What is Powering the C8.R?
It didn't sound anything like any roadgoing or racing Corvette we'd ever heard before.
When the C8.R racing version of the 2020 Chevrolet Corvette was revealed Wednesday night, it pulled up with a bang. And a pop. And a brap. This thing was loud. Ear-splittingly loud. But it didn’t sound anything like any roadgoing or racing Corvette we’d ever heard before. So what’s going on out back under the C8.R’s engine cover?
We’ve heard straight-piped C7 Corvettes before, even the racing version with its 5.5L LT V8. But this sounded nothing like the low rumbly idle of those cars. instead, this C8.R we heard was far more frantic. Sharper. The kind of sound that cuts right through you. Chevrolet also showed a video of the C8.R rocketing down the runways of the John F. Kennedy Shuttle Landing Facility. Listen to the V8 and it’s a much higher-pitched noise than old racers and the standard new C8.
So what could be under that hood? And what does that mean for the road cars? Well, it could mean a lot for the road cars. Since the racers are designed for the IMSA GTLM class, based on the FIA’s LM GTE rules, and that class has some rules that are very specific for what’s allowed to power the racers. Though at the same time they’re also quite relaxed.
Yes, that does make sense. The strict part is that in order to be homologated for the car, the “engine must be derived from a series production engine produced at more than 300 units and fitted to a series vehicle from the same manufacturer.” So whatever Chevrolet Racing puts in here, it needs to come from something that goes in a road car. And with the cost of certifying engines for street use, that means it needs to go in a bunch of road cars.
So what does GM have that could fit the bill? There are already rumours of the 4.2L Blackwing V8 going into the Corvette, though it would be modified to be different from the Blackwing since that’s supposed to be a Caddy-only motor. Sure, it’s 4.2L now, but dropping it to the 4.0L class limit for turbo engines should be easy. And the current C7.R already drops the 6.2L engine to the 5.5L limit for racing use. Can you hear turbo noise in the clip? No, but then again you can’t hear it in competitors like the BMW Z4 GTE or the Aston Vantage GTE either.
It could also be version of the C8’s new V8, but fitted with a flat-plane crank. That, as you’d know if you’ve ever heard a Mustang GT350 at full song, can give an engine the ferocity the C8.R seems to have. Does that mean that the road car will get a flat-plane crank to meet homologation? No. It doesn’t. See, that’s the relaxed part. The derived part leaves it open to interpretation. Can you put a flat-plane crank in the regular street engine and be ok under the rules? Probably, as long as it’s not more than 10 percent lighter than the standard crank.
Could they make a flat-plane one for the C8.R? Yes. Could they use a turbo engine that’ll also be in the road car? Yes to that too. What are they going to do? We’ll have to wait and see.