There’s nothing quite like a surprise at a birthday party. On April 24, 2009, at the National Corvette Museum’s C5/C6 Registry Birthday Bash, GM officials floored the audience with the unveiling of the 2010 Grand Sport Corvette. The last time we saw a Grand Sport was more than 13 years ago, in 1996. Times were very different then, as the C4 was making its last appearance. Spy photos of the C5 were all over the car magazines, so Chevrolet’s challenge was maintaining customer interest in a car that was in its final year of production. The solution came in two parts: the Collector Edition—a special paint-and-trim option—and the stunning Grand Sport model. The Admiral Blue Grand Sport—with its white center stripes, red hash marks, black wheels, and other assorted details—was an instant classic. Production was limited to just 1,000 units, and the $3,250 price made it the most expensive option for the ‘96 Corvette. But after six years of the $31,000-plus ZR-1 package, the Grand Sport seemed like a bargain. Since then, the C4 Grand Sport “look” has been applied to all sorts of Corvettes, with many delightful results.

But the Grand Sport story goes back much further than 1996. In fact, it stretches back 34 years, to late 1962 and a test session at Riverside Raceway. It was there that a disheartened Zora Arkus-Duntov saw his latest effort come up short against a formidable new challenge: the Shelby Cobra. Duntov and his team were “field testing” a new ’63 Sting Ray equipped with their latest racer kit, the Z06 option. Since 1957 Duntov had made sure that Corvette racers had an excellent foundation for competition. The 283 fuelie engine provided plenty of grunt, while RPO 684 provided suspension and braking improvements. The package was very successful and was the foundation for Corvette dominance in several SCCA racing classes. Duntov was very happy with the performance of the Z06-equipped ’63, thanks to a new frame that allowed the engine and driveline to sit lower, improving the car’s center of gravity. The four-wheel independent suspension was far superior to the earlier layout, which was described by many racers as, “stab ‘n’ steer.” While most drivers were able to adjust their driving style to fit the Corvette’s unique handling characteristics, it was still a crude way of getting around the track. Many a track official had his wits scared out of him by a Corvette coming around a curve sideways, seemingly out of control. But the presence of the Cobra stopped the new Corvette in its tracks. Duntov and his crew had expected to be several steps ahead of the competition with their new car. Instead, they found themselves seriously outclassed. But Duntov always had another plan.

What happened then could never have taken place in the modern era. Fortunately, Duntov had very powerful friends at the top of GM’s food chain—namely, Ed Cole and Semon “Bunkie” Knudsen. It was Cole who hired Duntov in 1953 with instructions to do something with the fledgling Corvette. And although Knudsen was the son of William “Big Bill” Knudsen, the man responsible for GM’s quick turnaround during the war effort in 1940, he was no privileged rich kid. Knudsen learned the car business from the bottom up, working on the assembly line during his summer breaks from college. He also liked fast cars and was solidly behind Duntov’s racing efforts, so he understood the Corvette chief engineer’s dilemma with the new Sting Ray and the quicker Cobra. The obvious solution to level the playing field was to build a lightweight Corvette. Knudsen agreed and approved Duntov’s ambitious plans for the Grand Sport model. While the move might not seem like a big deal today, in 1962 GM was on board with the infamous AMA ban on factory-supported racing. The Grand Sport proposal was in direct violation of the ban and ran counter to GM’s official position. Duntov knew it, and Cole and Knudsen looked the other way.

Knudsen approved the construction of six lightweight Corvettes of Duntov’s design. After the six initial cars, 125 more Grand Sports were to be built to qualify for FIA homologation. Another 1,000 units would be produced for public consumption.

Duntov started with what was then a state-of-the-art ladder-type frame made from large-diameter steel tubing. The front suspension was similar to, but much lighter than, the stock Corvette setup. The rear suspension used the new Sting Ray independent design, but with an aluminum differential and drilled-out trailing arms. Girling disc brakes were used with Halibrand lightweight magnesium wheels and contemporary racing tires. The body was very close to the production Sting Ray, but used much thinner fiberglass. The final weight of the new Grand Sport was around 2,000 pounds. Duntov had several exotic small-block engines in development, including one with hemi-style heads, another with double overhead cams, and even an all-aluminum fuelie. But none of Duntov’s exotic engines were anywhere close to being ready for competition, so a slightly modified 360hp fuelie was installed for initial shakedown runs. The first versions of the car looked almost stock, but by the time the Grand Sports arrived for the Nassau Speed Week races, they had a full complement of flares, scoops, and fat tires. The cars looked tough and pounded the Cobras. Then GM’s top brass found out and killed the program—officially, anyway.

It’s amazing that Duntov wasn’t fired on the spot, but as I mentioned earlier, he had friends in high places at GM. Even more amazing was that the cars were not sent to the crusher. Grand Sports 003, 004, and 005 boasted 377ci aluminum small-blocks that breathed through four 58mm Weber carbs each and made 485 hp. Cars 001 and 002, meanwhile, had been converted to roadsters. When GM discontinued the program, the cars began passing from racer to racer, as various privateers tried to make the Grand Sport into a serious competitor. But the mid-’60s were a time of tremendous advancement in race-car technology, and in just four years, the Grand Sports were seriously outdated. They had numerous problems that were never fully sorted out, including a terrible front-end lift that would occasionally pull the tires off the ground at high speed. Many famous drivers spent time behind the wheel of a Grand Sport, including A.J. Foyt, Augie Pabst, Jim Hall, Dick Thompson, and George Winterstein. In 1967 Alan Sevadjian bought one of the cars for just $7,500. By the 1970s the Grand Sports were all but forgotten and their whereabouts mostly unknown. The cars began to surface in the late-‘70s, and today all five are accounted for. In January 2009, at RM’s Automobiles of Arizona, Grand Sport 002, one of the two roadsters, was a no-sale at $4.9 million.

Fast-forward to 1996, and the revival of the Grand Sport option. Obviously the C4 edition couldn’t be a lightweight, tube-chassis racer. But it was an extremely well-executed collection of off-the-shelf parts. Under the hood was the new LT4 engine, an enhanced version of the base LT1 that made an additional 30 hp (up to 330 total) with basic hot-rod hardware. These included a higher (10.8:1) compression ratio, new aluminum heads with bigger ports and valves, a revised camshaft, Crane roller rocker arms, and higher-flow fuel injectors. The new engine redlined at 6,300 rpm and had an 8,000-rpm tach. All 1,000 Grand Sports were painted with Admiral Blue paint and had a wide white stripe that ran from the nose to the tail. The ZR-1–style 17-inch wheels were painted black, and flares originally developed for the Japanese export market were installed on the rear fenders. As a salute to the Grand Sport racers, red hash marks were applied to the left front fender. The Z51 suspension option was available to stiffen up the car’s handling. Of the 1,000 cars built, 810 were coupes and 190 were convertibles. (The latter didn’t have the wider tires and the rear fender flares.) Priced at $3,250 for the coupe and $2,880 for the droptop, option Z16 became an instant classic. These days, show organizers like to put all the C4 Grand Sports together in rows, where they make for a dazzling presentation.

The C6 Grand Sport is a completely different animal. The base LS3 engine produces 430 hp—100 more than the old LT4. The new option fits neatly between the base Corvette and the Z06 and is available on both coupe and convertible models, in all color combinations. Oddly enough, the signature fender hash marks are optional. Perhaps most notable are the Z06 body panels, which include front and rear flared fenders, a front air-splitter, and a rear spoiler. The rear brake-cooling scoops are functional, but the front nose scoop is not. Visually separating the Grand Sport from the Z06 are a set of revised front-fender vents, with their ’67-inspired vertical slats. Model-specific five-spoke wheels are available in silver, Competition Gray, or chrome. The fronts measure 9.5 x 18 inches and are shod with Goodyear F1 run-flat tires sized 275/35ZR18. The 12 x 19-inch rears, meanwhile, get massive 325/30ZR19s. The front brakes have been enhanced with cross-drilled 14-inch front rotors and six-piston calipers, while the rears boast 13.5-inch rotors with four-piston binders. All four calipers are painted silver and wear red “Corvette” lettering.

Since the Grand Sport replaces the Z51 Performance Option, all of the Z51 goodies—heavy-duty springs, shocks, and stabilizer bars, along with coolers for the engine oil, transmission fluid, and steering fluid—are included. Additionally, all six-speed manual cars come with the Z52 option, which adds a dry-sump oil system, a rear-mounted battery, and a differential cooler. Manual cars also receive a new launch-control system. This system allows the driver to simply floor the gas, at which point the computer automatically selects the optimum launch rpm. All that’s left for the driver to do is drop the clutch and start shifting. All of the standard Corvette options are available on the Grand Sport, including four trim packages and the Dual Mode Exhaust System. Priced at $55,720 for the coupe and $59,530 for the convertible, the new Grand Sport is still around $15,000 less than a Z06. Zero-to-60 times clock in at 4 seconds flat, with quarter-miles in the low 13s or better. The car generates 1.0g on the skidpad and has an EPA rating of 26 mpg on the highway. Top speed is between 185 and 190 mph, making the latest Grand Sport faster than even the old racing versions.

For at least the first 20 years of its existence, the Corvette was always a hair’s breadth away from being canceled. Thanks to dedicated engineers like Duntov, McClellan, Hill, Juechter, and many others, the C6 Grand Sport can take its place among the greats of Corvette history. KST

Here's the story:
lllustrated Corvette Series No. 19 - 1963 Grand Sport Corvette
"Chevrolet's Cobra Killer"

The 1963 Grand Sport is undoubtedly the ultimate "could-have-been" Corvette. Had GM not pulled the plug, this 2,100 pound monster could have been a true snake-killer. But it wasn't to be.

Grand Sport's problem wasn't a lack of hardware or technical assistance, it was political. The problem began with the 1957 Automobile Manufactures Association ban on factory supported racing. At first, Ford, GM and Chrysler complied, but by 1960 Ford and Pontiac were developing racing programs despite the AMA ban. In June of '62, Ford and Chrysler announced that they would ignore the AMA ban and openly develop racing programs. At Chevrolet, Zora Arkus-Duntov was watching.

Zora figured that if Pontiac was developing the Super Duty program and other groups in Chevrolet were developing the Mark II Mystery Motor, he should be working on a real racing version of the 1963 Stingray. This car would be homologated in the FIA as a GT Class production car.

To be "legal" in the FIA, Chevrolet had to make at least 100 cars to qualify as "production cars." Unfortunately, only five coupes were built. Years later, two were made into open roadsters. The target weight was 1,900 pounds with an all-aluminum 377 small block making 550 horsepower! This was a 180 mph Corvette. Everything was strictly racing!

The body was almost stock except for the nose and rear window. After its intial outing in '63 the G.S. grew all sorts of flairs, scoops and bulges. Under the thin fiberglass body was a twin tube chassis with a stock independent rear and hand made front suspension. The interior looked stock, except for the racing bucket seats, roll cage, and 200 mph speedometer! The car's best effort was the 1963 Nassau Speed Week where they stunned the Shelby team and won!

GM gave all racing programs the axe in January 1963. The Grand Sports were sold and raced independently. Lacking real factory support, they were quickly obsolete by 1966. All five cars have been fully restored. - KST

Here's the story:
lIlustrated Corvette Series No. 20 - 1963 Grand Sport Corvette Roadster
"Chevrolet's Cobra Killer - Part II"

Road racing in America went through a tremendous growth period during the mid-'60s. A competitive race car could be obsolete in only two years. Duntov and his crew secretly designed and built five Grand Sports early in 1962. The three Grand Sport Coupes got enough attention at their debut race in Nassau, that GM brass ordered the program halted.

The three coupes were sold in 1964 and the two roadsters were supposed to be sent to the crusher. Somehow, Duntov managed to avoid that fate. In 1965 one of the roadsters surfaced at a car show at Notre Dame University. Someone in the press quipped that a Grand Sport with the new 427 NASCAR engine might be an interesting race car. Enter Roger Penske.

Penske was planning to race a 427 Coupe that year and added the two remaining Grand Sport Roadsters to his team. Assisting in the preparations was veteran Corvette racer, Dick Guldstrand. The team knew that the Grand Sport was getting tired, but it was too tempting to pass up. Guldstrand supervised the complete rebuilding of one of the roadsters and the necessary changes required for the Traco Engineering-built, 500-horsepower, 427 engine.

By the time the Grand Sport Roadster made it to Sebring in March 1966, the car was seriously outdated. But it was a valiant effort that might have had a chance with some factory support. The biggest problem was still the suspension and it's infamous front end lift.

Driver Delmo Johnson was quoted as saying, "As far as I'm concerned, if any driver ever says he had complete control of that car, he's lying to you." Between the front end lift and the power from the 427, Roger Penske said, "It was so light in the front end that when you really stood on the gas, the front end would come off the ground like a dragster."

Power was not a problem for the roadster. During practice, Guldstrand reported that he could easily blow off even the Ford Mark II cars. A. J. Foyt got dusted by a Grand Sport and was quoted as saying, "What's in that damn dinosaur? It went by me like I was stopped." During actual racing, the car was embarrassingly inadequate.

Penske sold roadster 001 to John Mecam and roadster 002 to George Wintersteen who raced the car unsuccessfully and later sold it for $6,700. George still regrets the sale.

The Grand Sports were the ultimate "could have been" racing Corvettes. Completely lost in the '70s, they have all been found and restored. - KST

Here's the story:
Kit Car Profile No. 8 1963 Grand Sport Corvette
"The Ultimate Could Have Been Corvette"

The 1963 Grand Sport is arguably the ultimate "could-have-been" Corvette. Had GM not pulled the plug, this 2,100 pound monster could have been a true snake-killer. But it wasn't to be.

Grand Sport's problem wasn't a lack of hardware or technical assistance, it was political. The problem began with the 1957 Automobile Manufacturers Association ban on factory-supported racing. At first, Ford, GM and Chrysler complied, but by 1960 Ford and Pontiac were developing racing programs despite the AMA ban. In June of 1962, Ford and Chrysler announced that they would ignore the AMA ban and openly develop racing programs.

At Chevrolet, Duntov was watching. Zora Arkus-Duntov figured that if Pontiac was developing the Super Duty program, and other groups in Chevrolet were developing the Mark II Mystery Motor, he should be working on a real racing version of the 1963 Stingray. This specially developed, all-out race car would be homologated in the FIA as a GT Class production car.

To be "legal" in the FIA, Chevrolet had to make at least 100 cars to qualify as "production cars." Unfortunately, only five coupes were built. Two years later, two were made into open roadsters. The target weight was 1,900 pounds with an all-aluminum 377 small-block making 550 horsepower! This was an all-out, strictly racing, not-meant-for- public highways, 180-mph Cobra eater!

The body was almost stock except for the nose and rear window. After its initial outing in '63 the G.S. grew all sorts of flairs, scoops and bulges. Under the thin fiberglass body was a twin tube chassis with a stock independent rear and hand made front suspension. The interior looked stock, except for the racing bucket seats, roll cage, and 200 mph speedometer! The car's best effort was the 1963 Nassau Speed Week where they stunned the Shelby team and won!

GM axed the car in January 1963. The Grand Sports were sold and raced independently, and are now fully restored. Kit versions are so right on, it's easy to mistake a replicar for the real thing. However, replicars can be made streetable. - KST