But don’t be fooled by the naturally aspirated flat-plane-crank V-8
We knew mid-engine ‘Vette fun was not strictly for the street. So did Chevy, which started work on both the street and race car simultaneously, in the same room, six years ago. But now we have the details of the Chevrolet Corvette C8.R, the brand’s first mid-engine Corvette race car, and a precursor to what we can expect in the Z06 –sorta.
Don’t let the engines fool you. The race car—Corvette’s first clean-sheet race car design since the C5.R in 1999 and obviously the first to move the position of the engine—has a 5.5-liter naturally aspirated flat-plane-crank dual-overhead-cam V-8 that generates 500 hp and 480 lb-ft of torque.
Moving to a flat-plane crank and dual-overhead-cam valvetrain design from a pushrod V-8 has the benefits of higher RPM and better breathing, potentially lengthening times between upshifts, and allowing lightning-quick downshifts from the sequential manual gearbox wherein the engine spins up to higher RPM much faster.
In other words, this is the exclusive race car variant of the flat-plane engine that is fully homologated to take other forms. MotorTrend has been told the Z06, when it comes, will have a twin-turbo flat-plane-crank dual-overhead-cam V-8. We expect it will be smaller displacement—the retail customer doesn’t want or need the extra vibration.
Both the C8.R and the Z06 also differ from the base Stingray which has the LT2 6.2-liter pushrod V-8, good for up to 495 hp and 470 lb-ft of torque (when equipped with the optional performance exhaust system), which Chevy says is the most powerful naturally aspirated engine in a mid-engine car. The engine was designed to be seen and is built from an aluminum block to drop weight and the Stingray’s center of gravity. It also gets a dry-sump oil system with three scavenge pumps, a first for a base-model Corvette, to deal with lateral acceleration levels that Chevrolet says can exceed 1 g in all directions.
The Stingray transmission is an eight-speed dual-clutch automatic but it shifts fast enough to make this the quickest Corvette ever, launching from 0 to 60 mph in less than 3.0 seconds, according to Chevy.
The C8.R race car uses a new compact Xtrac six-speed traditional sequential manual gearbox that is lighter and smaller, and was developed to make room at the back for a race-specific diffuser.
This is the closest link between track and showroom of any Corvette to date, said Mark Kent, director of Motorsports Competition. The C8.R shares more parts—about 100 really large ones, mostly structural— with its production counterpart than any previous-generation Corvette, which bodes well for the 2020 Corvette Stingray buyer with checkered flags in their eyes.
“It was important for us to develop the new race car alongside the production car, so that each product could properly take advantage of the new architecture,” said Ed Piatek, Corvette chief engineer. He promises that the balance and feeling of being connected to the road that the mid-engine supercar provides will be obvious on both the street and the track. Because the Stingray is essentially a convertible, it made it easier to develop the race car simultaneously, as much of the body stiffness comes from the tunnel in the center of the body.
There are some cool differences. For the race car, the frunk houses a radiator in the middle of the storage compartment, and the space where the radiator would normally go was instead used to package ultra-bright headlights to race at night. A rear hatch-mounted air intake is unique to the race car.
Aerodynamics are hugely important and engineers were testing 3-D-printed prototype parts in the wind tunnel early in the development. The race car uses the same production chassis as the Stingray but it is modified to meet race series requirements,and the final result is stiffer and lighter than the C7.R. The C8.R was designed to develop more downforce and has a large rear wing and rear diffuser. The car has aggressively flared bodywork and rides on 18-inch wheels running Michelin Pilot Sport GT competition tires.
The C8.R will compete in the next season of the IMSA WeatherTech SportsCar Championship, debuting in January at the Rolex 24 in Daytona. It will be the third decade of competition for Corvette Racing.
“We have looked forward to racing a production-based mid-engine Corvette for a long time,” said Jim Campbell, Chevrolet U.S. vice president of Performance and Motorsports. GM Engineering, Propulsion, Design, and the Corvette Racing team worked together to make it possible.
Chevy provided an advance look at the car before it is scheduled to do a hot lap at Road Atlanta on Saturday, October12, prior to the Motul Petit Le Mans that wraps up the current IMSA season. The silver No. 4 car for the demonstration is a nod to past concepts including the 1973 Chevrolet Aerovette and the 1959 Corvette Stingray Racer. The No. 3 car is traditional Corvette yellow with silver accents.
Front-engine Corvette racers have been staples of the sports car racing scene since the modern team’s inception in 1999, and have so far scored 107 wins, more than any other sports car team in North America, along with 13 Teams’ championships, and 12 Drivers’ and Manufacturers’ titles. In 2015, Corvette Racing became the first team in 15 years to claim endurance racing’s single-season “Triple Crown,” with wins in the Rolex 24, 12 Hours of Sebring, and 24 Hours of Le Mans.