C4 (1983-1996)

The highly anticipated fourth generation Corvette began production in March 1983 as a 1984 model. The 1983 model year was skipped due to production problems, although 44 prototype 1983 models were completed. All 44 1983 model year prototypes assembled were crushed except for one (the 23rd produced), which is displayed at the National Corvette Museum in Bowling Green, Kentucky. The C4 production started in 1984 and ended in 1996.

The C4 was praised for its sleek styling and its groundbreaking aerodynamic design. The C4 coupe incorporated a rear glass hatch, like the 1982 Collector's Edition, for much improved cargo access. It also had all new brakes with aluminum calipers. The Corvette C4 came standard with an electronic dashboard with digital liquid crystal displays for the speedometer and tachometer. The C4 was a complete and total redesign except for its engine, and the emphasis was on handling. This handling focus came with the penalty of a harsh, uncompromising ride.

From 1984 through 1988, the Corvette used an unusual "4+3" transmission — a 4-speed manual coupled to an automatic overdrive on the top three gears. It was designed to help the Corvette meet U.S. fuel economy standards. The transmission was problematic and was eventually replaced by a much more modern ZF 6-speed manual gearbox in 1989. This new transmission was also the first to feature Computer Aided Gear Selection (CAGS), which used a solenoid to lock out 2nd gear during certain driving conditions. This allowed the Corvette to maintain EPA fuel economy ratings high enough to avoid the "gas guzzler" tax.

Beginning in 1985, the 230 horsepower L98 engine with tuned port fuel injection was installed in most Corvettes, replacing the throttle body fuel injected powerplant. For the 1992 model year, the 300 horsepower LT1 engine was introduced, which significantly improved the performance of the base C4 cars. Also introduced in 1992 was Acceleration Slip Regulation (ASR), a form of traction control which utilized the Corvette's brakes, spark retard and throttle close-down to prevent excessive rear wheel spin, and possible loss of control. The traction control device could be switched off if desired. In 1996, the final year of C4 production, the 330 hp (246 kW) LT4 V-8 was installed in all manual transmission equipped Corvettes; all 1996 Corvettes with automatic transmissions utilized the LT1. The C4's incredible handling characteristics and cornering ability allowed it to dominate SCCA events and races during the 1980s^.

1984 Model Year

This first year model of the C4 carried over the L83 engine from the previous generation of Corvette. The L83 engine had a unique fuel delivery method, named "Crossfire", a dual-throttle-body injection system. The 1984 and 1985 were the only C4's to lack the third brake light (CHMSL, Center High Mounted Signal Light) which was required by federal law beginning in 1986.

B2K Callaway Twin-Turbo

In 1987, the factory B2K option became available from the factory.

The Callaway Corvette was a Regular Production Option (RPO B2K), the only time in Chevrolet's history a specialist manufacturer was entrusted with a technically advanced high performance RPO. The B2K option was eventually replaced by the ZR1 option, though they coexisted from 1990-1991. The early B2K's produced 345 hp (257 kW) and 450 ft·lbf of torque. The later B2K's produced 450 hp (336 kW) and 613 ft·lbf of torque.

(1990-1995)

In 1986, the Corvette team approached Lotus, then a GM subsidiary, with the idea of developing an ultra-high performance vehicle based on the C4 Corvette. With input from GM, Lotus designed a new engine to replace the traditional pushrod L98 V-8 that powered the standard C4. The result was the LT5, an aluminum-block V-8 with the same bore centers as the L98, but with four overhead camshafts and 32 valves. Lotus designed a unique air management system for the engine to provide a wider power band by shutting off 8 of the 16 intake runners and fuel injectors when the engine was at part-throttle, while still giving the ZR-1 375 hp when at wide open throttle.

In addition to the engine, Lotus aided the development of the ZR-1's standard "FX3" active suspension system.

In 1991, all Corvettes received updates to body work, interior, and wheels. The convex rear fascia that set the 1990 ZR-1 apart from the base model was now included on L98 Corvettes, making the styling of the expensive ZR-1 even closer to that of the base cars. The most obvious difference remaining between the base and ZR-1 models besides the wider rear wheels was the location of the CHMSL (center high mounted stop lamp), which was integrated into the new rear fascia used on the base model, but remained at the top of the rear-hatch on the ZR-1's.

Further changes were made in 1992: ZR-1 badges were displayed on both front fenders and traction control was added as a standard feature. In 1993, Lotus redesigned the cylinder heads and valvetrain of the LT5, resulting in a horsepower increase from 375 to 405. In addition, a new exhaust gas recirculation system improved emissions control. Production of the ZR-1 ended in 1995, after 6,939 cars had been built.

Grand Sport (1996)

Chevrolet released the Grand Sport version in 1996 at the end of C4 Corvette production. The "Grand Sport" moniker was a nod to the original Grand Sport model produced in 1963. A total of 1,000 Grand Sports were produced. The 810 coupes and 190 convertibles were produced with a special VIN sequence to differentiate them from the other 1996 C4 models. The 1996 Grand Sport was equipped with the LT4 engine, which produced 330 hp (246 kW) and 340 ft·lbf (461 N·m) of torque. All LT4-powered Corvettes included a Grand Sport nameplate on the engine's throttle body. The Grand Sport came only in Admiral Blue with a white center stripe, distinctive black five spoke wheels, and two red hash marks on the hood above the left front wheel. Interior colors were black and red only. A hardtop option was not available with Grand Sport convertibles.

This article is licensed under the http://www.gnu.org/copyleft/fdl.html "GNU Free Documentation License. It uses material from the http://en.wikipedia.org/wiki/Chevrolet_Corvette" Wikipedia article "Chevrolet Corvette".