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Discussion Starter #1
Hello!

Can anyone tell me why my front driver's side tyre is getting ruined at track day? Two different tracks (Lime Rock & NY Safety Track) and 2 different tyres (GoodYear Eagle F1 & Michelin Pilot 4S). Both same result and I thought 4S would hold up better but got chewed up in 1 day.

2017 718 Cayman S
 

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That's an awful lot of wear for one day at the track. Exactly why I don't track my Porsche's. Hard to understand how so much damage can be done in one day. Hope you figure it out before you go broke buying new tires.
 

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Wrong tires for as fast as you are driving. Also not enough negative camber in your current alignment.

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Discussion Starter #5
Thanks. It's either I buy new tires or pay for speeding tickets :)
That's an awful lot of wear for one day at the track. Exactly why I don't track my Porsche's. Hard to understand how so much damage can be done in one day. Hope you figure it out before you go broke buying new tires.
 

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Not enough negative camber. (I should know - now waiting for Cup 2s after barely getting in two track days.) When you get replacements, get an alignment and ask for as much negative camber as they can dial in. If you have the Benjies, have camber plates installed. They may also shave up to 2 seconds from your lap times. The P4S's are perfectly fine and a good, all-around tire. I liked them, but I upgraded to Cup 2s: Incredible grip; don't last long (see parenthetical statement on line one;) and they might cause a little rubbing in parking lots and such where you really turn the front wheels.

That said, insufficient negative camber is probably not the only cause. Check your tire pressure cold, when arriving at the track and when you come off after your first session. Post them here and people more knowledgeable than me can comment. Note: I spent some time chasing the perfect pressure and drove myself nuts adding air, bleeding air, adding air, etc. I gave up and just drove, but your problem may force you to do that WITH A GOOD GAUGE.

Lastly, which directions (clockwise or counterclockwise) do the tracks run, and how may turns are in each? You might also describe how aggressive you are, how often you do track days, and what level you are.

I look forward to seeing any new posts and hope to learn something myself.
 

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Discussion Starter #8
Underinflation of both tires.
Thanks and I hope that's the case since it's an easy fix. Now with some more detail, stock GoodYears lasted my first 4 track sessions (NJMS, Poconos, Limerock, NJMS) starting with stock 33psi at cold. Then I got Ohlins suspension and stock realignment went to lime rock and lowered my tire pressure from 33 stock cold to 30. By 3rd run tire was done. I then switched to 4 michelin 4s and got an aggressive alignment about -2.5 front and -1.5 rear and went to NYST for the first time. Did 3 runs no problem then an instructor suggested I lower my tire pressure since I was already at 41. Went down about 4 psi and did 2 more sessions and noticed the same thing. So it was never below 30 before running and why is it only happening at my front driver's side at 2 different tracks? Also, could stiffer suspension require higher tire pressure? Is it a cayman thing?
 

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Discussion Starter #9
Not enough negative camber. (I should know - now waiting for Cup 2s after barely getting in two track days.) When you get replacements, get an alignment and ask for as much negative camber as they can dial in. If you have the Benjies, have camber plates installed. They may also shave up to 2 seconds from your lap times. The P4S's are perfectly fine and a good, all-around tire. I liked them, but I upgraded to Cup 2s: Incredible grip; don't last long (see parenthetical statement on line one;) and they might cause a little rubbing in parking lots and such where you really turn the front wheels.

That said, insufficient negative camber is probably not the only cause. Check your tire pressure cold, when arriving at the track and when you come off after your first session. Post them here and people more knowledgeable than me can comment. Note: I spent some time chasing the perfect pressure and drove myself nuts adding air, bleeding air, adding air, etc. I gave up and just drove, but your problem may force you to do that WITH A GOOD GAUGE.

Lastly, which directions (clockwise or counterclockwise) do the tracks run, and how may turns are in each? You might also describe how aggressive you are, how often you do track days, and what level you are.

I look forward to seeing any new posts and hope to learn something myself.
See my previous reply for some more detail. So it shouldn't be camber and I don't think it's suspension because the car feels great and am running great times. While lime rock is 90% right turns, NYST Uptown is about 70% left turns so the wear should not be on the same location and that's what's bugging me. My 1st attempt in solving this is to increase tire pressure to stock and leave it at that for entire day. My tire installer is blaming the tires and says no street tires will last for track and I'm not really buying that just yet based on reviews I've seen out there. I really don't want to get into having 2 sets of tires to switch back and forth.
 

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Discussion Starter #10
Wrong tires for as fast as you are driving. Also not enough negative camber in your current alignment.

Sent from my SM-N950U using Tapatalk
One of the NASA instructors has a Carrera 4S with street pirellis and seems to be doing fine. I imagine he's also a faster driver than me. Temperature was about 70. I'm not ruling out your reasons but I don't understand why suddenly it's happening in one day and only in 1 location
 

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This is definitely not a “Cayman thing”. Most likely something is off with the suspension and/or allignment after Ohlins installation. Get a good mechanic to check all suspension components and redo alignment.
 

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See my previous reply for some more detail. So it shouldn't be camber and I don't think it's suspension because the car feels great and am running great times. While lime rock is 90% right turns, NYST Uptown is about 70% left turns so the wear should not be on the same location and that's what's bugging me. My 1st attempt in solving this is to increase tire pressure to stock and leave it at that for entire day. My tire installer is blaming the tires and says no street tires will last for track and I'm not really buying that just yet based on reviews I've seen out there. I really don't want to get into having 2 sets of tires to switch back and forth.
In fact, everything you are saying is pointing towards something anomalous. My car is dead stock and on stock Pirellis and nothing like that happens. What is weird is that the damage shown I saw in two cases (not on my cars) : using all season tires that cannot stand the heat (not your case but it does look like heat damage) or blasting autocross full tilt on cold tire (not your case). I run 28-29 psi cold, no more than 36-38 psi hot. So it is very, very strange to have heat damage when you "underinflate" to 30 psi - although it makes perfect sense that underinflated tire will generate a lot of heat. Did you ever check whatever instrument you are using for tire pressure against some known-to-be-correct instrument? For example, I had my tire pressure gauge checked by Bridgestone guys that were on the track when they were presenting then new RE-71 R tire and I know it reads 0.3 psi low. All of that would not explain why it happens only on driver's side - unless you are using car's TPM to read the pressure and that one (front left) is defective and reads WAY too high. So, you might have 24 psi while it reads 30 psi (for example).

Just guessing how it would be possible ... Good luck with solving it. Something is definitely not right, I would certainly try to figure out what before buying set of front tires every two weekends.
 
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Sounds like your camber is ok, and pressures are within reasonable ranges (maybe a little high when hot). However, both pictures indicate heat damage to me.

I damaged my left front Goodyear the same way on the first autocross outing this year. This was on a training course with a two times around right hand skidpad. Cause? Not enough pressure nor camber.

Given everything posted so far it sounds like you're either pushing a little harder on right turns than the left front tire can handle, or like others have said, there is something anomalous in your suspension. I'd recommend checking your pressures right after a hot lap. Anything more than 36 psi is too much in the front. If your pre-lap pressures left and right match, and the post-lap pressures don't, you are either turning harder in one direction or something is off in your suspension. You should also check the tread temperatures (inside, middle, outside) with a pyrometer (sp?). That will tell you if there is an issue with alignment or pressure. What are your other alignment values?

If you can't figure out what's causing the heat, you only have a few of choices. 1) get smoother. 2) slow down. 3) get tires that can handle the heat. 4) ???

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Discussion Starter #14
I was using my own pressure gauge and verifying with TPM and both matched. In fact I just tried another pressure gauge and all are in sync. Even the alignment visibly looks like it has negative camber as it should. Took the wheel off today and inspected for any rubbing in the fender but all looks good. What I found was the damage to the circumference is not consistent. Half of the outer treads look fine. Again, it just leaves me wondering why that front right only even if it was low tire pressure.
In fact, everything you are saying is pointing towards something anomalous. My car is dead stock and on stock Pirellis and nothing like that happens. What is weird is that the damage shown I saw in two cases (not on my cars) : using all season tires that cannot stand the heat (not your case but it does look like heat damage) or blasting autocross full tilt on cold tire (not your case). I run 28-29 psi cold, no more than 36-38 psi hot. So it is very, very strange to have heat damage when you "underinflate" to 30 psi - although it makes perfect sense that underinflated tire will generate a lot of heat. Did you ever check whatever instrument you are using for tire pressure against some known-to-be-correct instrument? For example, I had my tire pressure gauge checked by Bridgestone guys that were on the track when they were presenting then new RE-71 R tire and I know it reads 0.3 psi low. All of that would not explain why it happens only on driver's side - unless you are using car's TPM to read the pressure and that one (front left) is defective and reads WAY too high. So, you might have 24 psi while it reads 30 psi (for example).

Just guessing how it would be possible ... Good luck with solving it. Something is definitely not right, I would certainly try to figure out what before buying set of front tires every two weekends.
 

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It's a pretty reputable shop known for bmws and they really take their time to do it right. When I go to get my new tire installed I will ask them to check it. Thanks.
This is definitely not a “Cayman thing”. Most likely something is off with the suspension and/or allignment after Ohlins installation. Get a good mechanic to check all suspension components and redo alignment.
 

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Hello!

Can anyone tell me why my front driver's side tyre is getting ruined at track day? Two different tracks (Lime Rock & NY Safety Track) and 2 different tyres (GoodYear Eagle F1 & Michelin Pilot 4S). Both same result and I thought 4S would hold up better but got chewed up in 1 day.

2017 718 Cayman S
Some additional photos showing inconsistency to the wear.
showtime83, Looks like you're pushing too hard on tires that haven't been shaved and/or heat cycled. It might help to change your line to use less steering angle i.e turn in a bit sooner, enter less aggressively and let the car roll through the apex... then get back on it ;-)
 

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Or, your left front thrust puck is shot, allowing your toe to change depending on braking and weight transfer. Tarett makes a solid Red thrust puck that will reduce to a minimum, forward and backwards movement of the front wheels and rear wheels reducing toe changes. Better yet, I recommend using Tarett Cup LCA's with the Ohlins, the reason is that by having less wheel rate due to less actual wt of the LCA, the Ohlins are more effective damping the springs/wheels/suspension. They are also much stiffer structurally than OEM LCA's and have a monoball inner and and a large outside bushing that really improve turnin, mid corner throttle response and trailbraking. They use the solid red thrust puck described above to prevent wheel movement and allow caster and wheelbase adjustments as well. The last part is a bonus, the camber adjuster is internal shims, up to 20 mm per wheel, which equate to -2.0 degree camber, without additional stress on your wheel bearings.
Your install shop should give you all of that 20 mm, then use the OEM camber adjuster to complete your alignment. I am using -2.7 f and -2.5 r with RE71R's 255/35/18f and 275/35/18r race tires on 9 inch forged monoblock f wheels and 10 inch in the rear. I also am using my OEM wheels for daily drives, Michelin 4S's 245/35/18 f and 275/35/18 r.
Lastly look into having your car corner balanced. Not sure how much you weight, but that is a factor in getting the weight distribution correct on our Caymans. I weight 200 lbs, so my shop added this weight to my seat, before corner balancing. My car actually sits higher on the drivers side without me in the car now.
Oh, by the way, I use 26 lbs f and 28 lbs r for autocrossing with my RE71R's and they do not look like your driver side shoulder. They are grained across the entire face of the tire, not on the shoulders, due to the camber.
 
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Discussion Starter #19
Thanks for the tips. It was a new track for me and at times I was braking a bit late so you may be onto something here but this time the track was mostly left turns but keeps happening on same location.
showtime83, Looks like you're pushing too hard on tires that haven't been shaved and/or heat cycled. It might help to change your line to use less steering angle i.e turn in a bit sooner, enter less aggressively and let the car roll through the apex... then get back on it ;-)
 

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Clearly overheating the shoulders due to several possible factors:
1. A glaring setup issue that was missed.
2. Driving technique causing the car to push excessively in the corners.
3. Tires that were not really designed for continuous lapping.

I typically get 5-6 track days on a set of RE-71r or 10-12 track days on a set of Hankook RS4. The tires wear very evenly with no signs of overheat and I typically run at the pointy end of the time sheet for street cars. My car has GT3 arms, 2.6 neg front camber, lowering springs on stock struts, and a pro corner balance and alignment from a well known race-prep shop with lots of podium clients. I run 35psi hot pressures on 18" OEM wheels.

If it were my car I would have a full corner balance and alignment done 1st, looking for any issues that might have been missed while changing suspension components. I would definitely get a 2nd set of wheels and tires just for track days because in the long run it will save you money. I would also get some coaching from a top local driver to see if there are any areas you need to clean up in your cornering technique. My first guess is coming into a corner too hot and pinching the exit with a lot of steering input under throttle. I have not seen a track video to confirm this but that is what the tires are suggesting.
 
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