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View Full Version : Track day experience and throttle response



the_meek
09-15-2006, 02:53 PM
Hey,
I did a track day last week. Bike was superb, leaving KTM 660 and WR450s along the straight. Had some trouble i nthe corners:

1 Coming out of slower corners with fairly closed throttle, i found the throttle response hesitated a bit when getting back on the gas. It was enough to catch me out a couple of times as I wound it on a bit more when nothing happened and then it surged forward in a jump.

I've had it fully derestricted with the 15004 map on standard can and the throttle body sensor rescaled. Anyone noticed?

2 Found it hard to slide the back end in. Chattered a lot instead, even after winding the damping up. Any thoughts? Too slow? Too rough? Need to feather the clutch?
Couldn't slide it so i stuck my knee out instead. Yes this bike does it all!!

the_meek
09-15-2006, 02:56 PM
Sorry about the tyre photo. Look fine on my screen.

irie
09-15-2006, 04:59 PM
I got rid of the stock (crap) Dunlop tyres - fitted Pirelli SuperCorsa Pro SC1 front and SC2 rear.

Then I got the forks shortened and revalved and shock modified for tarmac use.

Bike now handles fine, but I have to get a GPR stabiliser 'cos the front can get a bit too loose because it's set to steer very fast.

Got a Sigma slipper clutch in it with a CRF450 clutch pack - works perfectly.

yellow.speedy
09-16-2006, 05:36 AM
my SXV tyre from street use :-)

waxxer
09-16-2006, 11:09 AM
I got rid of the stock (crap) Dunlop tyres - fitted Pirelli SuperCorsa Pro SC1 front and SC2 rear.

Then I got the forks shortened and revalved and shock modified for tarmac use.

Bike now handles fine, but I have to get a GPR stabiliser 'cos the front can get a bit too loose because it's set to steer very fast.

Got a Sigma slipper clutch in it with a CRF450 clutch pack - works perfectly.


Irie,

What size rear did you go with?? Did you stay with a 180?

Thanks in advance!:cheers:

the_meek
09-16-2006, 01:12 PM
any info on the throttle response or chattering?

irie
09-16-2006, 01:54 PM
Irie,

What size rear did you go with?? Did you stay with a 180?

Thanks in advance!:cheers:

Good question!

I raced the SXV at Brands Hatch (UK) in Thunderbikes because my SV700 engine wasn't completed in time.

I tried using a Pirelli SuperCorsa Pro SC2 160/17 tyre and ... the bike scared the living shit out of me! :eek:

So I put a 180 SC2 on and the bike was really nice. I truly expected the 160 to turn in really fast and be nicer than the 180, but I was wrong ...

irie
09-16-2006, 01:56 PM
any info on the throttle response or chattering?

Throttle response was faultless, but the stock forks chattered badly. They're OK for the road but shite on the track. They're now revalved etc. and work well.

Dr. Thrillride
09-16-2006, 09:47 PM
do the forks need shortening?


Throttle response was faultless, but the stock forks chattered badly. They're OK for the road but shite on the track. They're now revalved etc. and work well.

irie
09-17-2006, 11:23 AM
do the forks need shortening?

Yes, they've been shortened.

"H"
09-22-2006, 02:49 PM
ive just posted a thread asking how to solve my throttle response problem,its a nightmare on slow bends!

Scootopia
09-23-2006, 08:56 AM
We have found that the TB syncronization is crucial to smooth throttle response on these bikes. It seems to cause the bike to stumble from off idle and then abruptly come on all at once. Re-sync your TBs and reset the TPS and see if that helps. Make sure when you reset the TPS that there is enough slack in your throttle cable as not to have the butterflies open at all. We do this w/Axone not by sight. Back the idle screw out, then go into TPS mode and slack the throttle cable until the TPS reading bottoms out then do min position learn.

cyborg
10-09-2006, 11:48 PM
I got rid of the stock (crap) Dunlop tyres - fitted Pirelli SuperCorsa Pro SC1 front and SC2 rear.

Then I got the forks shortened and revalved and shock modified for tarmac use.

Bike now handles fine, but I have to get a GPR stabiliser 'cos the front can get a bit too loose because it's set to steer very fast.

Got a Sigma slipper clutch in it with a CRF450 clutch pack - works perfectly.

Irie, how were the forks shortened? Also where did you get the Sigma slipper clutch? Did they make it for the Aprilia specifically or Honda?

Might seem nuts, but I'm thinking about lowering the RXV just a bit. Shorten forks a bit, change the rear dogbones...

irie
10-10-2006, 04:54 AM
Irie, how were the forks shortened? Also where did you get the Sigma slipper clutch? Did they make it for the Aprilia specifically or Honda?

Might seem nuts, but I'm thinking about lowering the RXV just a bit. Shorten forks a bit, change the rear dogbones...

I'm based in the UK

Forks were shortened by HM Racing www.hmracing.co.uk

Sigma slipper clutch came from Sigma www.sigmaperformance.com

It's the CRF450 unit. I bought a complete CRF450 clutch pack and it all went in no probs and with no adjustment. I bought a clutch pack because my steel plates would fit neither an STM nor Sigma slipper clutch (I suspect that early bikes may have had alternative sourcing of clutch plates) and the clutch pack cost pretty much the same as Honda OEM steel plates by themselves.

cyborg
10-10-2006, 08:36 AM
I'm based in the UK

Forks were shortened by HM Racing www.hmracing.co.uk

Sigma slipper clutch came from Sigma www.sigmaperformance.com

It's the CRF450 unit. I bought a complete CRF450 clutch pack and it all went in no probs and with no adjustment. I bought a clutch pack because my steel plates would fit neither an STM nor Sigma slipper clutch (I suspect that early bikes may have had alternative sourcing of clutch plates) and the clutch pack cost pretty much the same as Honda OEM steel plates by themselves.

Good info. Can't use the HM Racing, wonder if Sigma does business in the States. The shipping often kills the deal. It will be interesting to see how many parts from Honda/Yama/Suzi/Kawa end up fitting the RXV/SXV.

amauri
10-10-2006, 09:19 AM
I've had it fully derestricted with the 15004 map on standard can and the throttle body sensor rescaled.
Why are you running 15004 with the std exhaust?

Load 15002 and get the throttle bodies synchronized.

yellow.speedy
10-10-2006, 12:12 PM
longer injection helps!!

irie
10-10-2006, 02:18 PM
^^^ what does that mean?

dizzy
10-10-2006, 06:17 PM
Increase injector duration, although there's a little more to it than more is better. You shouldn't run the race maps with a standard exhaust either. 15001 and 15002 are suitable for use with the OE exhaust system.