Relive the historic 1990 Corvette ZR-1 endurance run where Morrison’s team averaged an astonishing 174.885 mph over 24 hours. Powered by the LT5, the C4 ZR-1 proved it could compete on the world stage, establishing Corvette as a true high-speed performance benchmark and cementing its place in modern Corvette history.
To start the Callaway portion of the video, Top Gear’s Jeremy Clarkson gets the back end out about 45-degrees on the first turn. After dissing the stock suspension and brakes inability to cope with the added horsepower from the Callaway twin-turbo engine, Jeremy tries to dial in the Corvette. He doesn’t provide any info about the Callaway, it appears to be an ‘87 model which probably didn’t yet have any suspension or wheel/tire improvements. What the car is very good at is bringing the back end around, which if you’re not used to, can be unnerving, to say the least.
Yesterday we told you about the ASTONISHING 254.76-MPH twin-turbocharged Callaway Corvette. The below video is an excellent presentation of this impressive machine. Reeves Callaway and project manager Tim Good take you on a full tour of the Sledgehammer project. You’ll get to see the Sledgehammer blast the Transportation Research Center in Ohio and even the late John Lingenfelter has a few words to say. Watch this and you WILL be a fan!
Even though the big news for the ‘92 Corvette was the LT1 350 engine with 300-horsepower (a 50-hp jump from the previous L98 engine), the 375-horsepower ZR-1 continued to get most of the attention. The ZL-1 and it’s LT5 engine had proven itself in March 1990 when the Morrison Motorsports ZR-1 shattered a 50-year 24 hour average speed record, recording an astonishing 175.885-mph speed!
The engine was so stout that engine builders, such as Corvette racing legend, Kim Baker, were building LT5 engines that were pulling horsepower figures in the low 600-plus range, WITHOUT the use of turbos, roots, or centrical superchargers! The LT5 was arguably one of the strongest engines to ever work under the hood of a Corvette.
For decades Chevrolet was rather shy about drawing attention to significant improvements to the t Corvette. Not in every case, but in many and 1992 was an excellent example. While the press was besides themselves with the exotic double overhead-cam LT1-powered ZR-1, hardly anyone noticed the arrival of the return of the LT1. The 350 L98 served the Corvette well from ‘85 to ‘91, enough to keep the Porsches and everyone else in the SCCA Showroom Stock series scratching their heads. Story has it that Porsche even bought a Corvette just to take apart to see why their 944s couldn’t keep up.
Take a test drive in a 1992 ZR-1 Corvette with Corvette engineer, John Heinricy and Indy 500 winner Rick Mears. This is an EXCELLENT. I wish these guys had done more of this. The engineering and race car driver perspective is first class. Enjoy. – Scott
