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2009 Chevrolet Corvette ZR1
The ZR-1 returned with the 1990 Corvette lineup after an eighteen year hiatus.  This time, it featured a special LT5 engine that had been developed by Lotus (which, at the time, had been a subsidiary of General Motors.) The LT5 engine featured an all-aluminum block, four overhead camshafts, and 32 valves. It also featured an air management system which enabled the car to maintain proper operation while closing off half of its fuel injection system.
Offered from 1987 to 1991, the RPO-B2K upgrade was available from any Chevrolet dealer and also Callaway’s first major Corvette tuning program. Together, GM and Callaway made the upgrade package a Regular Production Order (RPO) which was the first time GM had outsourced such an option to a specialist manufacturer. It even had a factory back warranty. As the C4 updated, so did Callway’s program and by 1988, the B2K was pushing 382 bhp and 562 ft. lbs. of torque.
For the fourth generation Corvette, legendary Corvette racer John Greenwood developed the G4R. It was essentially a radical bodykit that usually followed a high level of performance upgrades. Included was a ground effects package that had integrated lights on the front valance. Furthermore the a new engine scoop and rear wing were fitted.