WSC60 Corvette Grand Sport

3d Model Conversion by: Big FAT Luke

The Grand Sport was a direct development of the 1958 FIA ruling that limited international sports/racing cars to three liters engine displacement. Up until that moment, Chevrolet had been hard at work on some exotic big-engined sports/racers, the last of which, the Corvette SS, ran at the 1957 Sebring race in the hands of Piero Taruffi and John Fitch.

Seeing no benefit to passenger-car engineering in perfecting a 3-liter racing engine, Chevrolet stayed away from road racing until their resident competition wizard, Zora Arkus-Duntov, spotted a loophole in the FIA rules that would permit Chevrolet's return.

Because no displacement limits were set on GT cars, Duntov and his talented design group set out to build a lightweight, big-engined Grand Tourer that would be powerful enough to win not only the GT class, but also the supposedly faster sports/racing category as well. The goal was no less than an overall victory at the Le Mans 24-hour classic.

Chevrolet, still shying away from an all-out racing car disguised as a GT car, wanted their Grand Sport to look like a production car - in this case, their brand new Sting Ray. Duntov and his Corvette engineers reckoned that it would take 600 horsepower to push the Sting Ray up the straight at Le Mans at a competitive top speed, 4-wheel disc brakes to slow it down, and a vehicle weight of 1800 lbs. to achieve competitive lap times.

In 1962, Zora Arkus-Duntov initiated a program to produce a lightweight version based on a prototype that mirrored the new 1963 Corvette. Concerned about Ford and the Shelby Cobra, Duntov's program included plans to build 125 examples of the Corvette Grand Sport to allow the model to be homologated for international Grand Touring races. After the GM executives learned of the secret project, the program was stopped, and only five cars were built. All five cars have survived and are in private collections. They are among the most coveted and valuable Corvettes ever built, not because of what they accomplished, but because of what might have been.

The cars were driven by famed contemporary race drivers such as Roger Penske, A. J. Foyt, Jim Hall, and Dick Guldstrand among others. Dick Thompson was the first driver to win a race in the Grand Sport. He won a 1963 Sports Car Club of America race at Watkins Glen on August 24, 1963, driving Grand Sport 004.

The Corvette Grand Sports were raced with several different engines, but the most serious factory engine actually used was a 377 cubic inch displacement, all-aluminum, small block with four Weber side-draft carburetors and a cross-ram intake, rated 550 hp (410 kW) at 6400 rpm.

Body panels were made of thinner fiberglass to reduce weight and the inner body structure 'birdcage' was aluminum rather than steel. The ladder-type frame utilized large seamless steel tubular side members connected front and rear with crossmembers of about the same diameter tubes. Another crossmember was just aft of the transmission and a fourth one at the rear kick-up anchored the integral roll cage. The frame was slightly stiffer than the 1963 Corvette production frame and was 94 lb (43 kg) lighter. A number of other lightweight components were utilized to reduce overall weight to about 800 pounds less than the production coupe. Initially the Grand Sport project was known simply as "The Lightweight".