[GreepM]

Hi guys,
30min stint on track ended on front tires like this....is it overinflated? Let me know your thoughts, thx.

pressure 38F 42R, M adaptive suspension, RWD

[Wires]

That would be my guess. It looks like you are losing lateral grip and sliding sideways.

[jmg]

38 is borderline high, but that depends on your tires. I try and keep my tires below 38 on the track. The wear looks about right if you are on factory setup, there is some corner wear. Most cars require camber to keep wear even on the track, about -2.7 to -3.0. So yes, that's "normal" but it isn't ideal, but it isn't nearly as bad as I've seen before.

Your rear pressure is too high.

[ChuckP49]

Tyre pressures too high. Some tracks are more abrasive than others, and the tyre compound is a huge factor, which Goodyears are they?

[Desertnate]

While the pressure might be a little high, I don't know if lowering it much would help.

The first picture makes it look like there is wear on the side of the tread block all the way down to almost the sidewall. At the very bottom of that picture you can faintly make out the inverted "V" symbol marking the edge of the tread and the start of the sidewall.

[thejeremyman9]

Originally Posted by Desertnate

While the pressure might be a little high, I don't know if lowering it much would help.

The first picture makes it look like there is wear on the side of the tread block all the way down to almost the sidewall. At the very bottom of that picture you can faintly make out the inverted "V" symbol marking the edge of the tread and the start of the sidewall.

Same comment. Lowering tire pressure will improve grip but you dont want to have so much deflection under hard cornering that you go past the line on the tire.

I would run 32/35 F/R and check it after each session because it has probably went up.

To me the wear looks normal, about the same as my brand new tires did after 13 autocross laps. Plowing through corners with understeer will make things worse so make sure you arent going in too hot.

[HighlandPete]

Originally Posted by Desertnate

While the pressure might be a little high, I don't know if lowering it much would help.

The first picture makes it look like there is wear on the side of the tread block all the way down to almost the sidewall. At the very bottom of that picture you can faintly make out the inverted "V" symbol marking the edge of the tread and the start of the sidewall.

That's what I'm seeing. Surely the comments some have made on lowering the pressure will mean even more roll over onto the sidewalls.

[GreepM]

Originally Posted by ChuckP49

Tyre pressures too high. Some tracks are more abrasive than others, and the tyre compound is a huge factor, which Goodyears are they?

It's F1 SuperSport 225/45/18

(..it's also my daily, so bigger sidewalls...and 255 on the rear makes the car quite understeer so... maybe next time I'd go 235/40F and 245/40R)


maybe because of the bigger sidewalls the pressure went to 38s idk...I'm not scientist


Still asking myself, when the car is 50:50 weight ratio, why the rears should have more pressure?

Next time I'll try 32F square or 30/32 F/R hot

[GreepM]

Originally Posted by jmg

38 is borderline high, but that depends on your tires. I try and keep my tires below 38 on the track. The wear looks about right if you are on factory setup, there is some corner wear. Most cars require camber to keep wear even on the track, about -2.7 to -3.0. So yes, that's "normal" but it isn't ideal, but it isn't nearly as bad as I've seen before.

Your rear pressure is too high.

thanks, you're right. Front camber sucks compared to rears which are in better shape. It's noticeable by just a look. Also me driving won't help much

[N55ryan]

looks to be from overinflation

[Desertnate]

Originally Posted by GreepM

Still asking myself, when the car is 50:50 weight ratio, why the rears should have more pressure?

You can slightly change the car's understeer/oversteer behavior depending on pressures. It's really the autocrosser's only weapon in a stock class and I'm sure BMW did the same thing as they dialed in the handling for the car.

[GreepM]

update:

yesterday 32/34 hot (started with 26/28 btw)

DSC OFF !!! I'd say, when you have it ON the car is quite a lot understeer.
I was fighting only with oversteer, which was super fun, only once went wide in to the gravel

I don't know if it's mainly because of the pressures or DSC off, but I enjoyed the whole session.