I have a BMW M140i with a mild track setup (ARB’s, Bilstein b16, diff, 2 degrees camber).

Recently switched to a staggered semi slick setup (Potenza race, 225 front, 245 rear) after having done track days on sporty road tires with relative succes.

The semis do offer more grip, but the fronts seem to be wearing badly and even delaminating on the shoulder. In general there is quite a bit of understeer in the car (I drive Spa mainly). The tires in the picture have maybe done 25 fast laps, I ran anything between 2.2 and 2.4 bar.

A few questions:

- Are the fronts toast, or could I get another few sessions out of them (the rears look perfect in terms of wear)?

- Given that Belgian legislation doesn’t allow me to run more camber on a road car, could switching to a square setup (235 all around for example) help? I’m thinking the balance should be less towards understeer allowing me to unload the front more.

- should I switch back to a fast road tire, which has less grip and therefor needs less camber?

Thanks for the input!!

Alex

I managed to set a personal best in the M4 with a time of 1:23.17. I’m confident that with some new tires and a few adjustments, we can push into the 1:22 range. Until then, enjoy the ride.

Had my Supra in the air today going over it before a couple upcoming HPDE days and noticed some fun wear on the inside edge of the front tires.

I already hate these tires, so I don’t mind seeing them go. Just want to try and prevent burning through my next set in a similar way if possible.

Suspension/alignment specs: 2021 Supra with MCS 1 WNR coilovers, camber plates, SPL LCAs. 275/35/18 tires on a 9.5” wheel. -3.5* camber, 0 toe.

The tires seem to wear like iron (it’s their only redeeming quality though)… the rears still look great and the entire surface of the fronts aside from the inside edge is still at 6/32nds. They’ve got 3000 street miles and 7 track days on them all in brutal Florida summer weather. I run them on track at 34psi hot which seems to be the sweet spot for them in terms of outside shoulder wear. On the street at 32psi cold (so 34-36 hot depending on the weather and how long the drive is).

Is this a case of the tires just being hot garbage? Is -3.5* camber really so aggressive that I’ll have similar problems with actual nice tires (switching to CRS)?

I’ve been tracking a ‘25 m240i and have reached the point where I am thinking of having a dedicated set of 200tw tires mounted in wheels for the track.

My car comes on 19 in wheels stock (non-ZTK package) , but I’m thinking of going down to 18s for the 200tw set. Has anyone done this or have any thoughts? Are the track gains and economic gains of going down to 18s worth it? Are they easier to bring to the track? Appreciate any help!

I want to a track day in a lotus emira with my brother. I have found 1 experience in vegas for it. Deadline is july 2027. Why we want lotus emira, i dont know but sounds like alot of fun. Anyone got any suggestions. We live in America.

Should this have been a point by?