Consequence of raising the rev limiter?

Hi all,

I have the ability to raise the point at which the rev limiter kicks in on my racebike and am really tempted to bump it up 500-1000 rpm, to just allow me to hang onto a gear into some corners.

Obviously it'll put more strain onto the engine, but I won't be going past the existing limit on every corner - maybe just one corner a lap on certain tracks. If I can grab an extra gear, then I will - this is just extra in hand if I hit the limit just short of a braking point.

I'm just wondering if this is a good idea or whether I'll be asking for trouble. Bear in mind that this is a racebike, rather than a road bike.

Any thoughts?

[TSM]

are you talking about narrowing the range of the 2 stage soft limiter or raising the acutal final limileter?
you doing this with tuneboy

Originally Posted by TSM

are you talking about narrowing the range of the 2 stage soft limiter or raising the acutal final limileter?
you doing this with tuneboy

I don't know which limit Tuneboy adjusts - but yes, it is with Tuneboy

[TSM]

Originally Posted by lukemillar

I don't know which limit Tuneboy adjusts - but yes, it is with Tuneboy

tuneboy from what i remember has a 2 or 3 stage limiter, first one only half cuts the engine and the other is a full cut out until it drops rpm and also makes the bike feal softer as it hits the limiter

I cant say for sure Luke, id guess there would be some space to raise the rev's. An easier way might be to just gear it up a little... Yes you may not get as good acceleration but if holding a gear makes getting out of some corners faseter then it might work?

Best of luck with whatever you decide to do.


As to actual consequences:

With good oil regularly changed, a bike warmed up properly, and mapped so you're not trying to squeeze every last pony out of it; you'll be fine.

Bikes on the road have to be designed to cater for a lot of less-than-ideal conditions, and this is helped by keeping a fair bit of mechanical redundancy.

500 = No probs
1000 = Pushing it a little, so be careful.

[embee]

Rod stresses go with speed squared, so going from 10k to 11k increases stresses by over 20%, not inconsiderable and can easily exceed the design levels. Fatigue is cumulative and if you go beyond the fatigue limit regularly it might not be today, it might not be tomorrow, but it'll happen someday.

what rpm can you hit atm ?

i can hit 11k maybe 11.5k

mines one of the few k3's that has the high limiter

[jambo]

Originally Posted by gettin2dizzy

With good oil regularly changed, a bike warmed up properly, and mapped so you're not trying to squeeze every last pony out of it; you'll be fine.
500 = No probs
1000 = Pushing it a little, so be careful.

In all seriousness, the rev limit isn't about the effects of cumulative wear, where warm up and oil choice play a part, but total load. 500 - 1000rpm may not sound like a lot but it makes a big difference.

Originally Posted by embee

Rod stresses go with speed squared, so going from 10k to 11k increases stresses by over 20%, not inconsiderable and can easily exceed the design levels. Fatigue is cumulative and if you go beyond the fatigue limit regularly it might not be today, it might not be tomorrow, but it'll happen someday.

He's right you know.

Originally Posted by lukemillar

Any thoughts?

I probably wouldn't.

Originally Posted by barwel1992

what rpm can you hit atm ?

i can hit 11k maybe 11.5k

mines one of the few k3's that has the high limiter

I believe this is his 675, not an SV.

Jambo

^ lol im stupid didn't see his sig