Need help with tire size for the track

[Tommy L Garage]

Hi There. I used to rtrack my OEM 513M wheels with stock tire sizes 255F 275R 40 sidewall.

I recently picked up a used set of four Apex EC-7 ET25 and hoping for a square setup to be able to rotate tires better.

Can I run 275/40/18 all around? I know some suggest 35 sidewall but that is just so much smaller than OEM.

Will I rub with 275/40 in the front? And if so, will spacers fix the issue?

I plan on getting Toyo Proxes


Thanks!

[fanatic1]

Originally Posted by Tommy L Garage

Hi There. I used to rtrack my OEM 513M wheels with stock tire sizes 255F 275R 40 sidewall.

I recently picked up a used set of four Apex EC-7 ET25 and hoping for a square setup to be able to rotate tires better.

Can I run 275/40/18 all around? I know some suggest 35 sidewall but that is just so much smaller than OEM.

Will I rub with 275/40 in the front? And if so, will spacers fix the issue?

I plan on getting Toyo Proxes


Thanks!

Not sure which Toyo Prox you’re thinking about, but you can do much better. Check this thread out for some good information on tire choices for track day:

https://f80.bimmerpost.com/forums/sh....php?t=1686961

[jmg]

Originally Posted by Tommy L Garage

Hi There. I used to rtrack my OEM 513M wheels with stock tire sizes 255F 275R 40 sidewall.

I recently picked up a used set of four Apex EC-7 ET25 and hoping for a square setup to be able to rotate tires better.

Can I run 275/40/18 all around? I know some suggest 35 sidewall but that is just so much smaller than OEM.

Will I rub with 275/40 in the front? And if so, will spacers fix the issue?

I plan on getting Toyo Proxes


Thanks!

Hey Tommy, love your channel btw! If you rub, I think it will be the outer shoulders of your tires with either the fender liner or the painted fender lip, depending on how low you are of course. I don't think a spacer will solve any problems unless you aren't clearing your suspension, which isn't likely since that is more related to too much offset. The ET25 is standard for the fronts. If anything, the spacers will cause rubbing.

[SYT_Shadow]

Run 275/35 18 like everyone else

[MaX PL]

just an FYI but be prepared to run DSC off if you want to run a square setup.

I did this my first year out and was way down on power with MDM on + square setup. Once I went back to staggered the power issue went away with MDM on.

I met a guy at Watkins last year who had the same problem, thinking I had a tune as his car was slower than mine. His was a competition and mine is base with the problem being his square setup.