Street-tire class tires, stickiness & usefull life Options

[airsix]

For a couple of years I've been autocrossing in street-tire class with my 1.7 and I've always done ok - no wins, but no embarasments either. Until now...

This is my third year running these Dunlop SP8000 Sports - sizes 225/55-16 and 245/45-16 on 7" and 8" wheels. I know the tires are a little too wide for the wheels, but I bought them off a 944 and they came that way. I've just been using them up. I also know that this is an awful lot of rubber for a 1.7 - well I fully expected to have a fire-breathing six by now but you know what they say about best laid plans (let alone mine).

So there's the background. I've been running these tires for three years and they are close to being used up but they are not quite on the wear-bars yet. But... Either I don't drive like I used to, or these things just don't stick any more because I can't keep the car planted. I spun three times at the last autocross and I normally spin maybe once a year.

So my question: Do street tires "go away" just like race rubber after too many cycles? I don't want to blame the tires if it's me or something else wrong with the setup, but I'm trying to look for the most likely cause. Of late I have found that I can't even moderately trail-brake without losing the back-end. When I say loosing I don't mean it wiggles. I mean it's greasy.

Your musings will be considered and appreciated (even if the answer is "No man, tires are fine, you just suck"). (IMG:style_emoticons/default/laugh.gif)

-Ben M.

[Joseph Mills]

In the old days of yore, waaay back there (IMG:style_emoticons/default/biggrin.gif) your most effective AX street tire was either shaved, or worn to it's final 1/16th inch. There was no tread left to flex and two seasons was not long enough to effect the compound.

But modern compounds and tread design changed all this. It certainly has with AX specific tires.

Have you made any other changes to your suspension? Could toe-in, front or rear have been accidently altered? Front/rear brake balance working properly? Are you keeping a close eye on tire pressures? Just thinking outloud.(IMG:style_emoticons/default/unsure.gif)

You may have to adjust your driving style a bit to suit the autumn/twilight season of your tires.

If you decide to get some new ones, a friend also runs the Azenis and they are big bang for the buck. You could "downgrade" your wheel size at this time to a size that would have better synthesis with your 1.7 and have enough profit to pay for a new set of tires. And you will probably post quicker times. But then, the six dream would be over. (IMG:style_emoticons/default/w00t.gif)