What do you make of this tire wear?

[PeanutinCA]

These are now my rears, they were on the front when I had that push when we ran Willow with NASA. These were my rears at Buttonwillow and I wonder if that had anything to do with the rear handling. Especially as the right side would step out more than the left tire and the wear is more severe on the right tire?

 

Rear Left;

 

Rear Right;

 

???????

 

P.Dilly.

[924RACR]

My initial reaction was overinflation, looking at the bottom pic - but then I realized it's much more localized, not to mention off-center. I'd almost be concerned about what the belts are doing. Have you shown these to your tire rep?

[944-Spec#94]

Actually looks good to me? No cord yet!

 

Seriously...

How many sessions? Have you been rotating the tires after each track day? My tire wear is mostly pretty even across all 4 tires if I rotate them after every track day. If I leave them too long in their spots they get uneven simply due to course and which tire it wears down more.

 

You have alot of built-up rubber so it is hard to see the exact tire sureface.

 

To me those look to be near the end, but still inthe sweet spot. Remember that these toyo's will grip very nicely to the point they are old. Then they lose grip, but still have rubber. On mine I have yet to see cords.

 

 

BTW... The buldge pattern seems normal for the tire I have run that are near the end of their life.

On my two sets of tires that I have used up both were worn down like that and as they got older got a bit faster. Last couple sessions were a little dicely, but the tire were faster than snot IF you could keep them under you. Then 1 or two sessions later they just got slick. This was after 40 some heat cycles.

 

What pressures are you running. Hot & cold? Rotoations? How many street miles?

 

[jjgrow]

I share Joe's opinion - I have a set that look pretty similar, bulge and all. Ran them a couple sessions at BW last weekend but one wheel is out of balance again and I had a bad shimmy so I pulled them off and ran my practice tires. The right side will show more wear at BW when running CC as all the long-duration, high-g corners are left handers (like the left side at Willow).

[Spec-944#70]

Look just like mine!!

[PeanutinCA]

So you guys have these bulges? The inner 2/4 look ok to me, square, meat left on the tire. The next 1/4 seems to have worn excessively and then the outer 1/4 is rounded off like not enough camber or perhaps not high enough temps?

 

I started asbout 34 cold, ending about 41 hot? I had them on for Willow up front, swapped sides for the next Willow. Put them to the back for Fontana but the car ran so badly they didn't get a lot of miles. Then left them as were for BW due to running the other direction to the last Willow. The photos don't quite show it but those levels are quite significant? Oh and my fronts are NOT like this. Not this bad anyway?

 

They look odd to me as my other tires didn't wear this way?

 

P.Dilly.

[Tim Comeau]

**This posting reconstructed**

 

1. You said this developed at Willow , when you had a big push. Clue #1?

2. You recently changed out the front A-arms. Did you get a good alignment afterwards? What camber are you running in the front? Toe?

3. Your pressures seem in the ballpark as per TOYO TIRES- high 30's to low 40's when hot, but if you were pushing, as suggested by the excessive outer wear (rounding ) I'll bet the tire was distorting. That is, the side wall was buckling in, causing the working surface to bulge out and thus wear more.

I've seen this before on the BF Goodrich Comp TA-R1's several years ago. Those tires, when under-inflated, would develop what we referred to as "the groove of death" -a ring of cord showing about 1/3 of the way in from the outside edge. The rest of the tire was fine. It looked like they were OVER-inflated. It was explained to me that the side walls on that tire were really stiff and when it wasn't inflated properly, which adds to the "structure" of the tire, they would fold under. Number of belts in the sidewall vs. number of belts in the tread?

I'm not saying I've got the answer here, but this might be a part of it. I wonder what the guys at TOYO TIRES would say? I HAVE seen this on some of my tires, too

Edited June 12, 2004 by Guest

[PeanutinCA]

I shrunk the images. Is that better?

 

That ring of death sounds interesting. I remember you tell me that before. I'm think back to that first weehel when I changed my own A-Arm, just to make that first clinic race. Then a good alignment with Alarcon and back to Willow. By the time I got comfortable with the car, it was stuttering, which slowed me down. But I was entering the corners faster i.e. turn 2 and was discovering the push. After that weekend I noticed the "groove" so to speak.

 

It's done those 4 weekends plus the driving to and from. I've seen similar wear before, but not as severe as this.

 

P.Dilly.

[Tim Comeau]

Dylan, the first time I got on the thread this morning, the picture shrinking worked. Now it's back to "slide bar city." ???????????

[Tim Comeau]

Hey guys, just thought I'd dig up this thread because of the tire pressure gauge issue. The Dylan pics are what I experienced too. My tire gauge was reading zero at rest, but was 5-7 pounds off. My tire pressures were low. 32 HOT! Check your gauge against another known good one.

[PeanutinCA]

I had my alignment checked again. It was a little out in the front, which is where the tires started out. But I think the damage was done the first weekend when I changed my own A-arms and didn't check the alignment. It was very Toe'd in. The guy doing the alignment, who I'd not spoken to before commented as I was looking under the car, "those tires are gone". Who knows? I'll get a new set and start scrubbing them in. They certainly exhibited strange handling characteristics, letting go half way through the turn at BW?

 

P.Dilly.