higher rpm limit...

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cdstirland81
Posts: 183
Joined: Sat Jun 13, 2009 8:23 am
My Bike: ZXR400H1 and proud!
Location: derbyshire

higher rpm limit...

Post by cdstirland81 »

okay, curiosity has got the better of me here!

noticed a few of you are running either aftermarket ignition or modified cdi's letting you run 15,000rpm+,
and i have read in one post ( i think ), that one guy had cams that did not come into their zone until 14.000rpm+.

i was wondering, besides proper blueprinting and correct clearences, what other mods, like conrods, valvesprings,
etc is done to allow safe revving over the factory standard limit?

not looking to do this myself at this time, i am purely curious!

ta,

cliff
ameteurs practice and train unitl they can do it, professionals practice and train until they cannot fail at it..
ratbag56
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Joined: Wed Apr 18, 2007 7:18 pm
My Bike: zxr400 / 636
Location: gillingham, kent
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Re: higher rpm limit...

Post by ratbag56 »

the rev limit on ur bike is a safe setting if u see wot i mean! i think it can be reved to bout 15000+ rpm with out any mods if i am right but cant be held there that long for it goes bang! i have uped mine a bit only incase i need it but the power drops off after 14000 rpm
zimm
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Re: higher rpm limit...

Post by zimm »

I ran my H1 to 15,500, my peak power was around 14,700 i think and it held on to it almost into the limiter..

did half a dozen races like that (and a few hundred road miles) and didnt pop, but maybe i got lucky.. did find 2 slightly bent valves when it was stripped, but they could have been like that from the start (stock head, just skimmed + SP cams)

valve springs are the weak point from what i can tell, pay careful attention to the free length, and keep your valve clearances spot on... there may be SP spec springs .. i dont know.
rickyb
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Joined: Tue Dec 15, 2009 1:40 pm
My Bike: GSXR600K6

Re: higher rpm limit...

Post by rickyb »

I find you are OK to 15500 then at around 15700 the valve train starts to let you know if your springs are not in good shape, revved mine to 16000rpm for 2 seasons without any trouble and chip other peoples to 15400 regularly, but never revved one higher than 16K.
I believe Roger at RMKD has revved one even higher but you would have to ask him about that.

Rich
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