Cal Club Autocross Forums

I was under the impression that tires with a tread wear rating of 200 plus would not require water cooling after a run. However I just read a post by Samuel Brownfield that said that he had overheated the shoulders on a set of tires which I believe are Hankooks.

How do you know if a tire has been overheated? How badly does that affect traction. What are the conditions that indicate the tire must be water cooled? Any insights would be greatly appreciated.

And wouldn't it be great to drive your car though a shallow water trough after a run to cool them. No more water sprayers and it would speed things up considerably.

If they are too hot too touch, they need to be watered.

I personally like my street tires a bit colder then "to hot to touch".

Taking Adams concept of touch temp (vs. measured temp)... IMHO if they are warmer than a hand you would want to continue holding (ie would make your hand sweat), then I cool them.

I gauge mine by performance. For my big fatty car I can usually tell on Hankooks when they need water cause it gets really greasy and slippery and i have trouble putting power down or the understeer is just hopelessly out of control. After a couple events you start to get a feeling for when you need to start watering based on run length, conditions and surface. Like Adam said, if it burns to touch, probably need water.

I need water on Toyo pixie dust tires usually about 600 feet before the finish on the first lap of the first driver.

Depends on the tire/car. On my RS3, I never cool em at autox, they need a bit of heat to work right. On the star spec z1 they needed some attention on hot days, especially when it was sunny and the pavement was hot.

Adam Tarnoff wrote:If they are too hot too touch, they need to be watered.

If they're too hot to touch, you've already missed your window.

I think it was said, but over heated tires feel 'greasey' and can lead to blistering. This usually leads to significantly slower times, but I've heard one expet driver say his 'greasy' Azenis made him faster.

Hankooks needed more heat than other typicals to work right, say by your 3rd run if you're alone and will only over heat with a single driver on the hottest of days. Toyos start to over heat immediately, but are ready to race out of the box. Dunlops and BFGs are right down the middle.

Bigger cars over heat faster, choppy driving over heats faster. I wouldn't rely on a 'handling feel', as by the time you feel it you're slowing down. We hand feel our tires and decided to water or not based on how many runs we have left, trying to keep in that sweet spot throughout.

The most serious can get this down to a science with a pyrometer. Probes are better than IR.

Jay W

When I cooked my RS3s I was running fun run after fun run without a cool down, they got greasy, I did some spinning... I basically was abusing them pretty badly. I'm pretty new at this and was pushing hard. I will be watering from now on when I get some new rubber.

This is what tires that aren't meant to handle aggressive driving even going through a gallon of water for 2 drivers on mostly the fronts. Tires are 235/45/17 on a '15 wrx in DS.