I used the factory tires at my 1st HPDE. Any idea why the rears would be chewed up in this manner? I was wonderring if it was a defect or a problem with my suspension or just a rookie driver not knowing how to drive.




Here is the 2nd picture

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two more questions how do you get pictures to load automatically??? And for whatever reason i can't get my profile picture to show up

 

You are half way to getting the pictures to load automatically. All you have to do is copy the direct link for the picture from the photobucket site into the forum picture window. You get to that window by clicking on the yellow box with a small image of a mountain in it that is at the top of the forum post box. Like this:






I had some issues getting my profile picture to show up and I know one of the steps to resolving the problem was to have it posted in the My Garage section before I could get it to take.

Bill

 

Got the pictures to post. Any ideas why this happened tot he tires?????

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Here is your problem:

I used the factory tires at my 1st HPDE.

Hard tires will exhibit that tendency when driven at their limit at the track, particularly if the track needs a re-pave.

I doubt that there is anything wrong with the suspension, although you could probably adjust the alignment to get some negative camber.

Here is your dilemma:

If you are new to HPDE or track driving, the stock tires are actually very good from the standpoint that they will tell you when they are at their grip limit, giving you warning before you spin.

On the other hand, softer compound tires such as Toyo 888's, Hoosier R6 or A6, or Pirelli & Dunlop race slicks will give you grip like you won't believe but, they won't talk to you at all until they say bye-bye.

Tires, brake pads and rotors are CONSUMABLES, which means you will use them up when driving on the track at or near the cars limits.

If you want to continue to participate in track days, I would suggest that you buy a couple sets of used stock tires (generally easy to find on this forum) and run them while you continue to get seat time and improve your driving skills.

The tires will help you to stay within your limits and stay out of the wall. Driving your car at the limit is a blast. Crashing is no fun.

 

 

I've heard of occasional problems like that on the Z51 Supercar tires, and several on the Michelin PS2 ZP.

There seem to be lots of opinions on why it happens, but no one seems to have a real cure.

 

My take is this is called tire chunking. Many reasons not least of which is primarily/generally overheating the tire. Do a google on it, and just remember stock tires are very high perf for street useage; anything more under sustained race conditions and things can let go, slide, chunk, harden, etc.

You may also want to look at this thread in Autocross and esp. at post #4.

http://forums.corvetteforum.com/auto...per-stock.html

 

Good link so it seems to be pressure, over driving and tires related. Would you guys use these tires for another HPDE or just use them around town? I am asking if you think they are still good for 140 mph????

 

I have seen chunking like that but don't know the cause. What I find somewhat amazing is how good your tire looks besides the chunking. My tires after an HPDE look very blistered from one side to the other all the way around and lots of track pebble melted on the tire. So my next question is did you drive hard and if you did not why did the tire chunk.

 

On day one of the HPDE I did not drive hard at all. My top speed at VIR was about 110 in the strightaway and was just trying to learn the lines. On day 2, I was a bit more agressive almost lost it a couple times in the tight corners. My tires did have a lot of track pebbles melt in them so did the insides of the wheel wells. I drove from VA to RI about 600 miles after the event took the wheels, rotor and pads off and replaced them with my streets. I actually scrubbed the wheels with a nylon brush and then applied some Griots wheel reconditioner on them. I am trying to keep a set of wheel, tires, rotors and pads for track only and a set for cruising. So I am guessing you would think the tires are fine for another event?

 

If you plan on doing alot of track events, you will eventually want to get another set of wheels with dedicated track tires. If you get a set of 18" wheels all around, you will have more tire choices and can even get Grand Am scrubs for about $100 / tire. These are used tires from the Grand Am series, but with plenty of use left.

Many members actually tow a small trailer behind their cars to track events. The trailer carries the track tires and wheels and misc tools used during the day.

Other fools (like me) actually pull an enclosed trailer with the car inside.

Good-luck!

 

Bill-
Link doesn't work for me.
Jim

 

My left rear tire looks exactly like yours (I autocross frequently)...
I am eager to hear what others think about the integrity of the tire...
I don't want to replace just one tire if I don't have to...

 

I took my tires to Sullivan Tire yesterday and it was a rather humorous exchange. I have been going there for a long time and the older guy there we will call "Art" is pretty dry.

The conversation when like this:

Art - What the hell happened? I hear it called chunking. Art - Yeah it called chunking your not some damn kid, I also know you don't get that by driving like a normal human being. Me - Yeah, I was doing a buck forty braking hard taking the car near the limit on these junkie tires for a couple hours split up over as couple days. Art - looked at me long and hard shook his head an said: Your going to kill someone corvette or not this kind of driving isn't safe. I let it go on a few more second and said you crazy buzzard I did this on a race track. We Laughed and he said yeah these are street tires not really made to be driven that hard you should get some track tires. I explianed while I am learning to drive these let me know when I am approaching the tires limit and are perfect for now.

I asked him if he felt they were safe for another few sessions. He looked them over and said yes it is just cosmetic damage there is nithing affecting the intergity of the wheel. So that is one tire guys opionion anyone else dear to jump on this band wagon?

 

I know; and I just went looking for it via search and can't find it either. Strange. I'll keep looking.

 

turn off the AH

 

Good point with the AH. I did have it on the whole time. I will try it in comp mode next time do you think that will make a difference and not cause the chunking?

 

When I got my 08Z last year I purchased a set of wheels with OEM EMTs on them. The tires had 8K miles on them and I tracked and autocrossed them until the cords started showing. They also chunked like that. I didn't worry about it. Chunking may affect the tread to some degree but the tire is still safe as long as the underlying structure (cords, etc) isn't damaged.

Bill

 

Yep... that about sums it up.