[D.Yooras]

Originally Posted by Talx

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.

People run lower pressures because it can make car with an improper camber curve (ie any strut car) feel like it grips better. Running the tire with less pressure will allow the tire a slightly bigger footprint while also allowing more deflection which helps even out the unit loading of the tread...sort of. What it re

What it really does is allow the tire flop around and seem like it's giving better grip while making it handle and feel horrible. Most of the time what's actually happening is the tire doesn't produce as grip as it would with higher pressure BUT in doing so, the body roll of front axle is reduced as well. This gives the perception that the car is handling better even though it's highly likely that it's not. Again, a properly setup front strut car will be at, or near, 100% lateral load transfer on the front axle during heavy cornering which means all the weight on the front axle is on the outside tire. More weight means more tire pressure is needed.

It's better off to run higher tire pressures and find the proper camber/roll stiff settings than turn the tire into a sloppy mess.

[MadM2C]

the AR1 runs pretty narrow, I use a 265/35 on my oem 9" wheel and have no experienced such uneven wear, Even being with over -3 degrees of camber. I would make sure the toe is in spec.

[Talx]

Originally Posted by MadM2C

the AR1 runs pretty narrow, I use a 265/35 on my oem 9" wheel and have no experienced such uneven wear, Even being with over -3 degrees of camber. I would make sure the toe is in spec.

Ok, how much pressure are you running hot?

In regards to toe as I mentioned I’m running 0.008 toe in in the front, and I get an alignment just about every 3 track days to make sure it’s in spec.

[MadM2C]

Originally Posted by Talx

Ok, how much pressure are you running hot?

In regards to toe as I mentioned I’m running 0.008 toe in in the front, and I get an alignment just about every 3 track days to make sure it’s in spec.

Hot pressures are 32-33 degrees.

I'm running 1/8 total toe in rear, 0 toe front.

[Talx]

Originally Posted by MadM2C

Hot pressures are 32-33 degrees.

I'm running 1/8 total toe in rear, 0 toe front.

I’m running the same toe front and rear (0.008 in the front is negligible)

With 2.7 camber front and 2 in the rear

I’m not sure how you could be running such a low hot pressure and not getting inner and outer wear, you had the set for sale, did you run a similar set to the end of its life?

[///393]

Originally Posted by Talx

I’m not sure how you could be running such a low hot pressure and not getting inner and outer wear, you had the set for sale, did you run a similar set to the end of its life?

Was thinking the same. Assuming 8psi of pressure delta at minimum this does seem crazy. I know they’ve got a stiff sidewall but going out with 22-24psi just seems super low.

[booya_45]

Originally Posted by wilson kop

Was thinking the same. Assuming 8psi of pressure delta at minimum this does seem crazy. I know they’ve got a stiff sidewall but going out with 22-24psi just seems super low.

This is what I was thinking as well. I’ve taken a lot of life out of a set of tires doing this. Going out too hot and not letting tires adequately get up to temp before pushing the car.

[MadM2C]

Originally Posted by Talx

I’m running the same toe front and rear (0.008 in the front is negligible)

With 2.7 camber front and 2 in the rear

I’m not sure how you could be running such a low hot pressure and not getting inner and outer wear, you had the set for sale, did you run a similar set to the end of its life?

Yes i've ran AR1s since they were released, and I will be purchasing them again, however this time it will be with an 18" wheel and square setup.

My good friend who also runs AR1s on his f82 runs them at 38psi hot, but we noticed his tires will start to get greasy about 10 minutes in our 20 minute session, where mine stay consistent for the entire 20 minutes. This was originally why I started keeping them at lower pressures.

[D.Yooras]

Originally Posted by MadM2C

Yes i've ran AR1s since they were released, and I will be purchasing them again, however this time it will be with an 18" wheel and square setup.

My good friend who also runs AR1s on his f82 runs them at 38psi hot, but we noticed his tires will start to get greasy about 10 minutes in our 20 minute session, where mine stay consistent for the entire 20 minutes. This was originally why I started keeping them at lower pressures.

Properly inflated tires will have a better contact patch, which will generate more grip, that leads to hotter surface temperatures, that, if they exceed what the compound is designed for, will result in a greasy inconsistent feel. Lowering the tire pressure is likely decreasing the level of grip the tire is capable of producing which is decreasing the temperatures the tread compound is being exposed to.

All tires have a performance curve that depends on a multitude of factors like tread compound, durometer, and overall stiffness of the carcass of the tire itself. If the performance curve of a given tire is exceeded, it will become greasy and inconsistent much the same as brake pads that have become to hot. This is generally due to the compound beginning to sheer at a higher rate due to surface temperatures beyond what it was designed for.

In this case, the likely reason this happens is because the tire is being taken beyond it's performance curve, likely due to the compound being too hard for the usage the tire is seeing. The way to fix this problem is run a wider version of the same tire or switch compounds and/or use a different tire.

Lowering the tire pressure is more of a workaround than a solution to limit grip on the front axle.

[Talx]

Update:

I installed a set of MBW M2 CSRC sway bars front and back together with the upgrade to 120 springs in the front and was at the track last weekend. Kept an eye on tire temperature across the width of the tire after each session and it looks like the optimum tire pressure was 43 PSI in the front and 37 in the back. After about 50 laps it looks like I’m finally getting even tire ware, although I won’t really be sure for another 1-2 track days but it’s a promising start.

[booya_45]

Damn. 43psi sounds kinda high to me. Im far from a professional though. Do you remember what the tire temps were?

[medphysdave]

Cup 2 connect are in their sweet spot between 37 and 43

[Talx]

Originally Posted by booya_45

Damn. 43psi sounds kinda high to me. Im far from a professional though. Do you remember what the tire temps were?

That’s what I was thinking so i tried lowering the pressure which only resulted in worsened results.
My front where running between 70-75 C
And the rears around 60

[Talx]

Originally Posted by medphysdave

Cup 2 connect are in their sweet spot between 37 and 43

Actually with Cup2 connect which I run as daily’s ( mostly pushing it on back roads) I find that 32-35 psi how is the best and I’m getting a perfect ware pattern

[medphysdave]

Originally Posted by Talx

Actually with Cup2 connect which I run as daily’s ( mostly pushing it on back roads) I find that 32-35 psi how is the best and I’m getting a perfect ware pattern

My fastest laps at CMP (1:48.0)were with hot pressure between 36 and 38psi. The track connect app shows the ideal temp ranges for the cup2 connect. I drive them in the winter starting at 36psi on the street. In the summer I start at 35psi at ~70F. This gets them into ideal pressure range during my commute. I was able to get 17k mi and a track day out of that set.

Sorry for the off topic. Point was that some of these tires seem to like pressures that previously would be considered way to high

[johnny_slo]

Hi! I see OP is running 265/35/19 front. Is there any rubbing? I'm on nankang CR-S right now, runing 265/30/19 and it's ok, before that I was running Trofeo R 275/30/19, no rubbing as well. Hight of AR-1 being 35 has always worried me as I assumed it's going to rub.

Additional question. Has anyone used AR-1 305/30/19 at the back?

Please mind I have 3+ degrees negative camber front and 2+ negative camber back, running Protrack One wheels of proper sizes for these tires.

Thank you!