Chevrolet released the technical details of the mid-engine Corvette C8.R during a special presentation at Road Atlanta today, confirming the race car will be powered by a DOHC 5.5-liter V8 engine with a flat plane crank.
The naturally aspirated V8 engine is rated at 500 horsepower and 480 pound-feet of torque, falling in line with IMSA’s regulations for the production-based GTLM class. Paired with the race-bred engine is a new six-speed sequential transmission supplied by Xtrac, which was specially developed to slot into the compact rear end of the mid-engine C8.R to make way for its massive rear diffuser.
Chevy describes the Corvette C8.R as its “first clean-sheet race car design since the C5.R debuted in 1999,” and is proud that it shares more components with its production counterpart than any of predecessors. The automaker says the mid-engine platform provides superior weight distribution over the Corvette C7.R’s front-engine architecture, as well as better aerodynamics. The race car’s chassis isn’t purpose-built by Pratt & Miller, either—it is a production chassis that starts its life in the Bowling Green Assembly Plant where the road-going Corvette C8 will be built.
“It was important for us to develop the new racecar alongside the production car, so that each product could properly take advantage of the new architecture,” said Corvette Chief Engineer Ed Piatek. “The benefits of this mid-engine supercar, including its incredible balance and connected-to-the-road feel, will be obvious on the street and the track.”
The automaker also shared a photo of the yellow Corvette C8.R livery for the first time. As we reported previously, Corvette Racing will run two different paint schemes on its No. 4 and No. 3 entries, with the No. 4 car using a new grey livery as a nod to previous Corvette concepts such as the 1973 Chevrolet Aerovette and the 1959 Corvette Stingray racer.
“We have looked forward to racing a production-based mid-engined Corvette for a long time,” added Chevy’s Vice President of Performance Vehicles and Motorsports, Jim Campbell. “The debut of the C8.R is the result of immense collaboration between GM Engineering, Propulsion, Design and the Corvette Racing team.
“As Corvette Racing enters its third decade of competition, we’re excited to begin the next chapter.”
Race fans in attendance at this weekend’s Motul Petit Le Mans IMSA season finale will have the opportunity to see the Corvette C8.R in action, with Corvette Racing set to turn some demo laps in the car prior to the start of the race on Saturday.
The Corvette C8.R will make its official competition debut at the 2020 Rolex 24 in January.
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Comments
There it is, my new bedroom wall poster! Twin C8.R’s
Love Jake’s new look!
Make that shop wall poster! ?
Guys,
Im confused. Whats the difference between a naturally aspirated 500 HP Stingray engine and a 500 HP Flat Plane Crank?
I don’t need a technical explanation but when the Z06 is released, what would the main difference be between these two?
Cheers,
Sean
“Im confused. Whats the difference between a naturally aspirated 500 HP Stingray engine and a 500 HP Flat Plane Crank?”
Without getting too technical, at present, it appears to be a difference in crank design and cylinder firing order. American V8’s generally use cross-plane cranks, of which the design leads to a lower-reving engines. By contrast, most other automakers use flat-plane cranks in their V8’s, which rev higher.
I wouldn’t say MOST other manufacturers use flat plane cranks. They’re quite uncommon.
Ferrari, McLaren, Porsche, Lotus……Ford. The flat plane crank revs much higher, but dosen’t have the balance of the cross plane. It is much lighter (hence the high revs) but develops much more vibration. Manufacturers have developed better dampening and control of these motors for more widespread use. I love the LT engines, but this is magnificent!
Expect this engine in the Z06 to make closer to, if not more than, 600hp. It’s restricted for racing
Note is has been common the race car to make up to 200 HP less than the street cars,
They often put air restrictions in the intake tubes to cut power. Turbo cars often get boost restrictions.
The street cars will be faster.
I had heard the the Z06 May be clots to ZR1 power and the new top car has been reported up to over 1000 hp with the electric front drive.
It will be interesting to watch.
Cross plane crankshafts have much heavier counter weights in order to balance it with the rotating assembly. Therefore a flat plane car can go through its gears quicker if there is enough traction to control wheel spin.
Also, the higher rev capabilities creates a wider power spread, they do limit the HP and not the usable RPM I do believe.
During development one of the powertrain engineers said the flat crank engine was coming. He stated they were only doing it for the sound as they were not making anymore power from the flat crank over the standard in the production engine. They wanted the more exotic sound.
They at that time had some vibration issues that they did resolve.
“He stated they were only doing it for the sound/-/ They wanted the more exotic sound.”
Sorry, I don’t believe that for even a millisecond.
“as they were not making anymore power from the flat crank over the standard in the production engine.”
The “production engine”? The one in the C8.R? it is capped at 500 HP, the rumors for the “production car are 600+ all motor, 800(ish) boosted.
“They at that time had some vibration issues that they did resolve.” Flat plane crankshaft in a non “flat” environment such as a “”V”” inherently have balance issues.
Believe what you like. I just state what the story said and have no skin in the game.
GM has had plans for smaller displacement hi-reving V8 for over a decade, it was to be the original “High Feature” engine and if I remember correctly it was to be a 9k-10k RPM engine.
The disadvantage from the manufacturers stand point is the almost double precision machining process to make them. With GM continued successful development of the pushrod architecture, and the mortgage (interest only) induced collapse of the economy. The funds to bring what was (then and now) to be a small in comparison to the LS/LT V8 production program to be shelved.
The benefits are there, moreso for every other manufacturer then GM. Due to the success of GM’s current V8 program. Chrysler/FCA has done well with the resurrection of the HEMI but the numbers produced pale in comparison and Ford did initially for the most part abandon the V8.
There was a time when all the forign makers balked at the idea of a V8, look at them know.
This 5.5 twin turbo race version will make closer to 700 to 750 HP. Remember that they use very high octane race fuel, not the 93 or 94 octane gas that is the rule for some race classes. With this special flat plane crank, it will rev at least 800 to 1000 RPM higher, meaning much higher HP at a higher RPM point. Here is the math for the flat plane crank. EG: With 600 pounds feet of torque at 6000 RPM, with a normal crankshaft, you get just 685 HP. With a flat plane crank revving at a higher 70000 RPM and a bit less 575 lbs feet of torque, you get 766 HP. I wonder if GM will offer this new crank through it’s Performance Parts dept. Great for drag racing where the life of the crank is not as critical as it is in longer races of 12 or 24 hours.
The truth is this engine should put out more HP than the present Z06 does now at over 600 hp on pump gas and no turbochargers.
The car will better get more power to the ground than the C7 so the next level up will be very capable.
I expect the Turbo to at least hit 800 hp.
The Vette team has never taken a temp back on their models in the recent years so it is only expected to see them add power to what we already have.
The one thing the Vette team has stated is they will never put in more than they can get to the ground. No HP for the sake of a big number HP that can not be fully used.
The closest non-turbo comparison would be the Ferrari 458 Italia which makes 562 hp @ 9000 rpm from its 4.5L V8. Of course the C8.R has a 5.5L V8 restricted to 500 hp but you should still get the picture.
The unrestricted street car should be even crazier.
Live to dream.. a new IROC series featuring the Chevrolet C8 Corvette.
The ford 5.2 flat plane makes near 535hp how come this is so weak. Should be putting out near 575hp based on what a 5.2 flat plane Ford makes. GM has better DI
This version is basically inhaling through a drinking straw. The 500hp figure is an IMSA limited configuration. They say 600+ in same tune with out restrictions. But let’s be honest this engine would probably not be breathing hard at 700hp N/A
Both engines are naturally aspirated. The difference is a floatplane crank engine fires every 90 degrees so you don’t need any counter weights which makes it lighter and smoother yes it does require rubber engine dampers. A cross plane crank fires every 180 degrees therefore you need counter weights thats why you get the bubble from the crossplane and the scream exotic sound from the flat plane. Naturally aspirated means no blowers or superchargers.