Zymurgy

You are wrong. IMSA does set the maximum RPMs. It is part of BoP and is done individually by manufacturer, not for the class as a whole.

fatsport

Yep. Certainly isn’t needed to reach 7400 rpm.

Sounds bad *** on down shift though. I’m sure it would sound great at higher RPMs too.

I think a FPC would go great with the C8’s modern ME platform and DCT. Could this be development work and homologation for the C8Z? I hope so.

vndkshn

I think one thing not taken into consideration here is fuel use. They could very well be short shifting a little to conserve fuel (pretty common and very important in endurance racing) as well as protect the engine as a whole.

Reading this thread as well as the larger Daytona conversation thread, people seem to think the drivers and teams are (or should) be running at 100% lap after lap... that's not the way it works.

CorvettoBrando

Okay, sure bud. Lie to yourself all you want. Your post history tells otherwise. Always looking for a reason to be disappointed in the Corvette, whether it's a C7 variant, a C8 variant, or a C8R. You never asked the redline. You just stated that appears it's either being short shifted or it has a very low redline. Then you compared a high-revving, out of production, out of context video of a Ferrari FPC. Your OP had no question, nor did any of your subsequent posts, other than "that's it?" after someone offered the 7400 rpm redline based on imposed redline due to max power limitations in IMSA's BOP. To which you replied "That can't be right". It is right, within the confines of the IMSA competition. It is a higher redline than the Ferrari 488 GTE, within those IMSA confines. If either of those cars revved higher in IMSA comp, they'd exceed the maximum power allowed in the class. The Porsche 911 RSR cars, BTW, being NA 4.2 liter engines, need to rev to 9000 and above to reach max allowable power in the class.

So given the facts - which you weren't actually seeking to find, but were provided, what then, is your opinion of the Ferrari's FPC engine in IMSA form? Is it an inferior engine to the C8R's, since it doesn't "redline" as high?

As for the Corvette race car, no one other than members of IMSA, Corvette Racing Team and the engineers who developed the C8R, and top level GM members know the true redline and capabilities of the C8R's engine. Nor are they going to publicly announce them at this point, if ever.

Since you weren't actually fact-finding in your OP or subsequent posts, and were just spewing negative speak, why not just say what you're really thinking, which I infer to be "If a road-going C8 Corvette Z06 / ZR1 / Zora, or whatever its called, releases with a flat plane crank engine, and it doesn't rev to at least 8500 rpm, it will not be a high-revving car, IMO. A disappointment if so, IMO." And many here, whose experience with Corvettes is likely with cars redlining at or below 7000 rpm, will disagree with you, once we know the facts about the actual car. Some may agree with you as well.

Supermassive

From:

https://www.onallcylinders.com/2015/...e-crankshafts/

There is good reasons to go FPC over CPC, but it there are drawbacks too. I prefer the FPC rev capability...there is something to be said about how fast they can change crank velocity.

Ragtop 99

Is the converse true? A FPC requires a smaller crankcase? Would this allow a FPC engine to sit a little lower in the car than a CPC engine?

TFen

you must be new here.

quick04Z06

Yes, it is an IMSA BoP rev limit. Revs translate directly into horsepower and I feel confident the motor can rev higher if it were not artificially limited by BoP. I would suggest the rev limits may be changed during the season depending on adjustments to BoP. A rev limiter can be adjusted very quickly.

racerns

The main reason is that it is a 500hp car the weighs ~ 3200lb that has PDK. The C6Z06 could trap close to the same and was a regular manual. As a matter of fact C&D tested a 500hp manual GT3 and it ran 11.5@125 which is the same a C6Z06 was tested at. Yes lower gear ratios can make up for lower engine torque, but gearing can be adjusted to put the desired torque to the ground for what ever your engine rpm and torque rating is. There are always trade offs though. The main reason a the production C8 is not trapping 127mph is weight. Again, there is no reason to spin the C8R 5.5L engine at a higher rpm to achieve the hp limit they are given.

Rinaldo Catria

If GM plans to get over 650 hp in the Z06 from a NA engine its going to have to rev to the moon to get it. So its either higher revs than 7400 or it will need turbos IMO. If it is NA 5.5L it wont be the low end torquey monster we’ve become accustomed to IMO regardless of the “exotic aspect” of the flat plane DOHC.

erikgj

I think the crankcase would be about the same size.

tt 383

I fail to see how cranks with equal stroke would be too different. We are not talking partially counter weighted cast factory cranks but full center weighted forgings here. Should be minimal counterweight circumference swinging around.