Raising the Rev Limit

ThingKing

Child in Time
Joined
Aug 27, 2014
Messages
371
Location
Austria, Europe
Ride
2014 R3 Roadster, 2022 Hayabusa
Since I raised the rev limit on my 2014 R3R last year, I feel tempted to raise it further. I currently got TORs, Ramair and a custom tune in my PCIII.
It would be so easy to just go to the garage, connect the laptop and raise the limit from 6700 to, lets say, 7000 or even more. But is it a good idea? How far can I go without braking anything?
Thanks for any feedback, mates.
 
It's unlikely that your HP is going to go any higher above 6000 or 6500 without cams or high compression pistons. Just get it dynoed if you want to find out.
 
If you want more power - You'll need better breathing headers.

Go into the red band without adequate headwork - expect valve bounce and maybe collisions. BIG BILLS.

And you'll probably need something that lets in more air than the ram-air. Some form of velocity stack.
 
If you want to be able to rev more and get more power out, I'd suggest the Carpenter kits. Thanks to changes like replacing the valve springs they raise the limit to 9000, I believe. I'll join the people saying that raising the limit on a stock motor doesn't really make a lot of sense/difference.
 
If you want more power - You'll need better breathing headers.

Go into the red band without adequate headwork - expect valve bounce and maybe collisions. BIG BILLS.

Yes, I'm planning to go with CES headers.

So the valve springs are the first bottleneck?

I don't need 9000 rpm, something like a decent 7200 would do the job for me. At least for some time, but things like that tend to become an addiction...
 
Yes, I'm planning to go with CES headers.

So the valve springs are the first bottleneck?

I don't need 9000 rpm, something like a decent 7200 would do the job for me. At least for some time, but things like that tend to become an addiction...
Whatever you do, to make use of higher revs, you either need to move the torque curve up or to the right. The stock rev limit is probably conservative so raising it to 7000 probably won't damage the engine unless you wind the crap out of it every minute.
 
The stock springs/valve gear is fine to 7000 if you're not there for ages on end. The springs are on the weak side, they will rev more but will fail/float soon after 7 and it will shorten the life of the parts a lot. If your engine is stock you need to use the gearstick instead of 7000. There is not much torque up there anyway.
 
So the best way to go would be to have better valves and springs. Along with cams, I'd say, so there is actual rwhp output from the higher revs.
Anything else to bear in mind? Piston speed is not a concern at 7200, right? Thanks!
 
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