When it time to stop tracking tires.

[sachmo133]

thinking differently than tread wear. How many heat cycles are too much for PS4s tires? Thinking a cycle to be a 20 minute HPDE session.

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[Dana Pants]

A cycle is a day, not a session. It’s takes about 24 hours for the rubber to rearrange after cooling.

that being said, you can get rid of the tires when they no longer deliver what you ask of them or when they go bald.

I have had tires give up recently after 115 autocross runs (yokos) and 170 autocross runs(Bridgestones). Which translates to 6 days (rip) or 8 days (also RIP) at almost 20 runs/day. (Dual driven)

I sold my PS4s at near full tread depth because they delivered what I asked from them zero days.

 

[sachmo133]

A cycle is a day, not a session. It’s takes about 24 hours for the rubber to rearrange after cooling.

that being said, you can get rid of the tires when they no longer deliver what you ask of them or when they go bald.

I have had tires give up recently after 115 autocross runs (yokos) and 170 autocross runs(Bridgestones). Which translates to 6 days (rip) or 8 days (also RIP) at almost 20 runs/day. (Dual driven)

I sold my PS4s at near full tread depth because they delivered what I asked from them zero days.

I'm in the learning phase of this and that is why I'm asking about a specific tire. While PS4s are not racing tires not many are saying they are not good track tires.

 

[NightmareMoon]

You only need to toss them when they're showing cords, or if they're showing abnormal wear like chunking.

If you're paying $500 a day for an HPDE, you might want to take a guess if they'll survive the event and you may replace them with new tires sooner, so you don't waste your time and entry fee by running out of tire in the middle of the event.

MP4S are generally pretty hard wearing, so they'll last a while, but like most tires, if you don't have adequate camber and run them very very hard on track, you can overheat and chunk the shoulders early in their life, esp if they're nearly new. Well heat cycled MP4S are less likely to chunk when abused. Just inspect them between sessions (inside and out) and if defects show up, ask someone experienced or call it early for safety.

For autocross (competition) I nearly always replace tires when I feel the performance is falling off too badly. For street, I'll run them to the cords or wear bars, whichever they hit first.

 

[sachmo133]

You only need to toss them when they're showing cords, or if they're showing abnormal wear like chunking.

If you're paying $500 a day for an HPDE, you might want to take a guess if they'll survive the event and you may replace them with new tires sooner, so you don't waste your time and entry fee by running out of tire in the middle of the event.

MP4S are generally pretty hard wearing, so they'll last a while, but like most tires, if you don't have adequate camber and run them very very hard on track, you can overheat and chunk the shoulders early in their life, esp if they're nearly new. Well heat cycled MP4S are less likely to chunk when abused. Just inspect them between sessions (inside and out) and if defects show up, ask someone experienced or call it early for safety.

For autocross (competition) I nearly always replace tires when I feel the performance is falling off too badly. For street, I'll run them to the cords or wear bars, whichever they hit first.

Thanks for that info. Very helpful. I'm trying to find a balance. My yearly goal about 10 track days a year and the car is my daily driver but I don't drive a lot. I work from home. Seems like I'm going to get about 8K miles in just under 2 years. The other thing I wonder about is if it is worth going to a track alignment in the spring and then back to street in the fall after my last track day. I used the Ford track alignment spec for this season. Before the start of next year I'm going to get a set of track wheels that are squared but probably stay with the PS4s and then get A/S for the stock rims. I tend to overthink everything.

 

[NightmareMoon]

Thanks for that info. Very helpful. I'm trying to find a balance. My yearly goal about 10 track days a year and the car is my daily driver but I don't drive a lot. I work from home. Seems like I'm going to get about 8K miles in just under 2 years. The other thing I wonder about is if it is worth going to a track alignment in the spring and then back to street in the fall after my last track day. I used the Ford track alignment spec for this season. Before the start of next year I'm going to get a set of track wheels that are squared but probably stay with the PS4s and then get A/S for the stock rims. I tend to overthink everything.

I mean, there isn't much of a downside to running the track alignment year round. As long as your toe is good, your tire wear will be fine on the street. Sure, you can realign the car. Its just money.

For a dedicated track tire, look elsewhere than the MP4S. Its a fantastic compromise street performance tire, but its advantages are few if you just want to use it on track. You can get similar track performance for cheaper or more track performance for the same money. It IS a good idea to run a dedicated set for track days and a dedicated set for street.

 

[Egparson202]

A cycle is a day, not a session. It’s takes about 24 hours for the rubber to rearrange after cooling.

that being said, you can get rid of the tires when they no longer deliver what you ask of them or when they go bald.

I have had tires give up recently after 115 autocross runs (yokos) and 170 autocross runs(Bridgestones). Which translates to 6 days (rip) or 8 days (also RIP) at almost 20 runs/day. (Dual driven)

I sold my PS4s at near full tread depth because they delivered what I asked from them zero days.

@Dana Pants - I agree completely with your philosophy on replacement timing. If the tires are still meeting my performance expectations, I’ll run them til the cords show. If not, track time is precious and safety is paramount. Replace them if they’re not doing the job.

I do have one question though. Does your assertion that a heat cycle equals a day apply for road course sessions or autocross runs. I had always equated a 20-30 minute session with a heat cycle.

 

[Egparson202]

I mean, there isn't much of a downside to running the track alignment year round. As long as your toe is good, your tire wear will be fine on the street. Sure, you can realign the car. Its just money.

For a dedicated track tire, look elsewhere than the MP4S. Its a fantastic compromise street performance tire, but its advantages are few if you just want to use it on track. You can get similar track performance for cheaper or more track performance for the same money. It IS a good idea to run a dedicated set for track days and a dedicated set for street.

Solid advice.

 

[NightmareMoon]

If somebody has *data* on what counts for a heat cycle, I’d love to see it.

If I had to guess, I’d guess that the amount of “heat cycling” is proportional to the amount of cooling after being hot, and that some decent heat cycling happens between track sessions, even if the temperatures don’t entirely stabilize inside the tire in that period.

Anyway its acedemic since nobody is going to change their usage patrern much no matter how heat cyling works at the molecular level. And the standards for when a tire is heat cycled out is quite subjective.

 

[sachmo133]

I mean, there isn't much of a downside to running the track alignment year round. As long as your toe is good, your tire wear will be fine on the street. Sure, you can realign the car. Its just money.

For a dedicated track tire, look elsewhere than the MP4S. Its a fantastic compromise street performance tire, but its advantages are few if you just want to use it on track. You can get similar track performance for cheaper or more track performance for the same money. It IS a good idea to run a dedicated set for track days and a dedicated set for street.

Thanks for the advice. My main thing for a track tire is it needs to be drivable in the rain. Both to the track and on the track. Do you have a recommendation. Not looking for the fastest tire just a good balance.

 

[NightmareMoon]

Thanks for the advice. My main thing for a track tire is it needs to be drivable in the rain. Both to the track and on the track. Do you have a recommendation. Not looking for the fastest tire just a good balance.

That's good to know. MP4S does do well in the rain. Not sure what others to point you at. Yokohama A052 has a great reputation in the wet, and I think the RE71RS is good too?

 

[IanKar]

If it helps, the Ford Performance School at Charlotte use PS4S tires unless you upgrade to the Cup 2's. But if it rains, they stick to the PS4S. I asked what their lap time difference was between Cup 2's and PS4S in the dry, full course. 2 secs slower in the PS4S.

 

[sachmo133]

If it helps, the Ford Performance School at Charlotte use PS4S tires unless you upgrade to the Cup 2's. But if it rains, they stick to the PS4S. I asked what their lap time difference was between Cup 2's and PS4S in the dry, full course. 2 secs slower in the PS4S.

I'm surprised it is only 2 seconds. But I would gladly give up the 2 secs for the longevity and to be able to use it in the rain. My main concern is getting better between my sessions and events. Faster times are part of it but I also want to be consistent in line and braking too. I will never have enough days on track to jump from one tire to another so I have to try to piece together advice. I want to be smart with my money, for me, each weekend is between $1200-1500 (I always get the insurance and that ain't cheap on a $60K car) so I want to get the most out of it. I love the researching, planning, and doing of this. I really appreciate everyones take on it.

 

[kz]

thinking differently than tread wear. How many heat cycles are too much for PS4s tires? Thinking a cycle to be a 20 minute HPDE session.

Others already said it but you shouldn't worry about heat cycles at all - just the tread condition. They're not going to explode from too many heat cycles, just get slower- which in track days doesn't really matter that much.
And I'd suspect that PS4S doesn't really heat cycle out ever. It's very much a street tire.

 

[Egparson202]

PS4 for the win. There are other good choices. But better choices? Maybe not.

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