I’m trying out a new tire/wheel setup for the track and need some feedback about the minimum clearance between the tire sidewall and strut. With a 25mm spacer I have 2mm clearance. I have driven on the street with them and there is no rubbing, but I don’t know if there could be any deflection on the track which could cause rubbing. Is 2mm sufficient clearance for track use?

definitely tight. but deflection shouldnt cause an issue since it'll be back on the right part of the rim by the time it rotates up there. I've run with a couple of mm clearance. It could become a problem with taller tires that flex more, tho. FWIW - I ran 31mm spacers and found them to be the sweet spot

honeybadger said:

definitely tight. but deflection shouldnt cause an issue since it'll be back on the right part of the rim by the time it rotates up there. I've run with a couple of mm clearance. It could become a problem with taller tires that flex more, tho. FWIW - I ran 31mm spacers and found them to be the sweet spot

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Thank you! The 2mm clearance is with Apex 19x11 ET52 and Continental ECF 315/30/19. I first fit them with a 28mm spacer, and running -3.4 camber they seemed really close to the fender so I was worried they would rub under compression while turning. I switched to a 25mm spacer and the fender fit is still tight, but at least gives a little more space.

The 2mm clearance might be tight for the track depending on your tire selection. I've experienced some strut rubbing on the track with 25mm spacers, Apex 19 x 11 ET52 wheels and 305/30-19 Goodyear 3R's. I did not experience any rubbing with the same tire and wheel combo and 28mm Apex spacers or 30mm MMR spacers. I also used Falken 660's and Hoosier TrackAttackPro's with the 28mm and 30mm spacer combination without experiencing any strut rubbing. The car is a mostly stock 2021 Mach1 that's only used for track days and time trial/time attack at BRP Classic, CVR, ORC-LVMS, Spring Mountain, and WSIR.

krisk said:

I’m trying out a new tire/wheel setup for the track and need some feedback about the minimum clearance between the tire sidewall and strut. With a 25mm spacer I have 2mm clearance. I have driven on the street with them and there is no rubbing, but I don’t know if there could be any deflection on the track which could cause rubbing. Is 2mm sufficient clearance for track use?

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I've always considered 5mm the minimum gap sidewall to anything.

JAJ said:

I've always considered 5mm the minimum gap sidewall to anything.

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Thank you for the feedback. Is your 5mm guideline based on known issues with running less than that amount or some other reason?

Is this the same size tire, or were you running the 295 previously?

Junkyard Dog said:

Is this the same size tire, or were you running the 295 previously?

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I was running 295/30 previously.

krisk said:

Thank you for the feedback. Is your 5mm guideline based on known issues with running less than that amount or some other reason?

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I've had rubbing and that spacing fixed it.