A little background. I'm still fairly new to drivers ed events and was at my second event driving in white in the PCA DE at VIR last weekend. I purchased track wheels that the previous owner already had Hoosier R6 mounted with plenty of wear left that he had put 18 heat cycles into. Having talked to many about the difference going to tires such as Hoosiers I have been taking due caution while using them.

I put 3 cycles into them at CMP in September so going into the VIR weekend they had a total of 21 heat cycles. Prior to the weekend I inspected the tires and wheels and didn't there weren't any issues. At VIR I put 7 more heat cycles into them. As I was cleaning the wheels yesterday I noticed a split about 0.5" long at the base of the tread on one of the rear tires. I inspected the other 3 again and found that the other rear tire had a similar split. The front tires are fine. I was measuring 36-37 psi hot after each session.

Has anyone with experience using Hoosiers seen this before?
Tire is a Hoosier R6 295/30-18 Manufactured 5113 with 28 total heat cycles.




Hoosier R6 295/30-18 5113 manufacture 28 heat cycles

 

We saw this late last year on a R6 with 12 heat cycles. That tire is toast. We hope to have better luck with the R7's

 

36-37 is high. Some people say that Hoosiers should be run with a high pressure but I find 30-32 range is better.

What kind of car are you driving?

Lastly, 28 heat cycles is plenty! How many were you hoping for?

 

Wow - you are smart and lucky to have caught them. I'm surprised they had not corded long ago.
I get 16 heat cycles on mine (both R6 and R7).
I wonder if they had fewer cycles than you were told.

 

Thanks Don. Yep, that's it for this set. The other rear tire is exactly the same. Kind of odd as it happened on the inner side of both rear tires.

Driving a 996C2. Looking at the tires, I agree that I could be running lower pressures. Still figuring all of this out. Was only thinking of 30 cycles based on what I had heard from a couple others. That said, I was just planning to use them up and put NT-01 or R888 on as I am learning. Right now am planning on R888 as the NT-01 doesn't come in the right size for the rear.

Thanks Rick. I'm pretty confident in the # of cycles as they were marked on the sidewall and I'm definitely not at their limit at this point. Just curious, when you say you get 16 heat cycles on yours, is that when the wear marks are showing the tread is used up (or cording) or are you feeling the performance of the tire degrading to a point where you need the new tires?

Interesting note: I am beginning to realize that the consumption of consumable parts is increasing as my lap times are decreasing. I went through my last set of brake pads (stock mind you) much faster than the previous set. But the last weekend at VIR track I was 7-10 mph faster on the back straight than a year ago. That's A LOT more energy into the brakes.

 

CMP kills tires. You could have gotten some more HC's out of them if not for CMP but 28 is plenty. Pressures are a little on the high side but still within range. How much camber are you running?

 

Bingo!

 

I see those splits all the time as I run pretty much only Hoosiers. You will either see that split or the cords, or both, it depends on how the tire was stored/driven.

#1 There is no such thing as 18 heat cycles and plenty of life left in a Hoosier. If you consider plenty of life to be several more than 10 more heat cycles unless you are running auto x.
#2 The purchase date is important to know as age can be a factor
#3 The storage climate is also important
#4 The speed, duration and surface the previous driver drove them on is all important information
#5 CMP is horrific on tires. 2 days at CMP is 4 days at most other tracks.

 

These tires are 2 years old! I also think that 28 HCs must some sort of record for heat cycles on a Hoosier tire.

 

Yeah, CMP tears up tires. Running -3deg Front -2deg Rear.

Thanks. So on #1 is that based on wear or feeling of traction? Since I started at 18 HC my perception of traction with them would be completely different than starting with a new tire. Was still A LOT stickier than I was used to. My statement on plenty of wear was only based on the depth of the wear indicators. Understand re 2-4, don't know when they were purchased or how they were stored before me, though the manf. data was 51 week of 2013. Once I got them they were stored inside my insulated garage. Pretty sure PO drove only at VIR in the same type of car. Totally agree about CMP, enjoy driving the track, but don't really like it because it is so rough.

 

This used to happen frequently to us when I ran Hoosiers on my 996 race car. It normally occurred after 8 - 10 heat cycles, but sometimes less.

Scariest was coming out of the infield and onto the tri-oval at Pocono. It failed at about 110 mph.

I refuse to use them anymore.

 

"Thanks Rick. I'm pretty confident in the # of cycles as they were marked on the sidewall and I'm definitely not at their limit at this point. Just curious, when you say you get 16 heat cycles on yours, is that when the wear marks are showing the tread is used up (or cording) or are you feeling the performance of the tire degrading to a point where you need the new tires?"
Hi Trojan
I would get first sign of cording right at 16 heat cycles; they would have lost ultimate grip well before then, but still useful.
Earlier this year I had my first sign of sidewall splitting - this was on the 13th cycle, no cording, no sign of failure.
How did I find out? Exiting the Toe of the Boot at Watkins Glen, when the left rear tire deflated. My first ever crash. I was fine, car is as good as new, track insurance did what it was supposed to do. But I was still pissed off.
First time I ever saw a split, too. I suspect but can't prove that the tires, which were leftovers from my previous season, were damaged by sitting on the car (with the weight of the car on it) in my insulated but not really heated garage for longer than I had planned. I had a failed Schrader valve on a rear tire. I didn't mark the tire as suspect after replacing the valve, so I can't be sure it was that tire. But there's at least a 50% chance it was.
What I learned - pay a lot more attention to my tires, especially inside sidewalls, and get the tires out of the cool garage sooner.

 

On #1 Not really if they weren't over driven. They could still have some grip left (especially if you are used to a street tire). They usually only turn super slick if you drive them for really long sessions or overdrive them (like lots of sliding and correcting). I have bought used ones when trying to see if certain sizes would fit on my car. I had some that didn't look that great but lasted 6-7 more HC, and then some that looked like they would last forever and corded in 2 sessions. It's all down to how the tire was driven, maintained (temps and pressures) and stored over the winter.

I would say those R6's more than held up for the driving you gave them, especially with any days at CMP. lol. People have corded R6's in a day or two there.


One thing you should check though also is toe and camber. If you somehow still have a lot of tread depth left and that is happening, you may want to take a pyrometer to the tire and make sure you aren't superheating the inside edge. That would be the only thing left to check.

 

"Driving a 996C2. Looking at the tires, I agree that I could be running lower pressures. Still figuring all of this out. Was only thinking of 30 cycles based on what I had heard from a couple others. That said, I was just planning to use them up and put NT-01 or R888 on as I am learning. Right now am planning on R888 as the NT-01 doesn't come in the right size for the rear."

I drive a 996 C2 as well - and I've driven R888s and NT-01s back to back. What size rear are you looking for (I use a 315/18)? Because while the R888s are ok for the front, the rear 888s really suffer from chucking and lack of grip. Driving back to back, I've found the NT-01s to be far superior on the rear.

 

These guys are spot on:
CMP is the worst on tires...although I love the technical aspects of the track.
Very surprised you got that much out of them.
I get one good race out of a Hoosier there. 2nd race I'm sliding all over the place. Mine cycle out much sooner than they wear out.
I am experimenting more with the R7 and breaking them in slowly. Seemed to work pretty well last race.