A recent batch of R7's for a friend with a 800hp r7 and a Porsche Cayman GT4 had a strange tire failure on both cars.

this was on the M3...



And these on the GT4....


This happend on the 2nd track day and both cars are about 1600kg. He says they were at 30psi hot. Any ideas?? Have not seen this before.

That first tyre is sponsored by Monster Energy. Damn that's wild.

Its one of those new fangled turbo M3 cars so it must crazy monster torque

I'm going to throw out an educated guess and say its a compound/process problem. Look closely into the tears and you can see strands between the edges of the tear.
"Plastic deformation is the permanent, non-reversible change in shape or size of a solid material that occurs when it is subjected to stresses exceeding its yield strength. Unlike elastic deformation, which is temporary, plastic deformation involves atoms slipping past each other or permanent shifts in the crystal structure, meaning the material does not return to its original form once the load is removed."
I'm sure a materials scientist would be able to compare 2 samples and see what was different. Hopefully its just a bad batch and not a new compound fault.

Yup that more or less what I thought as well. They look like shear tears. These were R7's from a batch a few months ago.

@blacksheep-1 any insights??

No idea what happened (but that one tire looks to be dated 2023?) but you shouldn't have to worry about an R7 batch problem since the R8 is a thing now...er....trackattackpro or whatever they call it.

Looks like he spun the tire under load, across the elephant turds that line the track edge.

blacksheep-1 said:

elephant turds that line the track edge.

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Is that the official term designated by the series? I really want to hear the commentators use it.

DaveW said:

No idea what happened (but that one tire looks to be dated 2023?) but you shouldn't have to worry about an R7 batch problem since the R8 is a thing now...er....trackattackpro or whatever they call it.

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All the R7 tires at Tire Rack are marked for clearance. Hoosier is no longer making the R7.

Like BS1 I think it was caused by damage and surprised as a Florida boy he did not call them " Gator's Teeth " like some of us do up North, ha. Er, some do call them " Cow Pie Curbing " but that could be a Texas thing?

Do they have gator's teeth, cow pies, or elephant turds at his local track in Santiago, Chile?

Nope. no gators here!! Cougers maybe, but the real wild ones... I mean the ones with four paws and whiskers.. Not the other ones, they do a different kind of damage. Should have said Pumas to avoid the confusion!

Are they going to send the photos to Hoosier?

Those are expensive track tires.

Yup, am sending them to Hoosier tomorrow. Will update. Was trying to get the dates on the tires sorted out. As mentioned, one is from Jan 2023...

Mad Hatter said:

A recent batch of R7's for a friend with a 800hp r7 and a Porsche Cayman GT4 had a strange tire failure on both cars.

this was on the M3...

View attachment 110150

And these on the GT4....
View attachment 110151

This happend on the 2nd track day and both cars are about 1600kg. He says they were at 30psi hot. Any ideas?? Have not seen this before.

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Are these the tires you normally run? It looks like both are a combination of not enough negative camber and too much understeer. The wear has a regularity to the pattern. It's not just pick-up. It looks like in both scenarios you have a driver who cranks in a ton of steering while still hard on the brakes.

I have never run these tires, but 30 psi would be on the high side for me.

TeeLew said:

It looks like in both scenarios you have a driver who cranks in a ton of steering while still hard on the brakes.

I have never run these tires, but 30 psi would be on the high side for me.

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Sadly this is exactly how you drive this new M3's fast on track since they are AWD the understeer in corners is a natural characteristic.

bnight said:

Sadly this is exactly how you drive this new M3's fast on track since they are AWD the understeer in corners is a natural characteristic.

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Well, that kinda stinks...

This is for another fellows car.. He is mostly in time trials and have not seen him race. For my boss, I found the sweet spot for tire wear vs performance was 32 front/30 rear. But AWD and loads of torque is going to be a different animal.

Mad Hatter said:

For my boss, I found the sweet spot for tire wear vs performance was 32 front/30 rear.

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Which tires?