At a recent trackday I was encountering a a strange feeling during a heavy downshift from 3rd to 2nd gear. I was downshifting at around 12000 rpm and going into 2nd from 3rd for a tight 160 degree turn. Within a few seconds after the downshift the engine rev'd a little higher just like another downshift. It was not consistent with every lap only twice during the day. The F4i is an '03 with just over 6,000 miles, stock chain and sprockets, and standard tire sizes. I change oil before each trackday weekend with the HP4 synthetic blend 10W-40. Any ideas on what may be wrong if anything. TIA

Rob

 

So the RPMs went up with the downshift then a couple seconds later they went up again? If it was a higher gear I'd say clutch is slipping. Stiffer clutch springs are an easy and inexpensive way to find out. Only other thing I can think of is if you bounced it off the limiter.

 

That's exactly what it did it rev up after the downshift then it went up again. It did not hit the rev limiter, it was about a 1000 rpm from the rev limiter. That was what I thought the first time. Do you think that is the clutch spring limitations when trying to ring its neck or am I on borrowed time with the whole stock clutch? TIA

Rob

 

On my old turbo busa I was having clutch related slippage in every gear once the power came on -- even with new pads ($160 worth of fibers[:@]) Put on Heavy Duty springs (took like 15 minutes) and no more problems. On the busa it was scary as hell -- you'd get into the power then all of a sudden it would start revvin like crazy then BOOOOOM it'd catch and darn near fly out from under you.

 

I've only experienced it in downshifting so far. Is the acceleration slip something yet to come? Has anyone done the Barnett Clutch kit? http://www.indysuperbike.com/custome...t=26199&page=1

Is is worth the $120?

 

I have the Barnett kit, and I'm going to make it a winter project. Has anyone else replaced the steels and frictions themselves in the F4i? Any special tools required? Any advice would be appreciated.

 

i had the opposite happen my last trackday, i was actually getting false downshifts and revs would drop from 10K to 4K (so no engine braking helping me there) of course i pulled the shifter up a little and didnt have another problem.
clutch springs could very well be the problem.
as far as the price.... shop around and think if its worht your safety on the track.....