A new generation Corvette
The culmination of 30 years of evolutionary engineering was meant to be dedicated to perfecting the complete performance machine. The 1983 was meant to be strikingly new, taut, and thoroughly contemporary. Rather than just being a new Corvette, the 1983 model strove to be a better Corvette. “Or else why change?” Quotes the sales brochure from that year. The goal was a better Corvette from the ground up. Production of the C4 was actually pushed back, from the fall of 1982 to January of 1983, and as a result, the C4 was introduced as an early 1984 model-year car. Chevrolet built a number of prototypes and pilot cars in 1983 to test the fourth generation Corvette before it hit production. Of the 43 prototypes and pilot line cars, only one, a pilot-line car with VIN 1G1AY0783D5110023 remains. This literally one of a kind Corvette and piece of history is on permanent display at the National Corvette Museum.
A most acute windshield rake for a production car: 64. 7 degrees. The ’83 features hidden headlights that tumble forward 158 degrees as they emerge, revealing a lean, aerodynamic shape, for an overall sleek look. Clear, integrated halogen fog lamps. Front and rear side-mounted cornering lamps. Twin Sport mirrors are electrically adjusted and aerodynamically shaped. Body side rub strips are an integral part of the body design. Frameless glass rear window doubles as a hatch, with invisible hinge. Removable one-piece roof, with no T-bar, helps recreate the open-air feeling of sports car past. Four functional circular taillights.
The wind will barely feel the Corvette coming through- the 1983 Corvette had the lowest coefficient of drag of any Corvette ever tested at that time, .341. To achieve this low drag, the car underwent exhaustive wind-tunnel testing in scale model, full-size clay, and prototype stages. New methods of monitoring turbulence as it relates to a moving car were employed. Every line, every curve, every design element was subjected to intensive, aerodynamic scrutiny. And the cockpit, when the roof is off, is remarkably free of annoying airflow disturbances. It efficiently controls captured air to help feed the engine and cool the brakes.
Prepare for Lift-Off- A full-width, one piece fiberglass roof section lifts off to create a true open-air feeling. There is no T-bar in the 1983 Corvette. The advanced aerodynamics of the vehicle help to minimize any turbulence in the cockpit. Also, planned to be available in the ’83 models, at an extra cost, were transparent lift-off roof panels, impregnated with a solar screen, designed to reduce glare.
The Corvette Communication Center- A revolutionary instrument panel was being designed during these years. The 1983 sales brochure boasts “you’ve never seen an instrument panel like this one. At least not in a vehicle designed to remain on the ground.” The new panel featured a multitude of information, all electronically displayed in detail. Multi-colored readouts are displayed by electronic liquid crystals along with analog and digital speed, engine revolutions, and numeric readouts of engine and electrical conditions, fuel consumption and trip mileage data. The new instrumentation strove to be more accurate, immediate, and informative than any of its competitors.
Corvette Shows its true colors- Corvette colors are carefully chosen and applied during a painstaking process. The paint system utilized for the Corvettes in 1983 planned on being one of the most advanced in the world. A new type of paint system with new chemistry and a new multi-step process was designed. First, the body in white (in-mold coated fiberglass) was carefully sanded; then it received a coat of Polane primer. It’s baked, wet-sanded to prepare a smooth surface, primed again, inspected, and spot-sanded to remove any imperfections that could have appeared on the primer coat. All of this occurring before the first color is even applied. The hard work and dedication put into these stages was to ensure perfection in the finished Corvette, something that the employees still take great pride in. The entire paint operation is contained in a dust-free, clean-room environment. The air pressure in this room is maintained positive to keep foreign airborne contaminants from entering. With each of the paint colors, there are two wet-on-wet base coats followed by oven curing. Then there are two wet-on-wet coats of clear enamel, also followed by an oven curing process. To top all of this off, every single Corvette produced would receive a gentle buffing with lamb’s wool-type polishing pads.
Anti-Corrosion Measure- An extensive program was designed to assist the new Corvette withstand the elements even better than any previous model. Fiberglass, the material used in the exterior body panels won’t rust. This Corvette was designed to stand the test of time! The steel under structure of the body is 100% galvanized and dip-painted. As a major anti-corrosion effort the new Corvette features extensive use of aluminum alloys, magnesium and stainless steel. Underbody steel brackets, clamps, clips, braces and retainers are coated or painted to withstand a severe salt spray durability standard. And the steel underbody members receive a special protective coating.
Throughout the conceptual engineering stages, there was a driving determination towards remarkable directional stability, precise on-center steering, transient response and cornering power. The intense dedication paid off, it resulted in an entirely new uniframe structure, light in weight, yet strong and highly resistant to the strenuous flex that can reduce tire patch contact with road surfaces during cornering. The suspension solution, too was re-imagined. Perhaps the most unique feature of the new Corvette is the substitution of a single, fiberglass composite monoleaf transverse spring in the front in lieu of the traditional coils. The unequal length for SLA, for short/ long arm, control arms are of forged aluminum, a design that was computer-generated for minimal weight and extraordinary tensile strength, The knuckles, too, are of forged aluminum. The spindle is offset from the kingpin for directional stability. Telescoping shocks, of course. The suspension has a front stabilizer bar of 24mm and power-assisted rack-and-pinion steering with a 15.5:1 ratio. At the rear, another transverse, fiberglass composite monoleaf spring works within a 5-link independent system featuring forged aluminum knuckles located fore and aft by aluminum upper and lower trailing links and laterally via strut and tie rod assembly. Telescoping shocks are incorporated into the rear suspension, also as is another 20mm stabilizer bar.
Tractive forces are reacted to by a driveline beam of C-shaped aluminum extrusion, which connects from in front of the rear axle and to the rear of the transmission, thus eliminating transmission and differential-mounting cross members. The result is an improvement in driveline strength, greater structural rigidity, and a dramatic savings in weight. Dramatic improvements were registered in tire engineering during the development of the new Corvette. Goodyear personnel worked closely with Chevrolet engineers throughout the car’s development. Goodyear borrowed much from its existing Formula 1 rain-tire technology to create a new kind of performance tire. The optional 16-inch Eagle VR with “natural path” tread is rated equal to the 142-MPH top speed of the new Corvette with 3.31 axle and is of “50” aspect ratio. Once mounted each wheel/tire combination is specific to one side of the car, just like the most sophisticated racing cars.
The 1983 Corvette was designed to brake handily. With a gridlock four-wheel disc brake system, the new Corvette can decelerate from its top speed as high as 1.0g. Gridlock is internationally respected for high performance and racing brake expertise. The low-drag, aluminum caliper design for the new Corvette effects a considerable weight savings over previous Corvette four-wheel disc systems, which helps to reduce unsprung mass. With the standard suspension and the optional Goodyear Eagle VR tires, lateral acceleration is rated at a .9g on the skippad, in the hands of a professional driver. 1.0g is equal to the pull of gravity. Cornering or braking at 1.0g means we are encountering a horizontal component equal in pull to the gravity vector. With Corvette’s .9g reading, the lateral force is equal to 90% of the weight of the car. There is an optional suspension, the Z51 Performance Handling Package. It generates .95g under lateral acceleration on GM’s skippad. Readings in this range were considered remarkable. Despite all these advancements, this model is still a comfortable car to drive. The Z51 incorporates 16″ x 9 1/2″ rear wheels, larger stabilizer bars. 25mm front, 23mm rear. Different bushings are used. allowing low deflection while cornering. There are also differences in the stiffness of the fiberglass monoleaf springs at both the front and rear and in the valving of the shocks. The 13.01:1 ratio, power-assisted rack-and-pinion steering of the Z51 package makes for quick response to driver control input. The suspension of the new Corvette is a totally integrated package which reflects many of the proven and efficient racing engineering practices. The use of forged aluminum suspension components reduced unsprung mass by nearly 30% which contributes to wheel control, ride and road holding. The payoff is that the new Corvette has demonstrated remarkable directional stability and transient response in surface testing on the GM proving grounds.
The Heart of the Corvette
Inspired from the race circuit, the new Corvette body design eliminated the traditional hood and introduced the front shroud. These changes lend to unobstructed access to the engine and front suspension, with each component developed in exactly the right place for function, serviceability, and fit. At the heart of it all. is the 5.7 Liter (350 CID) twin-throttle-body, Cross-Fire Injection V8. This was considered one of the world’s finest high-performance engines, and also one of the smartest.
Special Engineering Features
A lot of the excitement surrounding the 1983 Corvette release was related directly to the many design and engineering features apparent throughout the car. Chevrolet believes that a high-performance machine should as be a car that its owner can live with comfortably and rely upon. An automatic 4-speed transmission with overdrive was offered as standard equipment. An all-new 4-speed manual transmission with automatic over-drive on its top three gears, something that was exclusive to Corvettes, was available at no additional cost. Engineered with a hydraulically operated clutch at the front and a computer controlled overdrive at the rear. The basic feature of the hydraulic clutch is that it reduces shock-loading along the driveline during maximum acceleration from a standing start, and it also introduces damping similar to a shock absorber during quick shifts. The computer is designed to block out the overdrive during high-performance acceleration. The engineering of the new Vette goes far beyond transmissions that think, however. There is a cold air induction system supplying air to the engine by a twin-duct arrangement designed integrally with the clam-shell hood. Stainless steel headers lead to an exhaust that is engineered carefully to fit the new undercarriage configuration yet maintains the high-flow characteristics of the traditional Corvette dual exhaust.