15 replies to this topic

[JimmyJamJerusalem]

I'm running 245 rears and 215 fronts. Was wondering if people had decent sticky track pressures for these tyres. We ran them last year at Le Mans and they were ace but cannot remeber the setting. Don't have the luxuary of trial and error as I'm running Nitrogen filled tyres and wont be able to refill once I've pushed it too low. I'm guessing 26-28psi hot will be the best setting.....

[chris_uk]

isnt there some data online to show what best working temps the tyres run at?

[chris_uk]

These pressures are for tyres inflated with normal “Wet” compressed air.
Vehicle Weight<1100kg

Minimum Cold
Front 24 psi
Rear 22 psi

Minimum Hot F & R 34 psi


Use of Dry Air or Nitrogen

The use of dry air or nitrogen will reduce COLD to HOT pressure increase by between 50%
and 75% and COLD tyre pressures should be increase accordingly.
Please note. The FSport Event Support truck is fitted with membrane air filters which produces
95% dry air. Tyres filled with air from this source will not generate as much pressure increase
between COLD and HOT conditions as would tyres filled with normal compressed air.


Tyre Temperatures

Tyre Temperature Range 80’C- 120’C (160’F – 240’F)

Edited by chris_uk, 30 June 2012 - 10:18 PM.

[JimmyJamJerusalem]

34psi hot!!!!! Surely not Looks like I will be experimenting with tyre pressures at the National at the same time as trial running my new stage III map. People I advise caution when approaching a bright yellow VX on track

[GeorgeBC]

I start at 24-26 psi cold and ive been running 26-28 psi hot and have no complaints. Not tried them as high as 34 psi but i don't fancy that . If you want to drive mine for a few laps early on at Anglesey before you let nitrogen out of yours then you can. Might put you off superchargers though when you get out of the car without a headache . Max might give you a better idea as to what he runs as his cars properly setup.

[chris_uk]

tyre pressures mean nothing on their own, you want to get a pyrometer and start measuring temps and then altering your tyre pressure to get the temp you want.

i imagine it would be slightly tricky on your own tho.

34psi hot!!!!! Surely not

Yoko reccomend A048's at 33-36 degrees for optimum temp.

Edited by chris_uk, 30 June 2012 - 10:25 PM.

[JimmyJamJerusalem]

tyre pressures mean nothing on their own, you want to get a pyrometer and start measuring temps and then altering your tyre pressure to get the temp you want.

i imagine it would be slightly tricky on your own tho.

Chris you're a new man!!!!!!

I agree that temps are the most accurate way but that's for perfectly dialing in to a specific track on race day. Temps at edges, and middle etc, but as a rule pressures are more than adaquate for track days

[JimmyJamJerusalem]

I've actually got a laser pyrometer. Took it to every Time Attack in my kit but we never used it once (other than playing silly buggers).

[chris_uk]

well i kinda do and dont agree.. i dont believe that anyone really has tested the temps of the tyres before so how do we know that 28 hot is about right? well in short we dont, im going to buy a pyrometer and im going to see what kind of pressures i need to get the tyre to its optimum temp (well toyos advised optimum) and see how it performs. also with the tyre temp data i collect i can then see whether my guess on camber settings are decent or not. edit: I didnt know you had one, not that we would of used it even if i did too much trial and error to be done and when on a TA weekend its the last thing we want to be doing. you can come to appreciate all the hours that the big boys put in with the testing tiny bits of the setups just for the big race.. ahh, if only we had free access to the tracks

Edited by chris_uk, 30 June 2012 - 10:33 PM.

[JimmyJamJerusalem]

I can see your point mate, as I said temps are the most accurate way but who can be arsed on a trackday....? About 26 hot I'm aiming for and if my ass tells me the cars moving around too much I'll change them till it doesn't. Once I get a decent setting I'll leave it and do the rest via the shock. Regardless of what setting you try and achieve its driver satisfaction which is the main priority (even if it's just a placebo). That's how I've always done it anyway

[siztenboots]

i have put up a 7% discount code for these in the premium members forum , should be worth about £50 on the V70

[JG]

thats exactly what SImon from cornering force was doing last year at the national. Measuring tyre temperature accross the width of the tyre, and making adjustments to tyre pressure, nitron settings and blade settings accordlingly.

[cnrandall]

Most semi-slicks end up about 26-28psi hot. Jimmy - don't bother taking tyre temps with an infra-red probe, it only takes surface temps and you want a probe type that gets down to the tyre carcass. Chris-uk - I take tyre temps on every session of every track outing I do and have done for over a decade now! You build up quite a database!!

[chris_uk]

Yea, its something that i am going to start doing when i go out, granted i don't get out that often but its still nice to see how the setup i've got works on a track by track basis.

[JimmyJamJerusalem]

i have put up a 7% discount code for these in the premium members forum , should be worth about £50 on the V70

Yeah I saw that Steve good shout, does it cover the larger 'DTC' type sizes too...? thought is was just the standard sizes?

[jamiewillson]

My kumhos have been working nicely at 26-27 psi. Cold works out to about 21-22 ish. I measured temps for the first time last week and had about 70 at the inside and 60 at the outside with loads of camber.