[4] With a completely new chassis, modern sleeker styling, and other improvements to the model, prices rose and sales declined.

[5][2] The C4 Corvette represented a clean break from the Zora Arkus-Duntov-designed C3, with a completely new chassis and sleeker, more modern but still evolutionary styling.

Due to a styling decision to use a targa top instead of T-tops, there was no structural member tying the windshield frame to the halo as on the C3.

This required extremely tall side rails on the frame to maintain chassis rigidity, and as a result, the door sills were quite deep, with entry and exit likened by contemporary auto journals to a "fall in and climb out" experience.

[citation needed] The targa top bolted into place, becoming a structural component, rather than simply latching on like T-tops.

[citation needed] The parking brake, located between the door sill and the drivers seat, was moved lower and toward the rear of the car in 1987 for easier entry and exit.

1996 was a high point of small block engines development and the 330 hp (246 kW) LT4 was introduced in all six-speed manual transmission equipped cars.

All were destroyed except one, VIN 1G1AY0783D5100023 (white with a medium blue interior), fitted with a 350 cu in (5.7 L) L83 205 hp (153 kW) V8 engine and a 4-speed automatic transmission.

[citation needed] General Motors acquired Group Lotus, a UK based engineering consultant and performance car manufacturing firm, during 1986.

In addition to the engine, Lotus helped GM design the ZR1's (which in prototype version was called "King of the Hill"[10]) upgraded braking and steering systems.

[citation needed] The ZR1 is fitted with Goodyear Eagle Gatorback tires having size of P315/ 35ZR-17 specially made for the car along with bigger ventilated disc brakes.

The system allowed for six damping settings in each of the three driving modes namely Touring, Sport, and Performance and had 14 total steps.

The crankcase has integral four- and six-bolt cast-iron main bearing caps which secure the forged steel crankshaft into place.

The four camshafts of the engine are driven by a roller chain and actuate hydraulic lifters that eliminate valve lash adjustment.

The four-valve combustion chambers feature centrally-located spark plugs which act in combination with dished aluminum pistons enabling for a compression ratio of 11.0:1.

In order to transfer power efficiently to the rear wheels, a unique 6-speed manual transmission manufactured by ZF was installed with a code name of ML9.

The transmission used Computer Aided Gear Selection (CAGS) which forced the driver to shift from first to fourth under low power urban driving conditions.

[12] The ZR1 was introduced at the 1989 Geneva Motor Show and went on sale later that year and was available only as a fastback coupe bodystyle with a removable roof panel.

Further changes were made the following year in 1991, including extra ZR1 badges on the fenders and the introduction of Acceleration Slip Regulation (ASR) or traction control.

As evidence of this, a stock ZR1 set seven international and world records at a test track in Fort Stockton, Texas, on March 1, 1990, verified by the FIA (Fédération Internationale de l'Automobile) for the group II, class 11 category:[13][14] These records were later broken by the Volkswagen W12, a one-off concept car that never went into production.

Chevrolet approached Callaway to offer such an option after seeing the power output the tuning company was able to extract reliably from modified twin-turbocharged Alfa Romeo V6 engines.

[19][20] A derivative of the Twin Turbo Corvette, the 880 hp (656 kW) Callaway SledgeHammer, recorded a speed of 254.76 mph (410.00 km/h) on Ohio's Transportation Research Center track in 1988, making it the fastest road-going car at the time.

[citation needed] In 1994 twenty five (25) Corvette Convertibles were delivered to the Indianapolis Motor Speedway for use in the inaugural running of the Brickyard 400.

There were thirteen Red and twelve Black convertibles used, and most carried two drivers on the lap, with their names displayed on the hoods.

They also carried civil, NASCAR, and Manufacturer dignitaries on other parade laps, such as "the King" Richard Petty, Bobby Allison, and Mayor Goldsmith of Indianapolis.

-LT1 receives mass air flow (MAF) sequential-port fuel injection (SFI) system to improve engines's responsiveness, iddle quality and drivability.

-LT1 receives new ignition system to reduce start time specially in colder weather -4L60E 4 Speed automatic transmission is now a electronically controlled version of the 700R4.

This final GTP Corvette (Peerless) was driven by Hobbs, Baldwin, Villeneuve and Goodyear in IMSA before having the BBC-based Eagle (10.2) engine installed to take to attempt to race at the Le Mans 24 Hours in 1990.

The C4 also made an appearance in international sports car endurance racing in a project orchestrated by former Corvette Cup driver Doug Rippie.

The car, based on the ZR1 trim C4, competed in the popular GT1 class in 1995 at Le Mans and Sebring, where it momentarily led.