Introduced to the press at Riverside International Raceway in late 1982, the long-awaited fourth-generation Corvette was stylish, sophisticated, worldly – and unlike any Corvette ever before.

But the excitement didn’t last. Though the 1984 model racked up the second highest build in Corvette history (thanks to a 1.5-year long run), its 51,547 production soon dropped to 39,729 for 1985 and then to 35,109 for 1986. The 350-cubic-inch, tuned-port-injection engines were just not cutting it, and with the four-cam, 32-valve ZR-1 stuck in the developmental pipeline, the Corvette’s relatively low sales compared to other GM models made the company hesitant to further invest in improving the breed.

Unfortunate as the situation was for Corvette, it played out beautifully for Callaway Cars in Old Lyme, Connecticut, which had already been creating high-performance turbocharger packages for different manufacturers. GM became a believer too, after purchasing one of Callaway’s twin-turbo Alfa Romeo GTV6s and discovering that it ran rings around a standard Corvette.

A meeting quickly ensued, and just a few months later, Chevrolet announced a new Corvette option for 1987. Regular Production Option (RPO) B2K specified a 350-cubic inch Corvette V8, with breathing enhanced by a pair of small turbochargers. Even more notably though, it marked the first externally supplied Corvette high-performance package available through participating Chevrolet dealers and covered by a full GM warranty. Times were changing in the competitive arena, and fast.

The Callaway Twin Turbo’s power rating began at 345 hp in 1987 and then grew to 382 horsepower with an astounding 560 lb-ft. of torque for 1989. To handle this massive output, a Callaway-modified GM Turbo 400 automatic replaced the Corvette’s standard 700R4 automatic transmission. The carefully engineered swap included the addition of a Laycock de Normanville-type overdrive unit, as well as integration with the Corvette’s Delco Powertrain Control Module. Despite this trickery, however, only 10 Callaway Corvettes were equipped with the automatic option in 1989, thanks largely to the new availability of the widely heralded ZF six-speed manual transmission.

The finished product was impressive to say the least, with 0–60 times in the mid four-second range, quarter-mile elapsed times in the 12-second range, and top-speed potential approaching 180 mph. Best of all, while these extremely limited-production Corvettes offered supercar-type performance, they were also surprisingly easy to maintain, with everyday drivability. 

This particular 1989 Callaway Corvette has accumulated only 1,055 miles, and it has been owned by discriminating collectors since new. The Bright Red exterior and matching interior are truly stunning and befitting a car with its performance capabilities. Exclusivity is guaranteed, with this car being one of only 69 Callaway Corvettes built in 1989, as well as one of the few equipped with the available automatic transmission. It also includes a rare matching hardtop, as well as other desirable Corvette options. In excellent overall condition, this well-preserved Callaway continues to run and drive as new.

SCM Analysis


Vehicle:1989 Callaway Twin Turbo Convertible
Years Produced:1987–91
Number Produced:68 (1989)
Original List Price:$63,334
SCM Valuation:$20,000–$35,000
Tune Up Cost:$125
Distributor Caps:$12
Chassis Number Location:Lower-left windshield corner
Engine Number Location:Lower rear side of crankcase
Club Info:Corvette Club of America P.O. Box 9879 Bowling Green, KY 42102
Alternatives:1988–89 Corvette Challenge Racer 1991–96 Greenwood Corvette 1990–95 ZR-1
Investment Grade:C

This car sold for $33,000, including buyer’s premium, at RM’s Classic Muscle & Modern Performance Auction in San Diego, California on June 19, 2010.

As noted in the RM auction catalog, General Motors was indeed grasping at straws in trying to make its flagship Corvette a modern competitor in the emissions-strangled 1980s. On sale in early 1983, after a full year’s hiatus since the last third-generation model left the new Bowling Green, Kentucky production line, the C4 platform heralded sweeping changes in design, engineering, manufacturing and complexity. The first models rode very harshly and, as noted, weren’t exactly runaway performance champions right off the train.

To GM’s credit, the company recognized the car’s problems immediately and set about making meaningful changes – ultimately including the Callaway connection. In fact, GM’s sampling of Callaway’s twin-turbo Alfa was certainly not the first time the company had done this sort of thing. True fact: GM also purchased a Porsche 959 to evaluate its potential competitiveness against the upcoming ZR-1, and that car reportedly still exists within the General Motors Heritage Collection.

But while the four-cam ZR-1 was still embryonic, and the prototype mid-engine “Indy Pace Car” or “CERV-III” was barely a fantasy, GM realized it had to fire a salvo of some type to reestablish Corvette’s dominance against various European competitors – as well as the powerful domestic sporty cars such as the Mustang GT. On the dealer lots, the C4’s improved handling, more-attractive styling and even the reemergence of a convertible variant for 1986 was just not enough of a winning proposition.

Callaway/GM relationship historically unique

Callaway’s C4 was very different than hot-rodded Corvette versions from Greenwood and other performance tuners. Simply put, Callaway enjoyed an exclusive vendor arrangement with GM that others could only dream about, and the issuance of a Regular Production Option code, in this case B2K, was not repeated for any other aftermarket performance company.

The cars with this code on their build stickers left Bowling Green with standard powerplants, then landed at the Callaway workshops in Old Lyme for conversion. Here the base-specification L98 was modified for over 10 pounds of boost with twin turbochargers, making a whopping 382 horsepower at just 4,250 revs per minute. This hefty output required either a manual gearbox or, in the case of our auction car, the unusual automatic transmission.

While the entire run of Callaway Twin Turbo Corvettes numbered only 448 (coincidentally the same number as each of the final three ZR-1 production years), its considerable press coverage at least kept Corvette in the footlights of consideration for enthusiasts until the ZR-1 finally arrived. And to its credit, General Motors at least offered a supercar that had Ferraris and Lamborghinis struggling to keep up.

Automatic transmission a serious resale flaw

As with most of the cars offered by RM during the weekend, this particular Callaway has negligible miles from new, and maintains most, if not all, of its original features inside and out. It also benefited from retaining most of its stock Corvette aesthetics, rather than being outfitted with the $6,500-plus Callaway Aerobody kit.

It is also fortunate that the car came with an original auxiliary removable hardtop and most of the other Corvette options available at the time. Still, two important factors held it back from bringing more money. Most important was that the automatic transmission, fancy Laycock overdrive or not, would never be the first choice of most performance drivers. Second, Callaway also did little, if anything, to retune suspensions on the B2K option to match the engine output.

Of late, Corvette enthusiasts have rightfully shown particular interest in highly original cars, especially when one is offered in a true no-reserve auction such as RM San Diego. Price guides tend to be forgotten when bidders realize it may be a very long time before they will have another chance at a car such as this original Callaway.

Languishing national economy or not, the setup seemed right for this Twin Turbo to pull significantly more dollars than it did. Blame this on the plight of the C4 Corvettes in general, because even at 25 years old, they are still far too “new” to be considered classics. But time has a way of taking care of that perception, and as the years roll on the price paid here will very likely ultimately be seen as a bargain.

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