S197 Boss Lite - 2011 Mustang GT Build Thread Profile - S197 Mustangs

[stevbd]

So much for my reading comprehension.

He did not have any problem when running the same tire as you.



I will try to gracefully bow out now . . .

Please don’t! You’re making a lot of good points and have me thinking.

One thing seems clear, my toe out is doing nothing good for this problem right? Clearly I need to set it to zero.

 

[Junkyard Dog]

@dave2278 is running the SC3, different tire. I’ve run that tire without this delamination problem.

stevebd, had I read more slowly and carefully, I would have noticed this before now. My apologies for wasting your time reading my posts. I have deleted all of my posts above, and I will try to be far more careful in the future.

 

[stevbd]

stevebd, had I read more slowly and carefully, I would have noticed this before now. My apologies for wasting your time reading my posts. I have deleted all of my posts above, and I will try to be far more careful in the future.

You shouldn’t delete anything. You’re on the right track and I think it’s a clue that I’ve run the SC3 in this same exact manner without problems but the 3R is delaminating on me.

 

[dave2278]

You shouldn’t delete anything. You’re on the right track and I think it’s a clue that I’ve run the SC3 in this same exact manner without problems but the 3R is delaminating on me.

I think you're on the right path all things considered.
A cold tire is definitely not as flexible are tearing makes sense to me. A soft tire that is not flexible I think is likely your problem.

 

[CarSalesman]

Reading your entire thread. You mentioned a 4 point harness and the Boss seats. I don’t see a harness bar. How are you mounting the shoulder straps?

 

[stevbd]

Reading your entire thread. You mentioned a 4 point harness and the Boss seats. I don’t see a harness bar. How are you mounting the shoulder straps?

I use the Scroth 4 point ASM harness. One of the shoulder straps clips into the rear seat belt receptacle on the inside of the rear seat, the other clips into a receptacle that you install on the outside of the rear seat.

 

[blacksheep-1]

For some reason,I'm just now seeing this. What you are looking at on the outside edge is the tire rolling over. That little gap is where the tread " band" is bonded to the carcass. Depending on who builds the tire, it is more prominent. The normal way to get around this with a band aid is to add more psi. This is one reason IMSA makes us run a minimum tire pressure at race start. The better fix is usually to add camber, check the toe and maybe add a little pressure. Take one of those butane torches with you, and a paint scraper so you can clean off a band of rubber at the wear indicators, that way you get a better defined idea of what's going on without the crap getting into the middle of it.

 

[steveespo]

I feel like the outer wear is normal but the delam is not?

How much use on the tire? What pressures cold/hot

 

[stevbd]

How much use on the tire? What pressures cold/hot

12 heat cycles, 700 miles, track only, 34-35 psi hot. I usually start at about 28 cold and bleed down to 34-35 hot.

 

[Junkyard Dog]

This is one reason IMSA makes us run a minimum tire pressure at race start

But that minimum is less than stevebd is starting with, isn't it?

 

[Dave_W]

@blacksheep-1 You mention cleaning the crap off the tire with a torch to check the wear indicators. Does that mean you think the frayed edge is OPR buildup? The OP thinks it's the shoulder tread delaminating. When I first looked at the photos, I thought it was OPR. From the tire temps, perhaps the middle & outside of the tire is not being worked hard enough to clean off the OPR, except for just the edge of the outside shoulder scrubbing it off from understeer and creating the frayed edge of OPR.

I marked up one of the pics. OPR, delamination, or both?

 

[Junkyard Dog]

12 heat cycles,

Are counting a heat cycle as a an HPDE day or as every 20-30 minute session out on track and then parking in the paddock to cool off? 12 heat cycles in 700 miles is 58 miles per heat cycle.

700 miles, track only, 34-35 psi hot. I usually start at about 28 cold and bleed down to 34-35 hot.

700 miles on track

How many miles on track should a 100 tread wear tire last on an S197 Mustang?

 

[stevbd]

@blacksheep-1 You mention cleaning the crap off the tire with a torch to check the wear indicators. Does that mean you think the frayed edge is OPR buildup? The OP thinks it's the shoulder tread delaminating. When I first looked at the photos, I thought it was OPR. From the tire temps, perhaps the middle & outside of the tire is not being worked hard enough to clean off the OPR, except for just the edge of the outside shoulder scrubbing it off from understeer and creating the frayed edge of OPR.

I marked up one of the pics. OPR, delamination, or both?
View attachment 112350

It might be hard to tell from the pics but the tires are unquestionably and completely delaminating and failing around the outside outer edge. The yellow part is the surface layer of the tire. None of that is OPR. The red section is the underlying structural carcass. This only happens using 3Rs. My other tires wear normally.

 

[stevbd]

Are counting a heat cycle as a an HPDE day or as every 20-30 minute session out on track and then parking in the paddock to cool off? 12 heat cycles in 700 miles is 58 miles per heat cycle.

700 miles on track

How many miles on track should a 100 tread wear tire last on an S197 Mustang?

These tires were run in a local format at Palmer that consists of four 1 hour and 15 minute sessions, two in the morning and two in the afternoon, separated by 30-45 minute breaks and a longer 2 hour break over the lunch hour. So I’m counting 4 heat cycles per day x. 3 days.

I think 700 track miles might be not be terrible, but it’s the delam I’m frustrated with. It’s happening on every single 3R I run, I really don’t think it’s a coincidence or one defective tire.

 

[blacksheep-1]

@blacksheep-1 You mention cleaning the crap off the tire with a torch to check the wear indicators. Does that mean you think the frayed edge is OPR buildup? The OP thinks it's the shoulder tread delaminating. When I first looked at the photos, I thought it was OPR. From the tire temps, perhaps the middle & outside of the tire is not being worked hard enough to clean off the OPR, except for just the edge of the outside shoulder scrubbing it off from understeer and creating the frayed edge of OPR.

I marked up one of the pics. OPR, delamination, or both?
View attachment 112350

I'm having a very difficult time " seeing" what is going on without a clean tire to look at, normally, I take a heat gun or torch, and scrape a clean path across the wear dots, or wear bars to get rid of the clutter. I'm a " race skick" guy, not a treaded tire guy, so I'm trying to work my way through the issue.

 

[blacksheep-1]

But that minimum is less than stevebd is starting with, isn't it?

Well slicks are totally different from treaded tires, this is what threw everyone a curve with the GTD tires the first year, they were slick, but acted like a treaded 200tdw tire. IMSA makes us start at 18.5 psi, which will shoot you right through the upper envelope of tire performance so there's all type of black art going on since we can't pre heat tires. Look up Mike Shank racing from a couple years ago at the 24, $100K fines, pulled credentials...probation, all about getting that minimum psi on a 30 degree day.
Also, don't put a huge amount of trust in across the board tire temps, I've said this before, using Temps to justify pressures works much better in an LMP, or open wheel car where the suspension movement is only about 2 inches, God bless Carroll, but he's an open wheel guy and didn't really explain that in his books, but production cars flop all over the place, a 75 degree swing is not such a big deal and the middle temp is always lower.
I just came from a track day at Daytona where 2 fairly new Corvettes whacked the wall at around 190 mph because of tire failures, probably totaled both, so I'm a bit leary of what I'm looking at on a treaded tire.

 

[Dave_W]

@stevbd Since this is a consistent issue with this one tire model, I think you're best bet would be to contact Goodyear support directly and work with them. You might even get them to comp you a tire. Please let us know what they say.

Contact Us

Contact Us

www.goodyear.com

 

[stevbd]

@stevbd Since this is a consistent issue with this one tire model, I think you're best bet would be to contact Goodyear support directly and work with them. You might even get them to comp you a tire. Please let us know what they say.

Contact Us

Contact Us

www.goodyear.com

@Dave_W good idea but I’m striking out with Goodyear. They don’t have any customer tech support line that I can access. They told me to talk to a local dealer. I’m not looking for any compensation from them as I think this is a user error problem not a tire defect problem. But I’m surprised that I can’t find any knowledgeable tire expert at a tire company.

I took my questions to Tire Rack and they were a bit better. The guy there thinks I have too much negative camber. He said cold shearing is definitely a thing. He wants the outside edge hotter and more even temps across the tire face. Pretty much what people are saying here. He thinks it’s more of an excessive camber problem than a toe out problem.

In the meantime 3Rs are on national back order, so it looks like I’m picking this back up next spring.

Thank you all.

 

[blacksheep-1]

These tires were run in a local format at Palmer that consists of four 1 hour and 15 minute sessions, two in the morning and two in the afternoon, separated by 30-45 minute breaks and a longer 2 hour break over the lunch hour. So I’m counting 4 heat cycles per day x. 3 days.

I think 700 track miles might be not be terrible, but it’s the delam I’m frustrated with. It’s happening on every single 3R I run, I really don’t think it’s a coincidence or one defective tire.

Well, we ran the 3s in a WRL event and they were rock solid, but as @Junkyard Dog stated, that's a ton of miles on a tire. Slick wise, we get a total of 50 minutes in a session, including in, out and pit lane laps, and we write the tires off after 1 session. If you stayed on the track for the total of 2, 1.5 hour sessions, those tires are dead in 1 day.

 

[stevbd]

Well, we ran the 3s in a WRL event and they were rock solid, but as @Junkyard Dog stated, that's a ton of miles on a tire. Slick wise, we get a total of 50 minutes in a session, including in, out and pit lane laps, and we write the tires off after 1 session. If you stayed on the track for the total of 2, 1.5 hour sessions, those tires are dead in 1 day.

You have a bigger tire budget than I do!