[Talx]

I have been encountering some unusual tire wear at the track. I’ll give a bit info on my setup. I’m driving an M2C with Ohlins R&T coil overs with 90 front and 140 rear springs, with baljoints on all suspension links, 2.7 camber in the front with 0.003 toe and 2 camber in the rear with 0.12 toe, tires are AR-1 all around 265/35/19 front and 275/35/19 rear with 5mm spacer up front on OE M2C wheels. At the track I’m running about 26 psi cold and around 35-37 psi hot all around.

Now in the rear it looks like I’m getting even Tire wear and I’m managing about 4-5 track days on each set which is worth about 75km of hard driving on every track day.

If you look at my front Tires the wear pattern isn’t what I would expect it to be and I feel I’m not getting the full potential out of the life of the tires. If you look on the inner edge of the inside tire I’m getting excessive wear and also towards the outer edge about 3/4 way across the width.

I have been talking to some people that are tracking with even 3 degrees of camber in the front and they tell me they have not been getting as much wear on the inside of the tire as I am with less camber and are getting consistent wear pattern across the width of the tire.

Anyone have any idea what could be causing this? Or any input on how I could resolve the problem?
Could this be the tires wear pattern?

Thanks in advance 🙏

[KHAP13]

- You could consider checking lower control arms. Other members reported wear in the ball joint which caused alignment to change/be unstable contributing to accelerated inside tire wear.
- Are you getting similar wear on street tires? If it has been a while since your alignment, you could consider checking toe.

I had similar wear on my street tires (old PSS) and also run AR1 (stock sizes) on track. With about 15 sessions / 500 track miles I didn’t encounter the same inside wear on the AR1, although they did wear odd around the tread pattern with raised lowered edges. I have similar alignment to you, -2.7 deg 1mm toe in.

From what I have seen on my car, I think -2.7 deg camber is unlikely to cause that accelerated inside tire wear especially if they are only driven on track.

[booya_45]

Maybe have another place check or set your alignment? How aggressive are you driving on cold tires when you first go onto the track? Are the front tires both wearing like this?

[Talx]

Originally Posted by KHAP13

- You could consider checking lower control arms. Other members reported wear in the ball joint which caused alignment to change/be unstable contributing to accelerated inside tire wear.
- Are you getting similar wear on street tires? If it has been a while since your alignment, you could consider checking toe.

I had similar wear on my street tires (old PSS) and also run AR1 (stock sizes) on track. With about 15 sessions / 500 track miles I didn’t encounter the same inside wear on the AR1, although they did wear odd around the tread pattern with raised lowered edges. I have similar alignment to you, -2.7 deg 1mm toe in.

From what I have seen on my car, I think -2.7 deg camber is unlikely to cause that accelerated inside tire wear especially if they are only driven on track.

On the road I’m running Cup 2’s which are getting a perfect wear pattern, 95% of the time I’m driving it hard on the weekends.
I cheack my alignment almost every other track day.
And I am running ball joints instead of all the rubber bushings on all the control arm links front and back.
Since the track has the majority of the turns in the same direction this is happening on the tire that is on the inside of the turn, I then switch them for the next track day.

If you look at a picture of me in a turn you can see that only the edge on the inside of the tire which is on the inside of the turn is touching the tarmac.

[bentom2]

I’ve encountered similar inner edge of inside tire wear when I would fall into a pattern of over-driving the front end of the car. Various track oriented tires and similar wear ( I have not tried AR1s). I had to consciously back off on entry speeds to reduce tire scrub, then focus on slow in fast out. It is much improved since I made an effort to adjust my driving style.

Aggressive corner entry feels fast as there’s a lot more going on, but I ultimately picked up improvements in lap times after going through this reset period. Moving up to advanced with lots of faster drivers in my group pushed me to drive more aggressively without much improvement in pace, but ultimately backing off produced better lap times once I adjusted.

Not sure if that’s your issue here, but maybe worth considering, or get someone in the right seat that can give you feedback. Sometimes it’s hard to self assess while you’re focused on pace.

Edit to add an equipment related possibility: The primary Nankang dealer here in the US (Phil’s Tire Service) makes a big thing out of heat cycling Nankang tires; essentially an easy session, then at least 24hours off the car for them to cure before going at pace. This has discouraged me from trying them as it’s not really how I want to be consuming the limited track time available to me.

[blitzyo]

Yeah they need one proper heat cycle, they understeer mad out of the box.
I get 5 track days out of mine, fronts insides are worn when rears are still good.
-3.5 camber up front and toe out. 31-33 psi hot.

[Talx]

Originally Posted by bentom2

I’ve encountered similar inner edge of inside tire wear when I would fall into a pattern of over-driving the front end of the car. Various track oriented tires and similar wear ( I have not tried AR1s). I had to consciously back off on entry speeds to reduce tire scrub, then focus on slow in fast out. It is much improved since I made an effort to adjust my driving style.

Aggressive corner entry feels fast as there’s a lot more going on, but I ultimately picked up improvements in lap times after going through this reset period. Moving up to advanced with lots of faster drivers in my group pushed me to drive more aggressively without much improvement in pace, but ultimately backing off produced better lap times once I adjusted.

Not sure if that’s your issue here, but maybe worth considering, or get someone in the right seat that can give you feedback. Sometimes it’s hard to self assess while you’re focused on pace.

Edit to add an equipment related possibility: The primary Nankang dealer here in the US (Phil’s Tire Service) makes a big thing out of heat cycling Nankang tires; essentially an easy session, then at least 24hours off the car for them to cure before going at pace. This has discouraged me from trying them as it’s not really how I want to be consuming the limited track time available to me.

Generally I would agree with you, but I have passed the stage of over aggressively driving the car, maybe you are right and I’m still too aggressive it’s a point I’m going to look into. but on the other hand my camber is not too big comparatively to other.

Also what is really bothering me is the fact that I am getting a wave pattern wear across the width where you can see I have marked in red the patch where the tire is also wearing out which is 3-4 of the way across the tire which I wouldn’t expect and I cannot explain.

Regarding the heat cycle I found this out the hard way on my first set of AR-1 I had where the first time at the track I didn’t get too much traction out of the tyre and then the second time out to the track day they performed much better, now I usually take the car for a spin a few days before I’m going to the track with a new set and heat them up.

[Talx]

Originally Posted by blitzyo

Yeah they need one proper heat cycle, they understeer mad out of the box.
I get 5 track days out of mine, fronts insides are worn when rears are still good.
-3.5 camber up front and toe out. 31-33 psi hot.

This only strengthens my thought that something is wrong, my front’s are getting hardly 5 track days out of them and with only 2.7 camber in the front not 3.5
I’m running a stg 2+ tune so the rear’s are also managing only 4-5 track days.
Maybe the width of the rim is causing this, it’s a 265 tyre on the OE width rim?

[Talx]

Better picture of the tire in question but this is an older set.
Anyone have any thoughts what could be causing such a weird wear pattern?

Someone suggested that my pressure is too low but I’m running around 35-37 hot which has given me an even heat distribution

[blitzyo]

Originally Posted by Talx

This only strengthens my thought that something is wrong, my front’s are getting hardly 5 track days out of them and with only 2.7 camber in the front not 3.5
I’m running a stg 2+ tune so the rear’s are also managing only 4-5 track days.
Maybe the width of the rim is causing this, it’s a 265 tyre on the OE width rim?

265 on OE wheel sounds too wide, but I forgot how wide they were. I have 265/35-18 on 9.5" wide wheels, a lot of people run them on 10" for optimal stretch.

[D.Yooras]

I agree, those tires are flopping around on the rim too much. You're pressures sound about right, may a bit low but not low enough to cause that by themselves (most optimal R compound tire hot pressures are 36-38 with peaks up to 40 but never over). One way to combat that would be to run higher pressures, that would lessen the flopping effect, but the tires are just too wide for proper support on those wheels.

When it comes to track tires, two things to keep in mind. One, R compound and most extreme performance summer tires, run 10-20mm wider than the "standard" tire in that same size. So when you're running the same size as stock, it's a "plus one" right away.

Two, rim width matters a lot. With the loads seen by a track going tire you'll never want to go below the "measured rim width" for that size and, because of the plus size issue, you'll want to add another .5" of rim width to keep fitment the same as it would be in a standard size. A perfect example of this is Spec Miata, they run a 205/50R15 which has a measured rim width of 6.5" but the spec wheel is 7" because of the plus one factor. If forced to run 6.5" the tires would have weird wear but on 7" they are very content.

The goal with track tires is to maximize the performance curve of the tire. Wider tires offer better performance curves which equals more grip but if the tire gets too wide for the rim, things could actual be worse than running a narrower tire. My advice would be to run your next set of R comps in the stock size and continue to check the temps and look for overheating marks (bluing on the loaded edges). If you're overheating the stock size tires, get wider wheels for that axle and repeat the process until you have tires that look happy near the end of their life.

General Width reference chart for R compounds
205 7"
225 8"
245 9"
265 10"
285 11"

[Talx]

Originally Posted by D.Yooras

I agree, those tires are flopping around on the rim too much. You're pressures sound about right, may a bit low but not low enough to cause that by themselves (most optimal R compound tire hot pressures are 36-38 with peaks up to 40 but never over). One way to combat that would be to run higher pressures, that would lessen the flopping effect, but the tires are just too wide for proper support on those wheels.

When it comes to track tires, two things to keep in mind. One, R compound and most extreme performance summer tires, run 10-20mm wider than the "standard" tire in that same size. So when you're running the same size as stock, it's a "plus one" right away.

Two, rim width matters a lot. With the loads seen by a track going tire you'll never want to go below the "measured rim width" for that size and, because of the plus size issue, you'll want to add another .5" of rim width to keep fitment the same as it would be in a standard size. A perfect example of this is Spec Miata, they run a 205/50R15 which has a measured rim width of 6.5" but the spec wheel is 7" because of the plus one factor. If forced to run 6.5" the tires would have weird wear but on 7" they are very content.

The goal with track tires is to maximize the performance curve of the tire. Wider tires offer better performance curves which equals more grip but if the tire gets too wide for the rim, things could actual be worse than running a narrower tire. My advice would be to run your next set of R comps in the stock size and continue to check the temps and look for overheating marks [...]

That’s interesting what you are saying because I have been wondering if my rims are not wide enough, I just want to add that this has been happening on both 245 and 265 wide tires, I have tried to go down from around 38 to 35 because I’m being told by most people that I’m going to high on the pressure, most people I talked to (on this forum) running AR-1 on an M2 are running eaven lower pressure at 32 PSI and my geometry calibrateor is telling exactly what you are that I should go higher on the pressure. So frankly I’m puzzled 🤔

[D.Yooras]

Originally Posted by Talx

That’s interesting what you are saying because I have been wondering if my rims are not wide enough, I just want to add that this has been happening on both 245 and 265 wide tires, I have tried to go down from around 38 to 35 because I’m being told by most people that I’m going to high on the pressure, most people I talked to (on this forum) running AR-1 on an M2 are running eaven lower pressure at 32 PSI and my geometry calibrateor is telling exactly what you are that I should go higher on the pressure. So frankly I’m puzzled 🤔

Interesting, what front sway bar and mounting position are you running?

[Talx]

Originally Posted by D.Yooras

Interesting, what front sway bar and mounting position are you running?

At the moment I’m with the OE sway bar.
I have a M2C racing set on the way.

I’m thinking maybe my suspension is too soft, this weekend I’m installing 120 NM springs in front and i definitely need a stiffer from sway bar with the body roll I’m experiencing.

I’m just not sure this explains the funny tires.
This weekend I’m going to try lower air pressure around 32 hot ( even though at 35-37 I was running the heat was ok across the width of the tire)
If that doesn’t work I’m going to go to 40 psi I just don’t know.

[D.Yooras]

Originally Posted by Talx

At the moment I’m with the OE sway bar.
I have a M2C racing set on the way.

I’m thinking maybe my suspension is too soft, this weekend I’m installing 120 NM springs in front and i definitely need a stiffer from sway bar with the body roll I’m experiencing.

I’m just not sure this explains the funny tires.
This weekend I’m going to try lower air pressure around 32 hot ( even though at 35-37 I was running the heat was ok across the width of the tire)
If that doesn’t work I’m going to go to 40 psi I just don’t know.

The springs are a little on the soft side but the OE anti-roll bar is not sufficient for track use. The reason you're getting that odd wear is because the tire is never quite flat on, or consistently planted on the ground so it's deflecting and squirming around on the rim.

My advice is to get a big front bar (around 30mm) to limit the front axle body roll and improve the weight transfer characteristics of the front axle.

[Talx]

Originally Posted by D.Yooras

The springs are a little on the soft side but the OE anti-roll bar is not sufficient for track use. The reason you're getting that odd wear is because the tire is never quite flat on, or consistently planted on the ground so it's deflecting and squirming around on the rim.

My advice is to get a big front bar (around 30mm) to limit the front axle body roll and improve the weight transfer characteristics of the front axle.

Thanks for all the input 🙏
Really appreciated
I have the M2CS racing anti roll bar for the front and rear on the way, I installed 120 front springs this evening and I’m at the track on Friday, I will update with how it turned out.

Next thing on my list is a proper set of rims for the track.

[Track/S]

I would never use a 265 track tire on a 9 rim.

[Talx]

Originally Posted by Track/S

I would never use a 265 track tire on a 9 rim.

I get is but Nankang does recommend 9-10.5 with rim for this tire.

[///393]

~12psi swings are challenging because inevitably you’re doing 2-3 laps with some fairly low pressures not to mention the TPMS headaches.

I ran my RT660 to 26-37 and corded the outside edge of the outside tire as a result. 32-43 provided better wear but that last 3psi is more than I want.

Have you considered nitrogen fills? Is that a thing?

[Talx]

Originally Posted by wilson kop

~12psi swings are challenging because inevitably you’re doing 2-3 laps with some fairly low pressures not to mention the TPMS headaches.

I ran my RT660 to 26-37 and corded the outside edge of the outside tire as a result. 32-43 provided better wear but that last 3psi is more than I want.

Have you considered nitrogen fills? Is that a thing?

Ok, well I was at the track on Friday and decided to try to go to a higher pressure because i met two guy’s with Z370 running Nankang AR-1’s and they told me they where at 42 PSI getting a perfect wear pattern and long life out of the tires( they also thought that my wear was due to low pressure. So I tried the high pressure, it was a cold day so I started at 34 cold only problem is that by the time the tires where getting up to heat the front’s inner edge where goners and I had to stop 🤦🏻‍♂️

I don’t understand how everyone on this forum are claiming to run 32 hot on this tire.

In regards to the nitrogen, personally I don’t believe that it would solve the problem and it’s to much time consuming and complicates things to much.

[///393]

Yeah it sounds like you and I just trashed fronts as a way of learning the tires need more pressure. My rears didn’t see nearly the same level of inner/outer wear as they’re not nearly as loaded as the fronts and can get by.

I don’t have a pyrometer but will be using one next outing with a fresh set of fronts to confirm this hypothesis but after one day of running higher pressures I’m seeing more even wear.

Expensive lesson to learn but so it goes.

[Talx]

Originally Posted by wilson kop

Yeah it sounds like you and I just trashed fronts as a way of learning the tires need more pressure. My rears didn’t see nearly the same level of inner/outer wear as they’re not nearly as loaded as the fronts and can get by.

I don’t have a pyrometer but will be using one next outing with a fresh set of fronts to confirm this hypothesis but after one day of running higher pressures I’m seeing more even wear.

Expensive lesson to learn but so it goes.

That’s the thing I was getting a perfect heat range (using a pyrometer) when I was running the tire at 40 psi but kept getting told I’m running a too high of a pressure and that I should lower it, instead of l listening to my self I gave in to others opinions, top it off with the fact that any one using this tire on the m2/3/4 forum claims to be running it at 32 psi and what you get is a situation where you are causing a problem that didn’t exist in the first place I’m guessing.

Next set that goes on the car I’m going to go to 40-42 high pressure and check the heat range again and see from there 👍