UnhandledException

Listening various C8R clips, I am quite confused about this flat plane crank engine. It appears like it is being either short shifted or it has a very low redline. I have been watching C8R very closely and when I watched the initial videos of it being showcased, I said the driver is probably not pushing the car. But then I watched the 24 hour daytona clip and it is the same.

to compare please go to youtube and watch any ferrari flat plane crank such as below:

C8Jake

why

UnhandledException

to compare what flat plane crank sounds like or what “high revving” means for a V8. Because a large portion of this forum and corvette crowd does not have a lot of experience with that type of engine, people may not know what is expected. Its not ferrari vs corvette. Its about baseline.

If you have nothing constructive to say, dont say anything just to derail the topic.

BahamaTodd

At least compare apples to apples. The Ferrari 458 GT2 car also doesn't sound like it revs very much, but the 4.5L V8 (non-turbo) production car revs to 9000 rpm.

C8.R

Ferrari 458 GT2 - (6250 RPM redline)

Ferrari 458 Production Car:

z28lt1

It's 7400 RPM.

Supermassive

There is also the whole thing regarding the power limit for the car and longevity/reliability. The chance of a car with 9000 rpm redline breaking during a 24 hour race is higher than one that revs at 7500 and so on. There are cars that rev higher in endurance racing for sure, but the name of the game is endurance. Limiting power to 500hp also allows the race engine to be tuned to make that power at a lower rpm.

For us the buyers of sports cars, high rpms are part of an experience but not really necessary for actual performance. The 911 GT3 winds out its motor because they are pushing the limits of the 4.0 flat six without turbos. Ferrari and Lamborghini and all the other high revving engine makers are trying to capture a bit of the exotic and racing feeling of F1.

While I hope for more than a 6500 rpm redline on the Z06, it wouldn't devastate me if they didn't.

BahamaTodd

Good point. The Ferrari GT2 video I posted only had a 6250 RPM redline.

BJ67

Looking at the BOP adjustments released for the 24 hrs at Daytona race it shows max redline for the C8 R at 7400 rpm along with all the specs of all 6 cars in the GTLM class. I do agree listening to these cars on track it sounds like they are not reving very high. Maybe its the flatplane crank and firing order changing the sound so it doesnt sound like its winding up. I would love to see a in cockpit video clip during a couple of laps and concentrating on a tach to see where these cars are being shifted at during WOT acceleration from lower speeds. RPM capability is one of the pluses of the flatplane crank and DOHC engine design.... so whats up chevy??? Maybe 5.5 liter is too large to twist? Ferrari have alays been under 5 liter and ford is 5.2.

UnhandledException

Thats it? That cant be true. Even the turbo charged BMWs redline at 7600 rpm. Or the supercharged GT500.

I dont consider anything below 8500 “high revving”.

BahamaTodd

The C8.R racecar is limited to 7400 RPM. Also a major reason why the Z06 is going to make more power than the C8.R since it will not be restricted.

C8Jake

racerns

You do realize that because of the class requirements that they are pretty much limited to ~500hp? For a 5.5L engine there is no reason to spin it above 7400 rpm to get the required hp. That doesn't mean the engine is not capable of spinning higher.

fatsport

There’s definitely a reason to spin it higher. Higher rpms allow lower gear ratios while accelerating, effectively creating more power to the ground. How does a GT3 with 500 hp and only 338 ft/lb of torque run 127 mph in the quarter mile? Lower gears with a 9K redline.

Pretty sure it’s a limit set by IMSA to balance competition and improve durability. Maybe someone with more knowledge about the rules can clarify.

ChumpVette

Another Johnny Come Lately. Go back and watch C5/6/7 clips and see how they Rev.

vettesweetnos

Anthony Chan

Damn 9400 RPM for the Porsche.

UnhandledException

I dont think IMSA limits per RPM as porsche revs 9400 rpm.

CorvettoBrando

You are correct on the above. The C8R's engine performance, including redline, was/is entirely governed by IMSA's BOP metrics for the race. The BMW and the Ferrari, both turbocharged DOHC engines (one flat plane and one cross plane), were controlled at 7000 rpm. So for the race and the testing, the C8R actually was revving higher than the Ferrari competitor. The Porsche, the other NA engine in GTLM, is permitted to rev to 9400 to reach maximum allowable power (in the class).

What a ridiculous OP. Not surprising given his/her/its post history. UHE, If you were actually "watching the C8R very closely", you would know about the IMSA BOP - imposed redline, which cannot in any way be confirmed as relating to any aspects of the future performance variant(s) of the road car. We don't even know that the future road car will feature a flat plane crank engine. Do your research before trying to spin a negative post about a race car, based on your highly UNTRAINED ear, and implying that it might be a potential downside to the new version of the C8 Corvette street car - version whose configuration (including the engine) is not yet even known or officially announced as upcoming. The "Uh oh / Oh no" tone of nearly all of your posts are not lost on us. Find a new hobby. We see right through you.

UnhandledException

All you did was to prove my ear is TRAINED. Because all I did was to question how high the engine revved. I asked the redline in C8R. And the answer, 7400rpm, supported my belief that it does not rev high.

i did not bash the car nor criticized it. You took everything I said in the wrong. It was merely a fact finding question.

Racer X

So far I am seeing nothing that suggests a flat plane crank is needed. Seems like an unnecessary complication for no benefit so far.