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Bigger rear tyre size to change max speed.
Custardpants - 7/5/12 at 12:08 PM

Hi Guys - setup/handling question for an MK Indy R. I'm finding that running 195/50/15 is good for shorter straighted circuits like cadwell - but if i change my rears to 205/60/15 my top speed will go from 118 to 130, which will be perfect for longer circuits like bedford. What other effects will this have other than adding 10-12mm of rake?


liam.mccaffrey - 7/5/12 at 12:20 PM

reduced acceleration


Macbeast - 7/5/12 at 03:34 PM

Speedo ( if any ) will read low.


Canada EH! - 7/5/12 at 04:43 PM

will the Busa pull that kind of speed?


Custardpants - 9/5/12 at 03:40 PM

Thanks for the replies. I know this locost shape has a reputation for being crap above 80mph but my car will easily approach the limiter at 118 in sixth gear on partial throttle - I doubt 130 will overly bother it in areas such as the bedford straight and the quicker bits of donington, but only one way to find out.
Have a speedo healer anyway so thats easy to sort. More bothered about handling effects of the additional rake - maybe it will make it even more stable?


steveiow - 9/5/12 at 05:18 PM

If you are raising the ride height of the rear of the car would you not find it ends up very tail happy?

Also, I would question what effect an increased sidewall height would also have on handling.

I have no idea about bike engines, but if I had the power and wanted to go faster I would simply fit a different diff. Is this something that is irrelevant in your case?