Premature Engine Failure - Boxster

[Brucelee]

Jim.

I think Lotus engineered the ZR-1 (LT-5) motor for Corvette, not the LT-1. That was the engine that was produced for GM by Mercury Marine and had 32 valves etc.

If this is correct, then Lotus SHOULD brag about that engine, as it was a terror. I had a red 1990 zr-1 and it was freaky fast for its day.

See below.

During 1986, General Motors acquired Group Lotus, the UK based engineering consulting and performance car manufacturing firm. The Corvette division approached Lotus with the idea of developing the world's fastest production car, to be based on the C4 generation Corvette. With input from GM, Lotus designed a new engine to fit in place of the L98 V8 that was powering the standard C4. The result was what GM dubbed the LT5, an aluminum-block V-8 with the same bore centers as the L98, but with four overhead camshafts, 32 valves. 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 a stellar 375 hp when at wide open throttle.

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 "ZX3" active suspension system 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.

GM found that the engine required special assembly, and that neither the Corvette plant in Bowling Green Kentucky nor any of their normal production facilities could handle the workload, so Mercury Marine corporation of Oklahoma was contracted to assemble the engines and ship them to the Corvette factory in Bowling Green where the ZR-1s were being assembled.

The vehicle went on sale in 1990 and was available only as a coupe. It was 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 CHMSL (center high mounted stop lamp) attached to the top of the hatch glass instead of between the taillights.

The ZR-1 displayed stunning ability both in terms of acceleration and handling capabilities, but carried with it an astonishingly high price. MSRP for the ZR-1 in 1990 was $58,995, almost twice the cost of a non-ZR-1, and had ballooned to $66,278 by 1995; it has been rumored that some dealers successfully marked units as high as $100,000. Even at base MSRP, this meant that the ZR-1 was competing in the same price bracket as cars like Porsche's 964, making it a hard sell for GM dealers.