tyre pressure for the track

[Jimbo2000]

gday, just about to go to bed so dont have time to search..

i've got 235,45,17's

bearing in mind i gotta drive for 2 hours to get to the track what pressure should i put in?

tyres will be COLD when i pull into the servo before heading off.

Thanks

[Laurence]

Just remember it is easier to take out air out than it is to put it in!

For road tyres I used to just put in the maximum pressure written on the sidewall.

Then after the drive take them back down to the maximum pressure on the front and 4psi less on the rear. Which was usually 44psi front 40psi rear warm.

Then I would play with them after each session depending on what the car was doing.

With semi-slicks I found that lower pressures worked better, I presume because the stiffer sidewalls meant that you weren't using the air to "stiffen up" the tyres.

Anyway, it worked for me, but I am not Sydneykid... *dreads his reply*

[Laurence]

What on earth does this have to do with drag or drift????

[Snowman]

What on earth does this have to do with drag or drift????

I was wondering the same thing!

Anyways... as mentioned by Gojira I found with normal street tyres that around the 40psi works well. I tested this just recently at Winton where I started with 40, then went to 30 which was BAD, then tried 35. But 40 was the best.

For the sem-comps - despite being told by the guys that sold me the tyres that 40psi was optimal - I definitely get better results at 30psi. Infact all the guys I know that run semi's at the track - whether Bridgestone, Dunlop or Advan - all use 30psi.

[Snowman]

BTW - one little piece of advice that you can choose to ignore if you like is to go and buy yourself one of those little 12V compressor pumps from your local autobarn/supercheap etc. Different tracks will require different "cold pressures" and by having one of these it will help you easily inflate/deflate tyres to reach your optimal pressure in each tyre after each warm-up session. It allows you to experiment a bit as well.

IMO they are a great thing for about $40.

[Duncan]

I know this is already too late for you :Oops:

I'd take about 40 hot for road tyres too. Don't worry too much about cold temps if you are looking at a track....left, right, front, rear all tyres will heat up different amounts, up to 8psi in a FWD car!

R tyres tho, I've personally found that different tyres work at different temps, the bridgestone re55s I was running at about 32, while the Dunlop formula rs at 38. And the Kumhos we used to use were best at around 44! But I guess all you can do is try different pressures and find out what works best.

As for setting them I always go higher, do about 2-3 laps to get them nice and toasty and then let them down. Wakefields the only track in NSW with a compressor (I guess poor old Eastern Creek can't afford one?). Otherwise the 12v ones are nice and portable

[r33_racer]

i know im nearly 2 years behind here...but ive found that with re55s weve run 26 on the front and about 24 on the back cold. In qld, they tend to grow about 4-5 psi, so hot were getting about 30-32front and 30back. Thats worked the best for us. Trying michy s8a's soon, will be interesting to see what they need.

lol wonder if anyone even reads this. Its an old thread.

[johnGTS-t]

im reading for one!!

i did a track day last sunday and i started with 30 F 32 R

then to experiment, i let our around 8sec's of air which may of been 8-10 pounds and i went quicker

ive only got some Yokohama's and Sliverstone road tryes on.

im planning on getting some bridgestone RE55's

[baboo]

For RE55s, the optimal HOT temp is 34~35psi