Dunlop SR3 slick questions

[silv]

Last time out at a Brands track day we seemed to pick up a lot of rubber so much so that I am considering using a heat gun and a scraper to clean them up. Tyre pressures all day were at 22psi ish all day. Is this normal? We never exprienced this with our clubsport when running Avons !! Thanks

[RobC]

Not wanting to sound rude but were you spending some time off line?

[Simon T]

Depends were you where parked in the paddock for a start. My RHS tyres tend to pick up quite a bit. You can clean them with a heat gun but your out lap will also clean them as effectively as the rubber is far spofter than the unused rubber on your tyre.

Dunlop currently recommend 21 psi as a cold pressure
http://www.radicalmotorsport.com/bulletins/2008_bu...

Simon

ww.tillingmotorsport.com

[silv]

RobC said:

Not wanting to sound rude but were you spending some time off line?

Hi Rob, maybe a bit more than on a normal track day as there were a lot of slower cars out there. I've got a feeling that not all the rubber is being picked up from the track! maybe we have got it wrong on the tyre pressure as the bulletin from Radical on Simon's post recommends higher pressures than we have been using.

Edited by silv on Wednesday 30th July 14:04

[splitpin]

I'm very confused by that Radical Chart: they are way higher than according to Radical's (so called) 'Owners Manual'; in there the pressures on my SR4 are stated as to be set to 14/16lb Cold, 20lb Hot; I followed these pressures at Silverstone last Tuesday and I picked up a lot of rubber / way more than I expected. It is true that I am running Michelin slicks rather than Dunlops, but surely that can't make that much difference to where the pressures should be set. Look forward to hearing what you think, in particular of course RobC who has almost certainly forgotten more than any of the rest of us will ever know. Deep respect.

[Simon T]

Rob has forgotten so much he even forgot about LH and RH threads yesterday

Tyre pressures have nothing to do with picking up rubber. This will happen more when your tyres are hotter so this may be why you are seeng more as the weather gets warmer. It really is nothing to worry about as it only happens as you slow down or go off line, normal runnig will clean off any pick up in half a lap

Simon

[splitpin]

Noted with thanks Simon: Any thoughts on that huge difference between those on the Radical Chart that you linked us to and those that appear in my Radical manual?

[Simon T]

Radical/Dunlop found that with the newer high downforce bodywork is putting too much strain on the side walls if the pressures were too low, this coupled with also large amounts of negative camber was causing the tyres wear on the inside on the tracks with longer straights and fail. There were also instances of a batch of incorrectly designed rims that allowed the tyres to roll off the bead if the pressure ws too low

S