The cars we loved.

1987-1991 Callaway Twin-Turbo Corvette: The First Factory Blessed Super Vette

1989 Callaway Corvette

1989 Callaway Corvette

In the world of mainstream tuners, some associations have become ledgendary. Hurst with Oldsmobile, Shelby with Mustang and Callaway with Corvettes.  Ely Reeves Callaway III actually got his start conceptually with a BMW, but it was the Corvettes that his company has become famous for – twin turbo Vettes to be exact. Other Chevorlets would get the Calloway treatment including the Camaro.

1990 Callaway Vette Interior

1990 Callaway Vette Interior

Callaway Automotive actually has dabbled in many types of performance vehicles. The list includes the likes of VW, Alfa Romero, Mazda, Holden and Range Rover. The relationship with the Corvette has been one of the longest and most consistent. Callaway Cars caught the attention of GM after Callaway developed a twin-turbo system for the Alfa Romero GTV6. GM’s own program to develop turbo systems was winding down after the ideal of V6 and V8 turbo Vetts was rejected. Buick and Pontiac would make use of it. A different route was needed to develop a true flagship Corvette, a route that would take the Chevrolet bass outside of the corporate confines. The invitation was made to Callaway to develop a twin-turbo and the rest was Corvette history. Most of Callaway’s projects before this time were smaller four and six cylinder based projects, but the 345 hp V8 prototype he rolled out in 1986 changed all of that. Needless to say, it impressed GM and excited the motoring press.

Sledgehammer Corvette

Sledgehammer Corvette

Later, Callaway would use a 1988 Corvette for what amounted to a kind of proof of concept that would be known as the SledgeHammer. It was purpose built for a Car and Driver test event, but would also announce the arrival of the Callaway option for the Corvette in a big way. Designed primarily for high speed, it featured aero body design enhancements for stability. The basic look of the Aero Package from the SledgeHammer would find its way into production cars later.

The SledgeHammer would reach a top speed of 231 mph in a Car and Driver test, establishing a record. The specially prepared, heavily modified engine had 898 hp, but came with all the features of a regular street going Corvette including air conditioning, power windows/locks and of course a booming stereo. The SledgeHammer also demonstrated Callaways ability to tune a supercar that could be driven around town and idle comfortably in rush hour traffic. As awesome as the SledgeHammer was, it was no precious trailer traveler. After a 254 mph high speed test run in Ohio, the SledgeHammer was driven back to Callaway’s headquarters in Old Lime Connecut.

It was not long after that Chevrolet made the Callaway Twin Turbo an official Corvette option package in 1987 (B2K). While toned down considerably from the SledgeHammer, it was still impressive and managed to get an RPO code and the complete GM warranty coverage like any other new Corvette in the process. With a top speed of 187 mph, the 87 Callaway Corvette was not as fast as the SledgeHammer, but it would be “mass produced” at a price point that was more accessible.  Accessible was relative of course, as the Callaway option added another $20k+ to the cost of a base Corvette. They were available as hardtop coupes or convertibles.

90 Callaway Corvette Convertible

90 Callaway Corvette Convertible

Horsepower figures steadily creeped up to the magic 400 figure. As early as 1988, a few Callaway Corvettes would pump out 420 hp, until emissions issues scaled the power back to 345 with an approved exhaust system.  1989 saw the addition of a sleek front end aero clip in addition to the massaged twin turbo that had passed the 400 hp mark by 1990.  Other tasteful changes were subtle enough to look almost stock, but still announced to on lookers that this was no ordinary Corvette.

The Corvette was already a solid car with a strong chassis designed to accommodate more power than the stock L98 engine. Callaway’s improvements were very factory like in mechanical application and appearance, getting Chevrolets approval at every stage. Even the Dymag wheels were a similar size but were lighter than stock. The interior was pretty much left alone, being almost instiguishable from a stock Corvette. With each year horsepower figures would rise while some options like automatic transmission would disappear in 1990.

1991 would be the final year a Callaway Corvette would be based on the L98 engine. Chevy had rolled out its own version of a super Vette, the ZR-1 which had a similar price and performance. The ZR-1’s arrival and the pending LT1 engine design for the 1992 and beyond would force Callaway to abandon the positive manifold pressure methods it had been using with previous Corvettes. Future power solutions would include increasing displacement. 1991 was also the year Callaway closed its twin turbo Corvette chapter with a lower volume roadster called the Twin Turbo Speedster with a short windshield reminiscent of Porsche’s 911 Speedster.

The naturally aspirated ZR-1 would carry on the ultimate Corvette banner for the next few years.  As a more ‘in-house’ design, the ZR-1 allowed buyers to choose from many more options and color combinations. While there would not be more turbo Callaway Corvettes after 1991, LT1 based cars were called ‘SuperNatural ‘due to their being naturally aspirated. Callaway Automotive produces a full line of products ranging from the Corvette and Camaro to trucks.

1991 Callaway Speedster Corvette

1991 Callaway Speedster Corvette


One comment on “1987-1991 Callaway Twin-Turbo Corvette: The First Factory Blessed Super Vette

  1. E R Callaway
    December 18, 2011

    I wonder if this article shouldn’t be edited to reflect the correct name of the founder. It’s Ely Reeves Callaway III, son of the founder of Callaway Golf, Ely Reeves Callaway Jr. Otherwise not a bad summary of the Callaway Corvette connection of those years. The relationship is intact today, with Callaway versions of the Corvette, Camaro and Sport Trucks available as new cars through Callaway Chevrolet Dealers Nationwide. Only as new cars, and with full warranty.

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This entry was posted on December 18, 2011 by in 80's Cars, 90's cars, Chevrolet, General Motors and tagged , , , , , .
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