1991 Corvette Performance Specs

You're unlikely to find a 1991 Callaway convertible; only 10 remain in existence.corvettes image by michael langley from Fotolia.com

Chevrolet continued the fourth-generation (C4) of its high-performance Corvettes in 1991, a production line it continued until 1996. The company produced the 1991 Corvette in both a two-door coupe and convertible body style. In 1991, buyers could choose from three engines: the RPO ("regular production option") V-8; the enhanced performance ZR1 racing package; or the twin-turbocharged Callaway.

Regular Production Option

Chevy's 1991 Corvette continued utilizing the L98 engine first manufactured in 1984. This eight-cylinder engine with an iron block and aluminum heads had a displacement of 5.7 liters and pumped fuel via a twin-port fuel injection system through two valves per cylinder, for a total of 16 valves. Drivers could choose between a four-speed electronic automatic or six-speed manual transmission. A 1991 RPO Corvette could generate 245 horsepower (hp) at 4,000 rpm and crank out 340 ft.-lb. of torque at 3,200 rpm, and a compression ratio of 9.5 to 1. This drivetrain enabled the 1991 Corvette to accelerate from zero to 60 mph in 5.75 seconds, and run a quarter-mile in 14.36 seconds at 97 mph.

Chevrolet first produced the ZR1 high-performance model in 1989, and the 1991 version continued to use that year's LT5 engine. The LT5 had the same 5.7 liter displacement of the L98 RPO engine; however, unlike the L98, the LT5 consisted entirely of aluminum and employed four valves per cylinder, for a total of 32, valves, and four overhead cams. Drivers could purchase this car with only a six-speed manual transmission. A 1991 ZR1 could crank out 375 hp at 5,800 rpm, 370 ft.-lb. of torque at 4,800 rpm and achieved a compression ratio of 11.0 to 1. This enhanced output gave the ZR1 an acceleration of zero to 60 mph in 4.9 seconds and let drivers hit 108 mph in the quarter-mile in 13.2 seconds.

Although 1991 marked the first time that prospective buyers could order the Callaway Corvette, Chevrolet sold only 62 of these twin-turbo performance monsters in 1991, a featured that added $33,000 to the price. Equipped with the six-speed manual transmission, it achieved a compression ratio of 7.5 to 1. Installation of the twin-turbo took place in Callaway's Connecticut factory, and the upgrade improved the power output of the L98 engine to 403 hp at 4,500 rpm and 582 ft.-lb. of torque at 3,000 rpm. The performance improved dramatically; the Callaway could jump from zero to 60 mph in 4.4 seconds, take the quarter-mile in 12.7 seconds at 113 mph and had a top speed of 191 mph. The convertible "Speedster" edition of this model has become a collector's item, with only 10 remaining in existence.