1987 Callaway Twin Turbo Coupe

This car sold for $5,724 at the ICA sale in Gilbert, Arizona, on January 12, 2008. While that isn’t much for a C4 coupe, and it’s beans for a Callaway car, I reckon this one was very well sold and unfortunately bought.

When car guys get together, performance—or more specifically, horsepower, torque, and time-distance discussions—almost always come up. I know this is true with Corvettes, and the Callaways hold some of the most impressive records for horsepower, speed, and acceleration. In October 1988, it was the twin-turbocharged Callaway Sledgehammer that earned the record for the fastest street legal car in the world—254.76 mph, recorded at Ohio’s Transportation Research Center. It’s a record barely eclipsed only recently. But how and why did the Callaway Corvettes come about?

GM’s outsourced supercar

When Zora Duntov retired as the Chief Engineer for Corvette in 1975, Dave McLellan was promoted to his position. McLellan was tasked with putting Corvette back on the map after years of diminishing performance, styling, fit, and finish. He and his staff knew that unless Chevrolet could give performance car customers what they expected and paid for, the brand was in serious trouble. The result was the C4 of 1984.

In 1985, McLellan contracted with Specialized Vehicles, Incorporated, in Troy, Michigan, to work on two engine platforms for Corvette. One was a twin-turbocharged 350 V8, the other a 90-degree turbocharged V6. Working prototypes of both configurations were designed and built. The V6 would provide extra space underhood for the turbos, plumbing, and heat exchangers, plus get better mileage, but the driveline and rear suspension of the stock Corvette would not accommodate the V6. Perhaps more importantly, marketing figured the buying public would not accommodate the V6.

The V8 design produced well over 400 hp and 500 ft-lb of torque, compared to the stock Corvette, which now put out 230 hp and 330 ft-lb. Don Runkle, head of Chevrolet market planning, suggested to McLellan they share what had been learned at SVI and the Arizona Proving Grounds with Reeves Callaway, whose Callaway Cars aftermarket performance shop had been successful with several marques, especially the Alfa Romeo GTV-6 and various BMWs. GM had the technology and capital, but it would have taken years to get their turbocharged super Corvettes through the EPA. Callaway already had experience doing just that, and through a series of negotiations with McLellan and others at GM, he was awarded an extremely unusual opportunity.

Callaway was given significant financial and engineering assistance, plus warranty coverage (12 months/12,000 miles) directly through GM dealers to provide the Corvette with Regular Production Option B2K as an outside contractor. This was the only time in GM’s history such a thing had been done, and it will probably never happen again.

Concurrently, GM had established a design and engineering contract with Lotus in England to develop the next-generation LT5/ZR-1 powerplant, a 32-valve, DOHC, fuel-injected V8. Though ZR-1 production was still years away, it would ultimately signal the demise of the Callaway RPO option through GM, but the B2K stopgap proved to be a popular and potent fix.

The ’Vette guys stepped up

The base price of a 1987 Corvette was $28,000; the B2K RPO was another $19,995. It was a huge price, but in 1987, 188 people stepped up for one. They came in both convertible (65) and coupe (123) body styles. The majority were ordered directly through annointed Chevrolet dealerships. Callaway also offered the public an opportunity to send their stock Corvettes directly to him for conversion. Those cars got the same upgrade treatment as original, dealer-ordered models.

B2K cars were completed on the Corvette line in Bowling Green, Kentucky, and drop-shipped to his shop in Old Lyme, Connecticut. The original engines were removed and a race-prepared, twin-turbo 350 was stuffed into the car in its place. Power and torque specs were at least 345 hp/465 ft-lb during the first year of production, and the cars had a top speed of almost 180 mph. Every car was road tested by Reeves Callaway to make sure it was ready for the customer.

From 1987 through 1991, Callaway built 520 of his Corvettes. Throughout production, the B2K package changed slightly. Automatic transmissions were not available for the B2K package until 1988, when a re-worked TH-400 truck transmission with a Laycock electronic overdrive became available at the huge cost of $6,500. It was offered for two years. Dymag magnesium alloy wheels became standard equipment, as did heavy-duty suspensions, power-steering coolers, and bigger brakes. In 1990, the Aerobody ground effects package could be ordered. This collection of fiberglass panels was similar to those used on the Sledgehammer and created serious downforce at very high speeds. The panels were never part of the B2K package but an “add-on” available directly from Callaway. They cost thousands of dollars over the option price, and that was before customers had them painted and installed. By the end of production, the B2K option cost had risen to $33,000.

When good cars go bad

Our subject car seems to be the unfortunate result of a very hard life. Sure, the turbos were claimed to have just been rebuilt, but that doesn’t explain the erratic idle. The turbos don’t even spool until about 2,500 rpm. The B2K package added about 3,000 additional parts to a stock C4, so that leaves 2,998 other possibilities. The injectors? The timing

Callaway Corvettes are reliable machines, but they do not suffer deferred maintenance gladly. These are finely tuned, silky smooth supercars, each piece relying on the others to make things happen. There is no piecemeal when you fix one of these things, and there is no cheap way to do it. The proprietary parts are available only from Callaway Cars, and many are no longer stocked. Just replacing the turbos, intercoolers, and mufflers will cost about $10,000, and the sheer volume underhood taken up by all that engine means no repair is easy.

A good B2K car with low miles and maintenance history will fetch between $25,000 and $45,000, though I have seen them sell for more. If I had to guess, I’d say our buyer thought he’d found a steal of a deal. After all, this wasn’t just a Corvette, it was a Callaway Corvette. You don’t see these things every day.

Having owned and driven plenty of good Callaway cars, and based solely on what we know about the car’s overall condition, I have a feeling this car is about to disappear into the deep recesses of a hobbyist’s garage, and it will be a long time, if ever, before it sees the light of day again