Would you say these tires are still good for a track session?

[jmn444]

What makes those tires a risk for delamination?

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[Tomster]

Rear looks good. Fronts might not last the day. How many heat cycles?.

I disagree.

Those look like normal use cup 2s. He could even use a little more negative camber. Again, it all depends on the track

 

[Tomster]

This is the pyrometer I use.

 

[Tomster]

What makes those tires a risk for delamination?

Who? Me?

Delamination is more of a function of tire pressure and temperature (as well as overall tire condition). Too low a tire pressure is usually the cause of a delamination. That is why you have a warmup lap to get your pressures up.

The tires in question are fine. Again, me personally, I choose to start with a new set of fresh tires on a high speed track.

 

[jmn444]

Who? Me?

Delamination is more of a function of tire pressure and temperature (as well as overall tire condition). Too low a tire pressure is usually the cause of a delamination. That is why you have a warmup lap to get your pressures up.

The tires in question are fine. Again, me personally, I choose to start with a new set of fresh tires on a high speed track.

Ok good, thought you were saying there was an issue. They look fine to me as well. Just making sure I wasn't missing something I should be looking for on my own tires.

 

[Tomster]

Ok good, thought you were saying there was an issue. They look fine to me as well. Just making sure I wasn't missing something I should be looking for on my own tires.

I'm quoting you, but I know that you know this stuff.....

Every track has its own optimum alignment and pressures. The Ford Performance recommended settings are just a start. Using tire temps, handling, track characteristics, all bring together the optimum alignment and pressures for whatever track you are running.

Michelin put out a pretty good document. I was turned on to this by the michelin engineers who developed the cup 2s. They apologized for the dated document, but the info is good.

Another great resource was published by Billy Johnson. Let me see if i can find that article..... really great stuff.

 

[Tomster]

Here you all go. Really good reading.

https://motoiq.com/not-all-michelin-cup-2-tires-are-created-the-same/

 

[Narwaniec594]

They got one more day and then inspect again . Looks like they wear fine. What tire pressure you start with?

 

[jmn444]

Given the sunk cost of track days/weekends, it's definitely a good investment to have a 2nd set of wheels and tires to take with you just like extra brake pads and whatever other spares you think you need for a given car... allows you to inspect and replace after each session and not lose half a day or whatever if things don't last as long as you plan for. IMO it works out better long term to be able to squeeze that extra life out of expensive tires or drive pads down to 2mm or whatever without as much worry.

I saw blisters/peeling/delamination starting on my re71r's between sessions this summer and had plenty of time to swap to the super sports I had brought with in case it was rainy. Hell, even a brand new tire can get damaged going over a curb or hitting something that fell off someones car and cut your track time short.

Guess I just wanted to say all that because I DO think being safe is most important for all involved, but I'm also thrifty about not wanting to waste consumables

 

[firestarter2]

I disagree.

Those look like normal use cup 2s. He could even use a little more negative camber. Again, it all depends on the track

Yeah but running out of tires midday is a giant waste of money. Id bring 2 new tires for the front if you have them. Its saved my day before. My cup2 have usually heat cycled out before they corded.

 

[Tomster]

Yeah but running out of tires midday is a giant waste of money. Id bring 2 new tires for the front if you have them. Its saved my day before. My cup2 have usually heat cycled out before they corded.

Thats why I have another set of wheels with tires for that reason. I also i bring extra rotors and pads.

 

[torque124]

They got one more day and then inspect again . Looks like they wear fine. What tire pressure you start with?

I start with 28 as per the manual, and then adjust after each run as needed. I had to drop some more after the first run as it went up over 36 when hot, but I try to keep them around 35-36 when hot..
They are the stock sport cup 2's that came with the car in 2016, and have about 5000 miles on them, 4 track days and an autocross event.

I also do think they could do another track day.. Looks like the fronts will give up sooner, which is normal. What do you guys do in that case, just buy 2 new fronts and run the older rears, or just replace all 4 and ditch the rears as they are...

Thanks

 

[torque124]

Rear looks good. Fronts might not last the day. How many heat cycles?.

I am not sure, how do you count "heat cycles" ? I have 4 track days on them and 1 Autocross event, and 5000 total miles or so... They still stick on the track pretty well, I am not a very aggressive driver... Thursday I did New Hampshire Motorsports park with SCCA (track night in America) which is a very technical track, a lot of low speed chicanes, and off camber up and down the hill turns...

If a heat cycle is a track run, they have no more than 20, tops...

Thanks

 

[oldbmwfan]

I think the rears definitely have another day in them, or more, and they are wearing nicely. Hard to tell from the pics, but the fronts look like they might be getting close to cord. I would run them but just check each session. I'll bet you could coax another day or two out. My fronts have worn a bit more evenly than those (-2.3* camber, CF wheels), but that could be down to driving style also.

FWIW, my experience on the Cup2 for HPDE use is that they slow down about 1 second a lap after a couple heat cycles, then they just settle in around that level until they cord. They didn't progressively slow down more and more through their life. If you're not competing, no point in spending money for fresh tires unless, as Tomster said, you're at a track with particularly high loads liked banked, high-speed corners.

 

[torque124]

toe plates and camber/caster gauge... only part that's iffy is the thrust as I haven't strung it to verify rear is in line with front but it drives awesome.

I think the rears definitely have another day in them, or more, and they are wearing nicely. Hard to tell from the pics, but the fronts look like they might be getting close to cord. I would run them but just check each session. I'll bet you could coax another day or two out. My fronts have worn a bit more evenly than those (-2.3* camber, CF wheels), but that could be down to driving style also.

FWIW, my experience on the Cup2 for HPDE use is that they slow down about 1 second a lap after a couple heat cycles, then they just settle in around that level until they cord. They didn't progressively slow down more and more through their life. If you're not competing, no point in spending money for fresh tires unless, as Tomster said, you're at a track with particularly high loads liked banked, high-speed corners.

Thanks, and yes; those are the CF stock wheels that came with the car, with stock original tires...

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