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tyre choice

Posted: Wed Jun 17, 2009 2:44 pm
by tomcat
need a new set of boots on the tomcat

probably will go for r888's again 205/40/17"

however I noticed these at a good price -anyone tried them -thought they might be better being a bit wider also


http://www.camskill.co.uk/products.php?plid=m12b0s684p0

Posted: Wed Jun 17, 2009 3:19 pm
by Stuart
RS2's are good, very good, but not on the same page as R888's from my experience. The other thing to consider is that width may not directly contribute towards grip levels and that's according to Alan from Toyo last night. It could be worth emailing or ringing him for advice Scott.

Posted: Wed Jun 17, 2009 3:38 pm
by Gerry H
I have Alan's info sheet for distribution but I'm waiting for confirmation from him that I can scan and post it up (copyright infringement).

Meanwhile I can email it to anyone who wants.

Posted: Wed Jun 17, 2009 4:09 pm
by Andy916
I like RS2's as well. Ran them on the road for a while and they were fine. Stable through a trackday session, doesn't seem to overheat. Can't compare to 888, would expect to be in different category as Stu says, but I know mikeb has had good experience with them too (and he normally sprints on '1B' tyres). Mr sidewaysfletch was also recommending Federal 595RS trackday tyres last night, another cracking deal from camskill.

Posted: Wed Jun 17, 2009 4:21 pm
by duncan
Wide is certainly working better for me. It helps to manage the heat better in my case and make the most of the 888's. Personally I would prefer it if the 888's had a harder sidewall like the A048R but they really give huge amounts of grip if you can get them set at the right pressures.

I would ignore the pressures that most seem to run these at personally I have found that much higher pressures seem to work much better and keep the tyre temps even over the tread and stop the shoulders tucking under. (this is with significant amounts of neg camber front and rear too)

Temp wise - they grip perfectly up to about 85C carcus temps then turn to jelly. They do go through a strange period on the way up to that where they feel like they are going off but they come back - maybe this is similar to what the F1 fraternity call graining but I dont know that for sure.

Posted: Wed Jun 17, 2009 8:04 pm
by tomcat
difficult to set the pressures as the range the recommend is massive like 28-42psi

I run mine at around 30psi -maybe a bit low?

I think I will try more front camber next time also as outside of tyre was as hot as inside.

shame with the toyos that there are such limited sizes I am stuck with 205's

Posted: Thu Jun 18, 2009 6:46 am
by duncan
Is that cold pressure?

Your target pressure should be after running (ie hot or as hot as they get).

How hot was the middle of the tread? If it is less than the edges then run more pressure. if it is more then run less. A tyre pyrometer is essential for that measurement. (probe type ideally)

Posted: Thu Jun 18, 2009 12:08 pm
by tomcat
duncan wrote:Is that cold pressure?

Your target pressure should be after running (ie hot or as hot as they get).

How hot was the middle of the tread? If it is less than the edges then run more pressure. if it is more then run less. A tyre pyrometer is essential for that measurement. (probe type ideally)
yes my middle was cooler that the edges by about 4-5deg

cold I set them at 26psi - then dropped them if they got more than 30-32psi

I did notice around the bomb hole I got a horrible chatter like through the steering -could be tyres rim flex?

cheers
Scott

Posted: Thu Jun 18, 2009 1:52 pm
by duncan
dont know about the chatter but from those temps you def need more pressure in them.