Toyo Sidewall wear

[s_and_m]

I have fitted Toyo T1-Rs to the front of my Cooper S and T1-Ss to the rear. On a recent track day I noticed that the side wall of the front tyres has worn quite markedly, despite the tyres being up to temperature and pressure.

The wording on the sidewall has literally worn away and there are rub marks running right round the wall. Rear tyres are fine.

Anybody else notice this - is it a function of low(ish) profile tyres 215/40s or is it just a Toyo thing?

cheers

s

[moonshine]

no problems with the sidewalls on my 205/40 T1-S - with about 15k on them, though no trackdays
The tyres have worn more at the outer shoulders than the inner shoulders, but i'm sure that this is to do with agressive cornering more than anything

Gerry

[laptop]

The wear on the sidewalls is an indication that during cornering, the tyre is "rolling" on the rim, allowing contact of the sidewall with the road surface.

One reason for this is frequently to do with the size of tyre (width) and the width of the rim on which it is fitted.

In very heavy cornering, as per track days, this is a fairly normal event.

[RVW]

SLOW DOWN

[s_and_m]

Quote: Originally Posted by RVW

SLOW DOWN

Will practice this new concept, doesn't sound like much fun though

S
And laptop, thanks for that - perhaps I should have gone for 205s rather than 215s for lateral stability!

[pocketrocketowner]

Side wall wear is a sure indicator of low tire pressure. Like the man said, you are "rolling" them and a sure cure is higher tire pressure as it = stiffer sidewalls. Just a thought....

Hope this helps

[s_and_m]

Quote: Originally Posted by pocketrocketowner

Side wall wear is a sure indicator of low tire pressure. Like the man said, you are "rolling" them and a sure cure is higher tire pressure as it = stiffer sidewalls. Just a thought....

Hope this helps

I was running the fronts at 31 and the rears at 29, air temp was 13 degrees, guess I was still in runflat mode! What sort of track pressures should I be looking at for 215/40s?

Cheers

s

[moonshine]

pressures are so subjective.....the best way to fine tune them is with a pyrometer as this will show which part of the tyre is overheating, and whether more or less pressire is required...the aim is to get an even heat distribution and the pressure required would vary front to rear, left to right, depending on the track you are on.

Quite how this will stop the sidewall scrubing i'm not sure, but i would guess a pyrometer would show the outside of the tyres were much hotter than the centre or inside, therefore more air is required to stiffen the tyre and even the temperatureout. Once too much air was added, the centre of the tyre would be the hottest, indicating that some air should be lost.
Gerry

[laptop]

I actually conducted some genuine tyre testing yesterday (part of my job).

Very much in brief S&M, I would be concerned if you are achieving wear to the tyre wall lower than half way down the side (that being nearer to the wheel rim than the tread blocks). I found the mid way point to be the limit of the wear that my testing produced (and this really was very hard testing indeed). Anything below the mid point would worry me that there was likely to be rim contact, not a good thing, and frequently a prequel to rolling the car!!

My initial thoughts with regards to tyre pressure "v" tyre heat.......I don't specifically see how this will achieve a constant tyre temperature across the entire tread face. The very dynamics of cornering means that the outside shoulders get loaded, and therefore this area tends to show increased temperatures.....something that "the hand placement test" confirmed yesterday.......and again, fronts will be hotter than rears etc etc etc.

The surface of the track makes a considerable difference also. Airfields for example tend to be made of high friction surfaces. Again, in very incorrect terms to try to explain in layman's terms, if the tread blocks "hold on" to the surface at higher speeds because of the friction before beginning to slide, then the sidewall will roll more than a surface where the tread blocks slide across the surface sooner or slower. So, this sidewall wear is again more noticeable from trackday action than highway action.

I wouldn't worry too much S&M, its what I would expect to see. Oh, and about 4psi above road pressures is a good "rule of thumb" for tracking IMHO.

[s_and_m]

My wear is on the top half of the tyre wall and the rims are undamaged - so I think I was a fair way off rolling the car. BTW - the exercise that I think did the most damage was a high speed cornering exercise designed to promote rear wheel slides (or drifts) in rear wheel cars. To effect the same thing in my S I had to resort to liberal use of the handbrake!

It wasn't a hooligan exercise, the idea was to teach car control on lift off oversteer Great fun but murder on the tyres

Amd thanks for the nice simple advice re track day pressures!


S

[RedUn]

i'd say u need to run sum camber ont he front if yer going to do more track days

shud help the wear and give a bit more grip at the front end

[s_and_m]

Quote: Originally Posted by RedUn

i'd say u need to run sum camber ont he front if yer going to do more track days

shud help the wear and give a bit more grip at the front end

A quick blat through my favourite B road test track (all at legal speeds officer! ) saw a drop in front tyre pressures - meaning the seal was broken during cornering or I have a slow puncture!

A little bit of camber may help in those extreme cornering moments that the Mini just loves!

Now to find an easy to use camber plate and coil over set for less than the cost of a 2 week trip to the Maldives!

S

[pocketrocketowner]

Your hot tire press should be at least 35 PSI front, 37 or 38 rear (I imagine you like it snappy )

Pyrometer use for wasting yer money: as a tire pressure indicator
Proper pyrometer use: fine tune canber/toe according to the temp profile.

Hope this helps