View all products
1978 Corvette Coupe Profile
Dandy Dick Landy's Super Stock Dodge Challenger
2004 Commemorative Edition Corvette
1959 Corvette Illustrated Series No. 9
1998 Indy 500 Pace Car Corvette
1990 - 1995 350 LT5 ZR1 Engine
2005 C6.R LeMans Winning Corvette Illustrated Series No. 126
Corvette Z06 Tribute
1957 Fuel-Injected Corvette "Detroit's First Fuelie"
2003 Corvette Coupe Profile
Last Updated: 12 Jun 2014 10:11:35 PDT home  |  about  |  terms  |  contact
Powered by eCRATER - a free online store builder