When twin-turbo Corvettes came from the Chevy dealer

Callaway Corvettes were groundbreaking cars. Some might say definitive. Callaway Engineering was, in fact, the first outside supplier to provide General Motors with equipment packages that earned the full factory blessing of a Regular Production Option. The RPO B2K Twin Turbo, introduced in 1987, gave the Corvette a high-performance engine package, compliant with all regulations, that filled in during the four-cam ZR-1’s long development.

With 345 horsepower and 465 pound-feet of torque, it was one of the most exhilarating Corvettes ever built.

It also was an expensive option: $19,995 in 1987—two-thirds the price of the base Corvette—rising to $33,000 by 1991, a few dollars more than the base price of a Corvette coupe.

About 500 B2Ks were built, and they still have a loyal following, particularly when combined with the Callaway AeroBodies, designed by Paul Deutschman, or as the few very special Callaway Speedsters.

When I worked for Callaway in the mid-‘90s, we responded to owners’ inquiries about value with a simple formula: Take the current value of the underlying Corvette, considering its condition and use, and add back the original cost of RPO B2K. That still applies today, although condition and age have become issues that factor importantly—sometimes negatively—into the equation.

Those qualifications, however, wouldn’t seem to apply to the 1987 Callaway Twin Turbo sold at a Mecum auction in Portland, Ore., last June. Reportedly carefully stored since new, it was described as having just 25,800 miles—yet it sold for a mere $15,400. The reason for that low price? It had a Department of Environmental Quality restriction that required it to be sold to an individual or dealer outside of Oregon, which may have deterred local bidders.

Given the quantities in which Twin Turbos were built, it is somewhat surprising that they don’t appear on the public market more often. Perhaps it’s because before the so-called King of the Hill ZR-1 debuted, it was the Twin Turbo that ruled.

The introduction of electronic port fuel injection on the 1992 Corvette brought the next generation of Callaways: the 383-cid stroker LT1 Callaway SuperNatural Corvette. Built for four years, SuperNaturals have faded from view in the public marketplace, but they marked the beginning of a significant evolution for Callaway. From its earlier focus on specific component upgrades, Callaway shifted to a more complete package with integrated power, handling and Deutschman-designed bodywork.

The next Corvette specials were the rare 600-plus-horsepower Callaway C12 models. (Callaway’s numbering system includes other engineering projects like the Aston Martin AMR1 engine development, called C5, the C9 Impala SS and the C11 Range Rover 4.6 HSE.) A C12 claimed the GT-class pole at the 24 Hours of Le Mans in 2001, and a measure of its rarity and appeal is that only four have appeared for public sale. The most recent was Mecum’s sale of the ex-Otis Chandler C12 Speedster at Monterey in 2011 for $95,400.

More recently, the C16 was built upon the C12 concept with new Deutschman-styled bodies on an extensively developed sixth-generation Corvette platform. It was offered as both a coupe and cabriolet. Barrett-Jackson sold an eye-catching Tangelo Orange Cabriolet at Scottsdale Auction Week this January for $115,500. With 616 supercharged and liquid-air intercooled horsepower, it is firmly in supercar territory. Expensive, yes. But what supercar isn’t?