Road cars and their endurance racing counterparts may look alike, sometimes sharing body panels, headlights, and even engine architecture, but in general, the stripped out, lightened race cars you see competing at Le Mans and elsewhere are nothing like the vehicles you can go out and buy. Chevy says its Corvette C8.R, however, shares more parts with its production equivalent than any other Corvette race car to date. Though that may be true, the list of changes from road car to race car is still extensive. Let’s go over some of the biggest differences between the regular Corvette and the C8.R that will race in the IMSA WeatherTech SportsCar Championship.
Let’s start with the engine. Motivating the road-legal Corvette is the now familiar 6.2-liter pushrod V-8 codenamed LT2—updated from LT1 in the C7—for 2020. The powerplant makes 495 hp and 470 lb-ft of torque when equipped with the optional performance exhaust. The C8.R on the other hand makes 500 horsepower (no word on torque) from its 5.5-liter DOHC V-8. These two engines are basically polar opposites. The V-8 in the race car has overhead cams and a shaft, which together allow it to rev higher and breathe better. One result of this is its much higher specific output. The LT2 retains the same basic overhead-valve design that GM small blocks have used for decades, and its cross-plane crank means it won’t rev as high as the race car. Though peak torque arrives at a relatively high 5,150 RPM, the LT2 will make most of its torque down low in the rev range. The engine in the race car is more than likely tuned for high-end power to help deliver maximum punch down the long straights of a track.
Both engines feature dry sump lubrication, direct injection, and are unaugmented by turbos, superchargers, or electric motors of any kind. The transmissions, however, are very different. The LT2 in the regular ‘Vette is mated to an eight-speed dual-clutch unit by Tremec, but the C8.R features an Xtrac six-speed sequential racing gearbox. Dual-clutch transmissions are quick, but the six-speed sequential in the race car is likely even faster.
Like the C7 and the C7.R, the two versions of the C8 Corvette share a wheelbase—107.2 inches. Unlike the last-gen car, the C8 and C8.R also share an overall length of 182.3 inches. They are different in every other dimension, however, especially weight. When MotorTrend weighed the C8 Stingray with the Z51 performance package it came in at 3,587 pounds, a gain of 151 pounds over the C7 Stingray. The C8.R is a featherweight by comparison. Chevy quotes a weight of just 2,733 pounds for their mid-engine racer. The race car is also 4.6 inches wider and 3.4 inches lower than the standard Corvette.