jsaindc

I have Conti IIs on my 996 with about 2,000 miles and 4 autocrosses. Attended Potomac PCA autocross on Sunday and when I got home realized I took 2 huge chunks out of the left front tire on the outside tread (not the side wall). I have not been happy with these tires for autocross, they are ok for the street; however, I wanted to keep them for a little while since they are new.

Did the chunking come from incorrect tire pressure or just the fact that the lot was in terrible condition?

I also feel that I want to replace all 4 with something much better. Questions I have are the 3 tires worth anything and if I don’t get all new tires and just replace the bad one with a new Conti II will there be a problem in handeling giving there is 2,00 miles (heat cycled) on the other 3?

I appreciate your thoughts.

LVDell

Not properly heat cycled.

earlyapex

The front tires on Porsches last a long time. You can replace the chunked front tire and should feel no difference. Whether or not you buy 4 new tires only depends on your pocket book.

vove

I had an incident a while back where I had four new Mich. PSII's on and after a few thousand miles, the right rear went out. I had that one rear replaced and I dont notice the difference when driving. I don't think you will notice a difference if your other three tires are not too worn out.

But replacing all four will be the best route. To be sure, check with Paul at Radial Tires, he can also probably tell you why the tire chunked out on you.

Kerry

I suppose if the pavement was bad enough you could tear out pieces of tire, but the only time I've ever had anything close to this happen was with tires I had run under-inflated for the season wear so badly on the edges that small bits of the very thin layer of tire tread material (there was no 'tread' left) start to 'delaminated' for lack of a better word. Certainly not large hunks, though. I've driven a lot of autocross in three years, half of it on fairly rough concrete and I've never had chunking. I've occationally seen it in other auto-x cars but only with tires that shouldn't have been used for auto-x.

Don't know about heat-cycling. That's not something I've ever heard anyone in auto-x talk about, certainly not with street tires, which is all I've ever run. Yeah, I know, I'm strange.

With the chunking you've had, I'd sure like to get rid of the Conti's entirely. I've used Bridgestone S-03 (2 sets) Bridgestone S-02a (1 set) and Michelin Pilot Sport Rib (2 sets). The S-03s are a little less stickly than the other two.

LVDell

The heat cycling is VERY important in competition tires to prevent chunking, etc, but not as much with street tires. However, depending on what kind of temps the tires are generating you can suffer the same fate without a proper cycling of the tire. Just a good safe precuation. Since I do NOT do auto-x I cannot comment of the temps you might be generating in the tires.

Sids911

Check this post on renntech. My elder brother posted this when he was looking for replacement for his Boxster tires. Links to extensive tire reviews by various magazines, good read.

Hope that helps
Sid