I had a track day at PPIR yesterday. The track is very hard on the right side and especially right front tires. I could fel my tires overheating and should have come in, but I was having way too much fun to do that.
Anyways I blistered my RF tire. Upon reflection I wonder if it didn't blister because of the ABS. I remember getting too hard on the Stoptechs in the hardest bracking zone (4th gear to 2nd gear) when the tire was feeling hot. The blisters are somewhat evenly spaced along the same spot around the circumference of the tire. I know that you can flat spot race tires with non-ABS equipped cars - would the ABS cause the tires to blister like this?

 

heat build up causes blistering. you have exceeded your Rf's capability in heat dispersion. time for higher performance hoopies!

Alex

 

Sorry to hear about this. How long are your track sessions? Ours are about 15 to 20 minutes each which is about long enough to drive without worrying about overheating and blistering. Heat is the enemy for brakes and wheels/tires. Which tires did you use and were they newer or had many heat cycles on them already? Some tires are known to take longer to warm up so that might be an option for you.

Safest thing to do is to come in for a pit stop and exercise some damage control just as a precaution. Or be prepared to buy more tires early. Or buy in sets of 6 not four.

Hey Alex,
In that case can we use a water spray bottle and spray some water on the "Hot" tire to cool it a little (not on the brakes)?

 

Obviously they are caused by too much heat. But, couldn't the shear forces from the ABS pulsing under braking be the last step in the process?

Higher performance tires?? I'm using Avon TechR's now - I think I just need to recognize that the tires are overheating sooner, control my testosterone, come in or slow down.

 

Rf = Runflat or Right front?

LOL right front

Alex

 

I've found my passenger front gets much hotter than all my other tires, too, regardless of whether I am autocrossing or on the track - even with different course layouts or running courses in different directions... It's odd, but it seems like that rotor and caliper run considerably hotter than the driver's front, too...

 

Did it again - I really need to learn how to control myself! This was at an ACNA event at Heartland park. 60 degree day, running 2.4 degrees camber, 41 psi (hot), Leda's at 8 out of 24. The second session of the day was a 30 minute session, got too aggressive, felt them going off a bit - should of come in.

Here's a pic of my right front tire - the others were OK. This tire has 4 1/2 trak days and a couple of autocrosses on it. The blister is on the outside edge.

 

I'd almost say that's a flat spot. If it blistered, I would imagine you would see a ring around the whole tire.

But, if it's not, you should really get a tire pyrometer and check the tire temps after a session. If the outside is getting that hot, you need more camber, plain and simple.

 

Mark, I don't know what plates you have, but if 2.4 is not enough, you might be maxed-out. Randy's new Aurora monoball plates do go out to 3.0, so that might be an option for you, assuming you don't have those plates...

 

There's a couple of other, smaller, blisters around the circumference - the same distance from the edge as the large one. I'm suspecting that these might occur from braking - but with the amount of camber I run would the blistering occur where the tire has the most contact with the road, or wear there is more slippage?

I can add more camber - at least there is room in the strut slot - but I thought the limiting factor was the spring hitting the body inside the fender well.

Tony, per your pm, I do have a rubber bump stop - but haven't had a chance to measure the shock yet.

Here's a different pic, you can see a couple of the other blisters...

 

Hey, no need on the shock body measurement Mark. I got a few confirmations of the 11.5" figure. I'm trying to visualize your wear issue, and what might cause it...

I just pulled-up a map of Pike's Peak, and it's an oval. I'm guessing that you were going around clockwise, right turns? I wonder if you might be bump-stopping on your FR, even just a little. And if so, would that contribute to this issue...

Randy should be back in town tomorrow (from LA), so you might want to run this by him.

 

Tony,

We were on the road course a PPIR, but it is mostly left hand turns and I was told by an SCCA racer friend that it is hard on RF tires.

Heartland also has a lot of lefties.

I think I need more camber, to disengage the ABS (and/or get better at threshold braking) and force myself to get off the track when the tires start going away on me.

Calling Randy's a good idea (if I can reach him).

 

At first, I also thought "flat spot" but then after looking at second picture I'm not sure. Looks like could be both flat spot and camber. Outer ring is gone so wear is more to the outer portion of the tire. Also on second picture I can see the upper area that does seem to be a blister. If you do infact have 2.4 degree neg. camber, I'm not sure another .6 is going to help all that much but, may be worth a try. I'd also dial in as much caster as you can. Could something be happening to allow the camber to change under load?
Finally, rotate r/f and l/r. When that outer ring starts to disappear, you know its time to quit with that tire . Sure don't want a blow-out on right front... that will cost more than just a new tire

 

I was thinking along the lines of apexer, that mabye camber might be changing, namely under load. I was sort of alluding to this with my bump stop inquiry...

To see if you are hitting your bump stops, put some putty or something comparable on top of them. I did this with some painter's putty, and was able to mash it just in my driveway. Something worth exploring as it's relatively easy, and not that time consuming...

But then if this the situation, why not on both sides? A travel/bump stop issue should be identical on each side, assuming they are adjusted equally. I might have just shot-down my own theory...

Oh well, please do keep us informed.