The 1989 Corvette

The Overview

The 1989 Corvette is the ZR-1’s understudy, and most of what the ZR-1 needed arrived on it a year early. The Doug Nash 4+3 gave way to a six-speed manual designed with ZF in Friedrichshafen, with a 2.68:1 first gear, a 0.50:1 sixth and, to keep the car clear of the gas-guzzler tax, Computer Aided Gear Selection, a solenoid that locked out second and third at light throttle between 12 and 19 mph and forced a first-to-fourth shift; 4,113 buyers took it, and most of them learned which wire to clip. The Z52 package was retired because its contents became standard on every 1989: 17 x 9.5-inch twelve-slot wheels on P275/40ZR17 Goodyear Eagle ZR tires, Delco-Bilstein gas shocks, the 13.0:1 steering and the stiffened front structure, with the oil cooler, heavy-duty radiator and boost fan standard on six-speed cars. Z51 ($575) went on with stiffer springs, bushings and bars for 2,224 manual coupes, and on top of it came FX3 Selective Ride Control ($1,695, 1,573 cars): Delco-Bilstein dampers with electric motors on their rods turning rotary valves ten times a second, three settings on a console switch, Touring, Sport and Performance, each stiffening in six steps with speed. Only Z51 cars could have it, and only Z51 cars could have the leather sport seats.

The engine was the 1988 L98 with Multec injectors developed for the LT5, rated at 245 hp in coupes with the 3.07:1 axle (every six-speed car and automatics ordered with G92) and 240 hp in convertibles and 2.59-axle automatics; Road & Track’s Z51 six-speed ran 0–60 in 6.2 seconds and the quarter in 14.8 at 97 mph and pulled 0.91 g. The convertible gained a removable hardtop (RPO CC2, $1,995): fiberglass-reinforced polyester over a steel and aluminum frame with a cloth headliner and a heated rear window that plugged into a deck socket, taken by 1,573 buyers, and a simplified soft-top mechanism. The seats were restyled, the low-tire-pressure warning (UJ6, $325) came back cured and went into 6,976 cars, a block heater and a convertible luggage rack joined the list, and Callaway’s B2K, now $25,895, went into 69 cars.

The year’s real event never reached a showroom. Chevrolet unveiled the ZR-1 at the Geneva show in March 1989 and flew the world’s press to Carcassonne and Goodyear’s Mireval track to drive it; it was on every magazine cover by April, and on April 19 Chevrolet announced that “insufficient availability of engines caused by additional development” would push it to the 1990 model year. Eighty-four 1989 ZR-1s had already been built at Bowling Green for development, testing and the press, and they are counted in the year’s 26,412 cars; none was sold new, though a few have since surfaced at auction. The Corvette Challenge ran its second and last season on 60 new cars, thirty of them with swapped engines that Chevrolet restored afterward. Production rose for the first time since 1984, with 9,749 convertibles out of 26,412, at $31,545 for the coupe and $36,785 for the convertible. Today the 1989 is the first C4 most enthusiasts recommend to drivers: the six-speed, the 17-inch wheels and the FX3 option make it the best-handling L98 car for the money, and the 1990 interior is the only thing it lacks.

The 1989 Corvette Story

Since its introduction in 1984, the C4 had undeniably evolved into a sports car that could hold its own as a contender amongst some of the staunchest sports car competitors from around the world. With each passing model year, ongoing modifications to the engine, drive train, suspension and steering had transformed the C4 Corvette from a car that was recognized more for its handling than its performance into a machine which had successfully mated technology and horsepower.

The result of this fusion had created a platform upon which Corvette’s engineers and designers could (and would) breathe life into a car which was even more powerful than anything that had come before it. The fullness of that potential would manifest itself late in the 1989 model year and would transform the future of Corvette for all time – and would give rise to one of the most sought after Corvettes of all time – the ZR1.

As early as 1988, the rumblings and rumors of a new ZR-1 model Corvette had begun to circulate. With fuzzy spy photographs and a growing rumble amongst the Detroit automotive community, there had been a growing speculation that a new “King of the Hill” Corvette was on its way.

Chevrolet neither confirmed nor denied the rumors, at least until the 1989 Geneva Auto Show, when the ZR-1 was officially debuted. Boasting an incredible 375-horsepower LT5 engine (which had been developed by a team of engineers led by Lotus’s former Technical Director Tony Rudd), and a fully redesigned performance package, the car achieved an almost instant legend status amongst both Corvette enthusiasts and automotive critics alike.

After its unveiling in Geneva, General Motors invited a select group of automotive (and assorted other) media from around the world to the walled city of Carcassonne, France, where they were given the opportunity to test drive the ZR-1 Corvette. Additionally, General Motors used Goodyear’s test track at Mireval, France to show off the new supercar’s performance and improved handling abilities in a series of high-speed and wet-pavement tests.

Media reaction to the ZR-1 was initially fantastic. Within days of its unveiling in Geneva, the ZR-1 owned the cover of virtually every magazine in the world. It was featured prominently in publications such as Germany’s Auto Motor und Sport as well as England’s Car and AutoCar, to say nothing of the assorted American publications which hosted the new ZR-1 as their cover story.

However, despite the unprecedented and overwhelming media coverage further promoting the arrival of the “King of the Hill” ZR-1 Corvette, it was announced by Chevrolet on April 19, 1989 that the ZR-1 would not be available as a production model until the 1990 model year. While both the media and Corvette fans vehemently protested the announcement, GM gave the reasoning that there was “insufficient availability of engines caused by additional development.” Eighty-four 1989 ZR-1 Corvettes were built for evaluation, testing, media preview and photographing, but no 1989 model ZR-1’s were made available for public purchase.

Despite the disappointing news surrounding the delayed sales release of the ZR-1, 1989 Corvette owners would get their first glimpse of the future of the C4 Corvette, and a taste of things to come in following years. The first significant improvement to the Corvette in nearly half a decade involved the introduction of an entirely new manual transmission for the 1989 model year.

Designed in a joint effort between Chevrolet and Germany’s ZF (Zahnradfabrik Friedrichshafen), the new six speed transmission would prove to be a massive improvement over the never-popular Doug Nash 4+3 manual transmission which had been a part of the C4 Corvette program since its introduction in 1984.

The arrival of the new six speed transmission would be met with unquestioning approval, although its introduction would carry with it a certain amount of controversy as well.

In order to improve fuel economy as well as working to keep the Corvette from attaining a “gas guzzler” status, the new 6-speed transmission was built to include a new, Computer Aided Gear Selection (or “CAGS” for short) system. When operating the Corvette in low throttle conditions (anything under 35% throttle) or at speeds of between twelve and nineteen miles per hour, the CAGS system would lock out second and third gears, forcing the driver to shift directly from first to fourth. This feature, combined with a monumentally tall sixth gear for highway cruising, would keep the Corvette clear of the gas-guzzler tax.

While this feature of the six-speed transmission was deemed “annoying” by many early testers, GM assured consumers that the lock out option could easily be defeated simply by “clipping a single red wire” according to Chevy engineers.

Did you know? The SCCA’s Corvette Challenge would run for the last time in 1989. For the series, Chevrolet built sixty cars, thirty of which would have their stock engines swapped with higher-output engines from the CPC (Chevrolet-Pontiac-Canada group) engine plant in Flint, Michigan. At the end of the series, Chevrolet returned the original, numbers-matching engine to each of the Corvette race cars.

Another significant change for 1989 involved standardizing the Z52 package. While the Z52 option had been optional in previous years, it was now made standard on all models of the 1989 Corvette. For 1989, seventeen inch wheels and tires replaced the smaller, sixteen inch wheels which had been used on the C4 Corvette since 1984. Additionally, all models now included fast-ratio steering, Delco/Bilstein gas-charged shocks, and a fortified front end structure. For cars that were equipped with the new six-speed manual transmission, Chevrolet standardized the heavy-duty engine oil cooler, the heavy-duty radiator and the auxiliary radiator fan.

While the equipment previously associated with the optional Z52 became standard on all Corvettes, future Corvette owners were presented with an all new suspension option. RPO FX3 featured a selective ride and handling package. Priced at $1,695, and only available on Corvettes also equipped with the Z51 option, the FX3 system adjusted shock damping by adjusting suspension firmness levels specified by a console-mounted switch.

Developed by GM’s Delco division with Bilstein, the Selective Ride Control system used microprocessors to activate miniature electric motors at the top of each shock absorber. These, in turn, operated rotary valves that controlled the flow of fluid into the pistons. The system monitored and adjusted itself ten times per second and functioned during compression as well as during rebound.

Three suspension modes could be selected on the move – Touring, Sport and Performance – and each was designed to suit the mood of the driving condition. Within each setting, the damping rate increased with the car’s speed in six, twenty-five-mile-per-hour steps, from 25 miles per hour to 150 miles per hour.

Conversely, for periods during which damping was reduced, the set points were deliberately set five miles per hour slower to avoid the car constantly shifting between settings while cruising at one of the above speeds. When set to touring, the suspension would partially absorb ruts and pot-holes on back roads whereas Performance firmed the car up to something close to a race car.

By 1989, the Corvette’s interior, which had seemed futuristic in its appearance and styling when introduced in 1984, had become dated in its appearance.

While a complete transformation was still a year away, the interior did receive a fresh look with the introduction of restyled seats. Both the cloth, the standard leather and the more expensive sports leather material options remained available, though the leather sport seats were restricted to cars equipped with the Z51 option.

A stylized, removable, bolt-on hardtop was introduced for the 1989 model year as well. Made of fiberglass-reinforced polyester resin over rigid urethane, it was molded around a steel/aluminum “cage” and coated with polyurethane inside and out. A cloth headliner and window weather-stripping were included, as well as an electrically heated rear window (which plugged into a special rear-deck socket).

Priced at $1,995, the optional removable hardtop provided convertible owners the option (and function) of driving a convertible without the increased wind noise that sometimes accompanied a canvas soft-top. For consumers that preferred the factory soft-top, the convertible mechanism was simplified for easier operation.

For the first time in several years, the 1989 model year would actually see an increase in the total sales numbers of the Chevrolet Corvette. Even with the knowledge that the ZR-1 Corvette’s arrival was certain in 1990, Chevrolet sold a total of 26,412 Corvettes in 1989, of which nearly 10,000 units were convertibles.

The Callaway twin-turbo option, which now carried an additional cost of $25,895 over the Corvette’s base price, accounted for a mere 69 Corvette sales in 1989.

It seemed certain that the Corvette was about to take a huge leap forward with the arrival of the ZR-1, which relied on pure horsepower, and not turbochargers, to boost the performance numbers of the Corvette into realms never experienced before.

The Callaway option would continue through 1991, but with the ZR-1 coming its days were numbered, and the B2K cars have since become sought-after and highly collectible Corvettes in their own right.