In early March 1990, the Chevrolet Corvette ZR-1 would set a new record for the highest 24 hour-5,000 mile land-speed by going over 175 mph (282 km/h). The engine specifications and story of this amazing car make captivating reading and you can see the car itself at the Australian National Show and Shine – Euroa, courtesy of Shepparton Corvette enthusiast Russell Pell.
General Motors became excited about the concept of developing the world’s fastest production car in the late 1980s and their C4 generation Corvette range was selected as the platform to achieve this.
After some early tweaking of the L98 5.7 litre engine failed to achieve the necessary result, GM turned to Lotus, following their acquisition of that UK based engineering consulting and performance car manufacturing firm in 1986.
The result was what GM dubbed the LT5, an aluminium-block 5.7 litre V-8 with the same bore centres as the L98, but with four overhead camshafts, 32 valves and two injectors per cylinder. Lotus also 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 bhp (280 kW) when at wide open throttle.
This “dual-mode” engine was controlled by a key, which meant that the driver had the capability of virtually turning off the car’s highest performance capability. This may have proved handy for drivers who were sceptical about the integrity of some valet parking attendants!
In addition to the engine, Lotus helped GM design the ZR-1's upgraded braking and steering systems and helped them pick the settings for the standard "FX3" adjustable active ride control that Chevrolet was fitting to the car, helping to ensure that the vehicle was more than just a modern-day muscle car with a big engine and no real capability on the track.
The ZR-1 is distinguishable from other Corvette coupes by its wider tail section, 11" wide rear wheels and its new convex rear fascia with four square shaped taillights and a centre high mounted stop lamp attached to the top of the hatch glass instead of between the taillights.
The car has a manual 6-speed gearbox, the first production car to offer this transmission. In 1990, you could buy one for just under $59,000 US.
The ZR-1 was produced by GM between 1990 and 1995. It is not surprising that the Corvette was used as a pace car at the Indianapolis 500 on many occasions.