Changing wheels when hot at trackdays

[Fraser.J.]

I've got a full day open pit on Saturda,y, temps are going to be high and tyre wear is going to be at a maximum, I'm running AO48s and looking to keep on top of the wear and swap them around regularly on the day.

What's protocol for tightening them up with my studs are hot? Don't want to be stretching them!

Thanks Fraser

 

[Budgie]

No need to swap them around tbh.

Just make sure the pressures are right.

 

[Fraser.J.]

I do.

But this happened after last time

I can only put that down to heat?

 

[Budgie]

Excessive wear down the centre suggests the pressures were still too high?

What kind of psi do you run at?

 

[Fraser.J.]

That was at 30, I check them regularly, that's the front near side which takes all the anise at knockhill as its mainly right handers

 

[mark smith87]

I never swap tyres around. No need at trackday. Just make sure they're I'm good condition before you go and don't over-inflate them. 2.0 bar max.

 

[...]

i would be running them lower than 30psi they have stiff sidewalls so should be no problem and they have been well over inflated looking at the way they have worn .....


​check hot presures ,and try and check temps .

 

[Fraser.J.]

I check my pressures every few laps until there up to full temp.

I still wouldn't mind swapping fronts and rears to even it out, so what's protocol?

 

[bob the builder]

30 psi is way too high, i would think about 20psi to be about right.
when i had my gtir used to run at 18 psi and that car is alot hevier.

 

[TheEvilGiraffe]

If you're putting enough heat into the studs to stretch them with a 2ft long torque wrench, you've probably got bigger issues than a bit of tyre wear

I'd be starting off at about 20psi and seeing how warm they get. Wouldn't want to run higher than 28-30 when at full operating temps.

If you really feel the need to swap them over, just follow standard procedure. If you're really worried, do a few laps then come back in and check torques and pressures before carrying on.

Remember to change the pressures front >> rear when you swap wheels over !

 

[Fraser.J.]

30psi is my hot pressure.

I'm not a trackday noob, this is my 8th this year and I done 5 last year.

I'm just double checking as tony from burpspeed said don't torque when hot as you can stretch the bolts/studs.

I've not had any issues with wear on my first
6 but this was only a few weeks ago when it was very hot 25 degrees and the forecast for Saturday is the same.

 

[...]

I was told by yokohama the optimum pressure for an 048 was 21psi hot for a base setting ... then look at tyre temps

 

[Steve]

21 hot?

Outside air temp is 30 for Sat, without running on track.

How do you expect 21, am I missing something?

 

[TheEvilGiraffe]

Blonde moment ?

Degrees celsius =/= pressure.

pV=nRT, or something like that...

 

[Fraser.J.]

Pressure wise I run 30psi when the tyres are up to temp, after approx 5/6 laps I check and check anytime I come off straight away.

 

[.GAZ.]

Don't do a 50 minute session.. LOL!

 

[Tony Hunter]

That does look like it been slightly over inflated as the centre is worn.

That looks like a Direzza to me, our man from Dunlop told me 28-30 hot, as long as there is a 10deg temp range across the surface.

You can swap them around if you like, but you would better to do it at lunch time, when they have been left to cool for a bit.
​

 

[Tony Hunter]

Don't do a 50 minute session.. LOL!

​But they were rubbing, weren't they ?

Anyway, 50 mins is far too long.

 

[Fraser.J.]

That does look like it been slightly over inflated as the centre is worn.

That looks like a Direzza to me, our man from Dunlop told me 28-30 hot, as long as there is a 10deg temp range across the surface.

You can swap them around if you like, but you would better to do it at lunch time, when they have been left to cool for a bit.
​

It is a direzzas, one of the ones I got from you nearly a year ago!

Ill drop my pressures to 28 on Sat and see how I get on. Will try keep to shorter sessions aswell,

Ill keep an eye on wear and aim for swapping at lunch.

 

[Bobby.]

Tony, on a side note, with a clio on standard wheel bolts, would you say it's right on wrong to check the torque of them when you come back in the pits?

When I had my mk2 I use to do this as well as check pressures when everything was hot and at 120nm I would usually get a little give in the bolts before the toque wrench clicks again.

 

[Tony Hunter]

Of course you have to check them.
I don't want people's wheels falling off.
But just think about it, tbey will gradually stretch if constantly tourqed up when hot.

On a road car, how often do wheel nuts/ bolts get checked in a cars lifetime, not many.

Even on the race car, when the transport wheeks are out on, they aren't tourqed up, and thats with expensive studs and nuts.
Just be sensible with what you are doing.

 

[Adam G]

I normally do a non torque wrench check after a couple of sessions. Purely to make sure none are loose, so a gentle test with the bar. Then a torque check before starting again, after lunch break.

 

[Bobby.]

Sound advise chaps, basically what I would do. Just wanted to get your opinion on it that's all.

I find after the first couple runs they settle and don't move any more, but yeah would definetly check them a couple times over the day.

 

[.GAZ.]

​But they were rubbing, weren't they ?

Anyway, 50 mins is far too long.

Yeah, rubbing in various places.

 

[Martin.]

I've never torqued my wheels nuts and I've never had any problems with bolts. I just test them by hand a few times per trackday.
​

 

[Sam@NP]

Of course you have to check them.
I don't want people's wheels falling off.
But just think about it, tbey will gradually stretch if constantly tourqed up when hot.

On a road car, how often do wheel nuts/ bolts get checked in a cars lifetime, not many.

Even on the race car, when the transport wheeks are out on, they aren't tourqed up, and thats with expensive studs and nuts.
Just be sensible with what you are doing.

Why transport wheels?

​Because race car.

 

[Tony Hunter]

Why transport wheels?

​Because race car.

Thats right young Sammy, I never leave the race rubber on the car, they come off straight away and the wet's (r1r's) go on.

 

[Sam@NP]

Thats right young Sammy, I never leave the race rubber on the car, they come off straight away and the wet's (r1r's) go on.

Same Our transport wheels are narrower as well so more lock can be used.