Track day tyre pressure

[Baz2004 0]

I’m running standard G60 15’ steeles tomorrow for a track day, does anyone know what tyre pressure to go with?

 

Last time out I lowed the pressure too much on the front and I had a tyre come off the rim after 7 laps.

[corozin 0]

Just take about 2-3psi from your normal pressure. That should account for the heat buildup.

 

It will also help preserve your rubber a lot if you try to be smooth on corner entry and feed the power in as you pass the apex. Don't try and chuck it about too much.

 

And if you have them, take spare front brake pads. Have a good day & hope this isn't too late to read

 

 

John

[Baz2004 0]

Yeah im going to start off with 27psi on the fronts and see how I get on, ill be keeping an eye on them as the day goes on.

 

I think the main problem I had the last time was heavy breaking into corners, I was on the brakes heavy quite late on turn in.

[corozin 0]

I've only just noticed in your sig that you're running P-Zero Neros. With track tyres you need to be even more careful about the transition from braking to turn in, as it's easy to shred the edges that way.

 

I shared this problem with an instructor at Combe a while back and the advice was basically to try and do more of the braking earlier and soften your braking pressure as you reach the turn point. This also helps the car settle a bit and takes the weight off as you start to turn.

 

As you turn in, try not to 'grab' the wheel too much but try to feel it into the corner. The steering will definately reach a point where it starts to load up a lot more but you need to resist the temptation to force it further. This is the point where you'll be just scrubbing the tyres if you go beyond it.

 

From there, use the speed/throttle of the car to adjust the attitude into the bend, even holding on half throttle if necessary to stop the steering loading up again too much, before finally pushing through and releasing the lock as you fall out of the bend.

 

All sounds rudimentary enough, but this really is the quickest way to run with more track based rubber like yours, plus you'll preserve the tyre at the right operating temperature and preserve it for far longer. Although it's a little less dramatic than screeching about, you'll also be using the grip available properly and carry a lot more speed than is possible on normal road tyres.

 

Using this style a few weeks ago I ran a fairly fresh set of R888's at Combe for over 2 hours of hard track time (over 120 miles) on the VR6 and still had tread legal enough to drive home with. I wasn't hanging about either!

[Baz2004 0]

Had a good day out the car went well all day, took a few laps to get used to the new resurface parts of the track (mondello), stayed dry for most of it which was a help.

 

Managed to get my turn in together as the day went on, put the car through it paces in the afternoon, I went with 30psi all round to start off and dropped the front from 34 back to 30 as they got warm every few laps.

 

I got some good laps in with help from my co-pilot (rmn) I was very impressed with the Bridgestone road tires, they had plenty of grip and showed hardly any signs of wear after a day out.

 

The new 25mm brake MC is giving a good pedal now even after a few hours on track the pedal is still good, that blue racing fluid has also improved the spongy feel on the brakes.

 

All in all a good day out, managed to keep the car in shape and enjoyed the time out.

 

Only downside was a small oil leak from the rocker cover gasket, also some oil leaking from the mrk iv cap I recently put on. Looks like its back the drawing board on that front !

 

 

 

More pics available http://public.fotki.com/speedy/2007-events/maytrack/page6.html

[dinkus 10]

It's also worth noting that most tyres have little arrows on the edge of the tread - these can be used to check your tyre pressures.

 

If you scrub 'em off then put your pressures up and/or back off a bit through the corners because the tyre is flexing too much and you're scrubbing the side of the tyre away.

[Toad 0]

Good tippage Dinky!

[dinkus 10]

And worth adding that if you scrub 'em off by too much your tyres will start delaminating and you'll die. Possibly.

[vwdeviant 0]

And worth adding that if you scrub 'em off by too much your tyres will start delaminating and you'll die. Possibly.

 

Ah the voice of cheer.. :lol:

[corozin 0]

So Dom by that measurement - the time 5 years ago when I scrubbed not only the edge of my tyres off, but also the top half of the Toyo logos on them - that was bad ??

 

 

[StuartFZR400 0]

Where did you go? (cant follow link)

What engine work you got done to produce what power? Didnt get seen off by too many other brands?

You've got the blue brake fluid, but what other brake mods? Just curious as the standard are so poor on mine for fade.

 

As for the pressures it alll about a bit of experimenting. There are loads of good sites on the web to give an idea of what to do with them. Glad 30/30 worked well for you, but didnt understand the reducing pressure to reduce temp. As for asking for a general pressure to use; we're all different on here; you've got different tyre sizes (even on a 15 rim) on different sized wheels, with different brands. These Rainsports are fine and all, but need that extra pressure just to stop the wall flexing too much. Then you've got tread wear - loads of tread will mean loads of movement + heat. You can play with pressures on track, just changing the rear should make a huge difference as you start to play around with the slip angle. Enjoy!

[dinkus 10]

It's also worth mentioning here that it's a very bad idea to take your car on a track with a nice new set of tyres - use the day to kill the old ones and get them changed before you drive home.

 

If you thrap road tyres with more than 6mm or so of tread then it's highly likely that you'll rip the tread blocks clean off the tyre. Even if you don't, the tyre will have a fair bit more flex in it and not feel as responsive as it would on semi-balds :)

[corozin 0]

It's also worth mentioning here that it's a very bad idea to take your car on a track with a nice new set of tyres - use the day to kill the old ones and get them changed before you drive home.

 

If you thrap road tyres with more than 6mm or so of tread then it's highly likely that you'll rip the tread blocks clean off the tyre. Even if you don't, the tyre will have a fair bit more flex in it and not feel as responsive as it would on semi-balds :)

 

I agree with that Dom. In my case the potential effect was even more pronounced as my R888's were only 5 weeks old (only about 600 miles on them) when I went to Combe in April.

 

That all said, if you do find yourself in the situation where you are running fairly new road tyres at a trackday and can't avoid using them, then dropping 2-4lb off the pressure and following the guidance on driving I've posted above will make a huge difference to your rate of tyre wear.

 

The first year I went to Combe, I tore the sidewalls of my T1-S tyres to shreds, but as my knowledge grew the tyre wear lessened and I wasn't destroying them anymore. Going out for a whole day on track rubber requires another level of control if you want to preserve them I've found, but the additional performance is worth it IMHO.

 

The other thing which I havn't mentioned but which helps the wear rate a lot is the fitment of strut braces to the car, particularly at the front. This stops the geometry moving too much under hard cornering, and keeps the face of the tyre flatter. I didn't have mine fitted in April but it will be on soon, along with some nice coilovers care of Mr Brookes :)