Post track tyre condition
Discussion
I fitted a set of Goodyear Eagle F1 GSD3s 2 months ago, spent a day at Donnington on Sunday which produced a great deal of scrubbing and a little blistering on the passanger side tyres. 2 days an a few hundred miles later, the scrubbing and blistering is almost 100% cleared away and there is plenty of tread left (at least 80% of new) - however the car is all over the place sliding around roundabouts, wheels locking up under mild breaking. Is this normal? does it get better? Or are my otherwise perfect looking tyres F
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d?jazzybee said:
I fitted a set of Goodyear Eagle F1 GSD3s 2 months ago, spent a day at Donnington on Sunday which produced a great deal of scrubbing and a little blistering on the passanger side tyres. 2 days an a few hundred miles later, the scrubbing and blistering is almost 100% cleared away and there is plenty of tread left (at least 80% of new) - however the car is all over the place sliding around roundabouts, wheels locking up under mild breaking. Is this normal? does it get better? Or are my otherwise perfect looking tyres F
If the tyres have been overheated, they will go hard and never recover. Unless you have been a hooligan this shouldn't be a problem, but if the tyres have been too hot to touch they may have been cooked. On the other hand it could just be that you have got used to the level of grip from hot tyres and need to readjust to cold ones. Have you checked the tyre pressures all round?
In the Paddock, I touched the tyres, and the rubber was sticking to my fingers. I hav'nt been driving like a lunatic since coming back from Donny, but I hav'nt checked tyre pressures either. I did not inflate the tyres for the track day - so, if the have over-heated thats it for them is it?
>I did not inflate the tyres for the track
eeekk!!!
that's probably cooked them then, I would have thought..
that's one of the main reasons for "adding 10-12psi to the tyre pressures" as they say in trackday documentation...
hope they recover.
or you could keep them on another set of wheels for skidpan days
eeekk!!!
that's probably cooked them then, I would have thought..
that's one of the main reasons for "adding 10-12psi to the tyre pressures" as they say in trackday documentation...
hope they recover.
or you could keep them on another set of wheels for skidpan days
really??
everyone seems to say to up the pressures, not for grip, but to make them cope better... more pressure is less deformation, therefore less wear...
what sort of tyre wear do you get for a full day's track blasting??
edited because I just looked at your profile.... guess that thing munches tyres in a matter of seconds no matter what you do to the pressures... if you use the right pedal anyway
>> Edited by Pierscoe1 on Thursday 28th August 23:34
everyone seems to say to up the pressures, not for grip, but to make them cope better... more pressure is less deformation, therefore less wear...
what sort of tyre wear do you get for a full day's track blasting??
edited because I just looked at your profile.... guess that thing munches tyres in a matter of seconds no matter what you do to the pressures... if you use the right pedal anyway
>> Edited by Pierscoe1 on Thursday 28th August 23:34
If you are running the correct pressures on the road, then you may have to drop them for the track.
The tyres do more work on track, get hotter and the air inside them then expands. If the pressures are too high then, your tyres will balloon. You'll get less grip and uneven tyre wear!
Best way to solve any problems is to measure the temperature profile across the tyres and adjust your pressures accordingly.
Note; Clockwise circuits (Donnington) will wear lefts more and anti-clockwise will be vice-versa.
The tyres do more work on track, get hotter and the air inside them then expands. If the pressures are too high then, your tyres will balloon. You'll get less grip and uneven tyre wear!
Best way to solve any problems is to measure the temperature profile across the tyres and adjust your pressures accordingly.
Note; Clockwise circuits (Donnington) will wear lefts more and anti-clockwise will be vice-versa.
in the stuff I've had from trackday companies.. where it tells you to "wear long-sleeved clothing", "must have a helmet" etc etc, they always say "advisable to raise tyre pressures by up to 12psi"
yes you get less grip, but with the tyres at road pressures, all the moving around of the sidewalls under the increased loads of track driving overheats the rubber... as Ijaz seems to have found out..
yes you get less grip, but with the tyres at road pressures, all the moving around of the sidewalls under the increased loads of track driving overheats the rubber... as Ijaz seems to have found out..
Ideal tyre pressures are very very dependent on the car and how it is driven. The idea behind increasing the pressure is to stiffen the sidewall so that the tyre does not starting distorting and also to help stop the tyre overheating.
Dropping the cold pressure means that the tyres have to get hot before they start to sort themselves out. Most track dayers raise the pressure. If the car is a TVR, the cold pressures are almost half that of a Porsche 22 vs 36ish. Putting 12 lbs in on a TVR will make the car handle like a Trabant and a trip off the circuit is almost guaranteed. Equally running on normal pressures will kill a set of tyres because they will overheat.
The best advice is to talk to someone experienced who has the same car as you and take it from there. Try adjusting the pressures and get a feel for how the car handles and what sort of temps it gets to.
From the description, I would say the pressures were too low and the tyres were cooked. In my experience of Goodyears - and it was some time ago - they end up having the grip of wet vinyl when that happens. I don't know if the new ones are any better. It might improve as the top layer gets worn down.
Dropping the cold pressure means that the tyres have to get hot before they start to sort themselves out. Most track dayers raise the pressure. If the car is a TVR, the cold pressures are almost half that of a Porsche 22 vs 36ish. Putting 12 lbs in on a TVR will make the car handle like a Trabant and a trip off the circuit is almost guaranteed. Equally running on normal pressures will kill a set of tyres because they will overheat.
The best advice is to talk to someone experienced who has the same car as you and take it from there. Try adjusting the pressures and get a feel for how the car handles and what sort of temps it gets to.
From the description, I would say the pressures were too low and the tyres were cooked. In my experience of Goodyears - and it was some time ago - they end up having the grip of wet vinyl when that happens. I don't know if the new ones are any better. It might improve as the top layer gets worn down.
shpub said:
From the description, I would say the pressures were too low and the tyres were cooked. In my experience of Goodyears - and it was some time ago - they end up having the grip of wet vinyl when that happens. I don't know if the new ones are any better. It might improve as the top layer gets worn down.
Sounds about right to me. I hope they will get better if they wear down a bit. Now where is a good quiet roundabout??
[quote=Pierscoe1
that's one of the main reasons for "adding 10-12psi to the tyre pressures" as they say in trackday documentation...
[/quote]
Speak to some regular track dayers in your specific car, but to me thats a sure fire way to end up in the armco, i checked tyre pressures at cold before a session once & after and on top of the normal pressure (32psi) the left hand front had gone up 9psi! so if id have added the recomended 10-12psi and it had then heated up to 9psi over that I'd have been looking at potential 50+psi!!
So assuming i diddnt get a blow out first it would have been a surefire recipe for an 'Hello armco nice to meet you my name is iguana' type moment
that's one of the main reasons for "adding 10-12psi to the tyre pressures" as they say in trackday documentation...
[/quote]
Speak to some regular track dayers in your specific car, but to me thats a sure fire way to end up in the armco, i checked tyre pressures at cold before a session once & after and on top of the normal pressure (32psi) the left hand front had gone up 9psi! so if id have added the recomended 10-12psi and it had then heated up to 9psi over that I'd have been looking at potential 50+psi!!
So assuming i diddnt get a blow out first it would have been a surefire recipe for an 'Hello armco nice to meet you my name is iguana' type moment
I posted similar questions about tyre pressures as I founf my griff 'twitchy' after adding 2-3lbs, because after 2nd session they were showing +10lbs on the outside and +6lbs inside...
Most told me to just get on with enjoying the day, which is fair enough but I had to have a fiddle
... I dropped the pressure to equalize the sides to +2lbs over road and found the griff just gripped like hell and was very stable...
Incidently, have done 3 track days and 4000 road miles on same set of tyres....
Most told me to just get on with enjoying the day, which is fair enough but I had to have a fiddle
... I dropped the pressure to equalize the sides to +2lbs over road and found the griff just gripped like hell and was very stable... Incidently, have done 3 track days and 4000 road miles on same set of tyres....
I know this is an old thread, but just thought I might share my experiences regarding tyre pressures. My first track day many moons ago in a 968 CS, resulted in the tyre pressures on the outside tyres going through the roof & 2 spins on the same lap, this mystified me since I had entered the corners no faster than before. It was only when I checked that I realised the pressuures were so High ( how about 60 PSI ! ).
Subsequently I have started with standard & lowered after each session. However, recently I have added 4 or 5 PSI over standard as a starting point. This has resulted in much more stable variations rather than the vast increases & subsequent deflating. The realisation set in that the tyres must be distorting & therefore overheating with standard pressure, resulting in lack of consistancy in lap times. Since trying this I have noticed a vast improvement in handling & grip consistancy over a session with the tyres only gaining a few PSI & about 1.5 seconds quicker per lap on average. This also applies to use in the wet. Too low a pressure will close up the tread & you will have a shopping trolley on ice.
Subsequently I have started with standard & lowered after each session. However, recently I have added 4 or 5 PSI over standard as a starting point. This has resulted in much more stable variations rather than the vast increases & subsequent deflating. The realisation set in that the tyres must be distorting & therefore overheating with standard pressure, resulting in lack of consistancy in lap times. Since trying this I have noticed a vast improvement in handling & grip consistancy over a session with the tyres only gaining a few PSI & about 1.5 seconds quicker per lap on average. This also applies to use in the wet. Too low a pressure will close up the tread & you will have a shopping trolley on ice.
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