Chevrolet Corvette (C4)
Corvette C4 Coupe ( 1983-1990 )
The Corvette C4 was built by the spring of 1983 until the end of 1996 as the fourth generation of the Corvette. A convertible in the C4 was introduced in early 1986.
This model with an even slimmer body than its predecessor Corvette C3 and extremely flat to 64 degrees inclined windscreen and an entirely new suspension set in terms of handling and performance sets new standards in the sports car segment. No other production vehicle then reached for example a higher lateral acceleration when cornering.
- 6.6.1 Sledgehammer
History
In the spring of 1983, was introduced after fifteen years of production of C3 to the C4 a revised model. However, the new Corvette came with the Model 1984 to the dealers. The comparatively late start of production in March 1983 led to Chevrolet General Manager Robert stamp decided to leave to start a new generation with the same model year 1984.
In order to improve the handling and the weight distribution again C4 developer engaged the motor in the direction to the center of the vehicle bulkhead. The wider transmission tunnel gives the body more rigidity. ABS (from 1986) and Traction Control ( since 1992) increased active safety. A new six-speed manual gearbox from ZF (1989 ) decreases the fuel consumption. According to the previous generation engine capacity and horsepower records only V8 engines came in the C4 with a 5.7 liter engine used. From 1985, the new L98 engine with modern fuel injection from Bosch, including air mass measurement was installed. Despite the increase in output from 205 to 230 hp, fuel consumption drops by 11 percent.
The lines was rather reserved and the motors only moderately strong according to previous Corvette - scales. Against strong Ferrari or Porsche could again until the Corvette ZR -1 score, which came on the market in early 1990. Another record in the history of high-performance sports car was set in 1992 with a white convertible ( cabriolet ): The one - millionth Corvette rolled off the assembly line, matching the opening of the " American Corvette Hall of Fame" in Cooperstown, New York.
The Corvette C4 was built in March 1983 to the end of 1996 to a total of 358 180, including 74 651 convertibles. In early 1997, appeared after 13 years of construction, the successor Corvette C5.
Body and interior
The first time was dispensed a conventional recessed hood. Instead there was a so-called clamshell hood, the fenders, along with the extended to the lateral circumferential moldings and thus was open as entire front. Thus was released by opening the hood almost the entire engine compartment.
The fourth edition of the sports car received from the designer Jerry Palmer a clear functional lines in the style of the 80s. This no-frills proven particularly in the wind tunnel: The drag coefficient of 0.34 is among the best aerodynamic results of that epoch, a merit even at 64 degrees very shallow standing windscreen. The dome-shaped rear window is the largest glass surface that had possessed up to that time an American car.
Overall, the Corvette C4 came slightly smaller than the curvaceous predecessor C3: Compared with the previous version of C3 - C4 1982 shrank in length by 16 cm to 4.48 meters, but grew in width by 5 cm to 1.80 meters. With a height of only 1.19 meters, but she ducks so deeply on the street as none of their ancestors.
After exactly ten year break, a cabriolet was available again from the beginning of 1986. The roof was held under a flat flap place. Although the open Corvette cost more for the first time as the coupe ( approximately U.S. $ 5,000 ), for example, decided in 1987, one in three buyers for the Cabriolet. The C4 was like the C3 also a removable Targa roof. Now it was but for a whole piece, rather than as the previous two halves of the roof (T -Top). In the previous remaining after removal of the two halves of the roof in the middle of a ridge roof. In the C4 this central web accounted for the first time
Entirely new were the pointer -less instruments in the interior. In the cockpit was dispensed with analog displays, LCD displays have been used instead. The entire cockpit was designed rather futuristic and innovative, which, however, was not to everyone's taste.
Chassis / Suspension
Suspension and chassis of the C3 were replaced, the Corvette C4 now got a modern system with independent suspension and five-link rear axle. The transverse leaf spring front, albeit made of lightweight plastic, was rather unusual. The suspension consisted of light alloy.
The developers of the Corvette sat in the C4 to consistent lightweight. Suspension components such as the upper and lower front transverse control arm, the bracket of the generator and part of the power steering and the air conditioning compressor is produced in the C4 models of aluminum, as the drive shaft is made of forged light alloy. The hood is a sandwich composite part. The radiator has aluminum fins and a surge tank made of plastic, plastic is from 1985 for the housing of the brake booster also used. In the cylinder heads comes from 1986 aluminum for use.
For the development of the new generation tire was working with Goodyear. The original idea to provide the tire with a " Corvette " lettering, but was rejected shortly before the start of production. As part of this collaboration, the " Gatorback " tires, which allowed a lateral acceleration of 1.01 g in conjunction with the designed for high speeds suspension formed ( with special " Z51 " suspension setup, roadworthy only 0.90 g ), which was previously achieved with any production car.
Among these measures, however, suffered the driving comfort. The MJ '84er Corvette obviously had to convince great effort, testers and critics of the qualities of their nearly race-ready suspension. The ride comfort was only slight, regardless of whether the car but made it very easy to control with the normal suspension or the option " Z51 ", which brought a further hardening suspension.
As early as 1985 received the C4 again a revised chassis, with which the problems have been fixed. The spring rate of the production Corvette has now been reduced to half of the previous version. The same was true for the option " Z51 ". From 1988 could with the options " Z51 " and " Z52 " in addition 17-inch wheels are ordered, which measure the C4 with the European competition and was due to greater price-performance ratio prevail in many cases.
Motor
Also as of 1985, taken from the C3 L83 engine with Crossfire injection system with the new L98 engine with TPI ( Tuned Port Injection) was replaced intake manifold injection. The new engine had more power and lower consumption. The performance was last at 180 kW ( 245 hp ) at 4,000 rpm and a maximum torque of 448 Nm at 3.200/min.
1992 replaced the turn new LT1 engine the outmoded over the years L98. With constant consumption of slightly more compact be built LT1 brought about 20 % more power, maximum torque was indeed about the same as the L98, but was at 800 rpm until later. Thus, the performance of this engine now (306 hp ) stood at 225 kW at 5.200/min with a maximum torque of 451 Nm at 4,000 rpm. Only this LT1 engine helped the normal Corvette C4 compared to other sports car respectable performance.
1996, the last year of the C4, was raised with the LT4 engine power and rated speed again. The LT4 has a higher compression ratio than the LT1 and provides 243 kW (330 hp) at 5.800/min. However, the LT4 LT1 has not completely replaced, because the LT1 was still used on all specimens with automatic transmission, while the stronger and higher rotating LT4 occurred in all manual transmission Corvettes, including the special edition Grand Sport for use.
Facelift
In 1990, the interior of the C4 has been thoroughly renovated. There was a new driver-oriented cockpit. Speed , voltage, temperature and oil pressure were again displayed with analogue instruments rather than with LCD displays. Speed , fuel level and the trip computer functions were still displayed digitally.
For the 1991 model was followed in the summer of 1990 an external facelift for the front and rear have been changed significantly. The car's nose was rounded and the lamp units seemed drawn around the corners. The new tail was optically aligned on the published in 1989 ZR -1. The tail lights were no longer around, but strongly rounded rectangles.
Variants
35th Anniversary
1988 was put on the market for the 35th anniversary of the Corvette of the C4 a " 35th Anniversary " special model. This model could be obtained only as a coupe with full equipment and in the color white, also with white painted aluminum wheels. The normally body-colored roll bar was painted black. The most striking feature was the fully upholstered with white leather seats and the white two-spoke steering wheel. From this model, a total of 2050 units were built, each with a numbered plaque. 180 of these vehicles were equipped with a manual transmission.
Indianapolis 500 Pace Car Replica
1995 500 race for the third time has been used since 1911 as a Corvette Pace Car at the prestigious Indianapolis. Chevrolet brought in the same year a replica of this pace car as a special model on the market. It was fully equipped convertible with automatic transmission, a two -tone paint in white and purple and a white top. Each copy was a flashy sticker set, which stretched around the front and on the complete vehicle flanks. The interior was black with two-tone seats in black and purple. In the headrests, the logo of the 79th Indianapolis 500 was embroidered. It 527 Indianapolis 500 Pace Car Replica was produced.
Collector Edition
As in 1982, to bid farewell to the Corvette C3, there was also the last year of the C4 a non- limited special model named Collector Edition. Perhaps the most striking feature was the paint in silver metallic as this color it was the first time since 1988, again on a Corvette and exclusively for the Collector Edition. Furthermore, the Collector Edition models special emblems on the front, rear and wheel hub covers, silver-painted 17-inch 5-spoke alloy wheels, black -painted brake calipers with Corvette lettering and gray sport seats with embroidered Collector Edition lettering had. There 5,412 copies were built, of which 1,381 convertibles.
Grand Sport
1996 another Corvette legend was revived: the Z16 option was called Grand Sport and was delivered only in Admiral Blue with a central white stripe over the vehicle and other smaller specialty details. As an engine of the LT-4 was used, the (330 PS ) carried out 243 kW and was delivered with 6-speed manual transmission. The leather interior of the Grand Sport Corvette could be ordered in black or a combination in red and black. The Grand Sport Corvette was given its own VIN number series ( Vehicle Identification Number) and the number of units of this vehicle series was limited to 1000 units, of which 810 coupes were produced and 190 convertibles ( convertibles).
C4 ZR -1
In 1989, GM to the public its own high-performance variant of the fourth - generation Corvette before, which was sold from 1990 ZR -1. The ZR -1, described in the press quickly as "King of the Hill", was the former top model of the Corvette and should compete with their completely redesigned DOHC V8 aluminum engine against European sports car competition. ZR -1 is identified by a 11 cm wider rear relative to the normal C4. The broadening is for very wide tires on 17 -inch wheels (315 /35 ZR 17 ) is required. For the first time in a Corvette, the "Selective Drive Control" chassis was fitted with from inside the adjustable damping.
Motor
In 1990, appeared in the C4 Corvette ZR -1, the new LT5 engine. For the propulsion of the ZR -1 was provided by a new development, which was jointly developed by Lotus and Chevrolet. The LT5 engine based on a design by Lotus was (at that time the GM- group belonging ). On the basis of this design of the LT5 was developed at Chevrolet and adapted primarily by increasing the displacement to the Corvette. The LT5 engine was produced in the USA by Mercury Marine in Stillwater. This machine with 32 valves was reserved exclusively for the ZR -1. The performance was initially 280 kW ( 385 hp ) at 6000 rpm, maximum torque 502 Nm at 4800 rpm was. With the strong LT5 engine, the ZR -1 reached a new peak power for Corvette models. From model year 1993, the power was increased to 302 now kW ( 411 hp ) at 5800 rpm and 522 Nm at 4800 rpm.
Performance
The performance figures were for that time well within the super sports car. The acceleration from 0 to 100 km / h was specified from the factory with 4.4 seconds. The factory specification for the maximum speed was 290 km / h The vehicle reached in tests top speeds of over 300 km / h and was 1990 several world speed records recorded: for example, the FIA -24- hour record with an average speed of 283 km / h over a total distance of 6793 kilometers. Until the appearance of the Corvette C5 Z06 ZR- 1 was the fastest and most powerful Corvette ever built.
In the last year of production of the C4 in 1996, the ZR- 1 was no longer offered. It was produced until 1995 and a total of 6939 pieces produced. The model was replaced with the limited " Grand Sport " version.
Callaway
1987 was offered a new option called " B2K ". Reeves Callaway built two turbochargers in the Corvette, which helped her to a top speed of over 300 km / hr. The previously published B2K models had a power output of 257 kW (350 hp) and 610 Nm. Later versions contributed 336 kW ( 457 hp) and 831 Nm. The B2K option could be ordered until 1991, but was initially only available in the USA. Later Callaway offered the Corvette C4 B2K also on the German market. This then made 409 hp at 4500 rpm and had a torque of 780 Nm at 3000 rpm.
Callaway tunes not just the Corvette engines, but is based on a special version of the small-block V8, the crankshaft bearings are bolted with four bolts instead of two. There were also in the B2K version a forged crankshaft and Cosworth pistons and two IHI turbochargers with intercoolers, which put the machine under 0.8 bar pressure. The twin-turbo Corvette did not need high speeds in order to develop their strength. Thanks to a differential lock the car brought the power well on the road.
Sledgehammer
By the term " Sledgehammer " ( forging hammer / sledgehammer ) Callaway built in 1988 also a 880 - hp version of the Corvette, the October 19, 1989 - driven by John Lingenfelter - a top speed of 254.76 mph (about 410 km / h ) reached. The test was conducted in Columbus, Ohio, on the route of the Technical Research Center ( TRC) with a modified '88 Callaway Sledgehammer (No. 51).
The whole car was designed for speed and directional stability, but still provides comfort. Among the many changes to the engine and vehicle compared to a standard Corvette are two turbochargers Turbonetics T04B that provide 1.5 bar of boost pressure. The transmission of the Sledge hammer is a Doug Nash design for NASCAR cars. The tires were made by Goodyear specifically for this car and are mounted on Dynamag rims.
However, these Callaway Sledgehammer version was never an official GM option. Officially it was announced that it was in sledge hammer to a test vehicle for the tire industry, with the opportunities of a normal road tires should be tested.
By the year 2007, the Sledgehammer Corvette the fastest land vehicle street legal was with 409.9 km / h top speed world. Not even published in 2005 Bugatti Veyron was faster. This record was, however, on 17 September 2007 broken by the SCC Ultimate Aero TT with 412 km / h. The Sledgehammer was approved in the U.S. only.