Goodyear Eagle F1 SC3 285/30-20 w/ Load Index of 95, too low for the rears?

[Bon F80]

Hi guys. I'm currently running Cup 2 285/30-20 on 20" x 10.5" ET34 wheels. I'm also having KW Clubsport with the car lowered quite extensively (probably the maximum or too low for HPDE trackdays where my fender liners have to be modified to avoid rubbing) and camber of -2.2 at the rear.

Just got myself Goodyear Eagle F1 SC3 295/30-20 for the rear as the Cup 2 replacement. I knew it's quite a bit wider from the specs I found on Tirerack but after looking at the actual tires today, they look really wide in comparison and I'm thoroughly concerned if they can fit my car. I know it's not the best for HPDE trackdays but I do not want to raise the height on my suspension (and it's a big hassle to adjust the height of the rear KW Clubsport due to the external reservoir which reduces the space you need when using the wrench).

So I'm re-assessing if I should go with Goodyear Eagle F1 SC3 285/30-20 instead. I didn't want to go with 285 in the first place because it has a load index of only 95 (much lower than the 99 used in most BMW OE applications for the F8x platforms).

My questions are:
1) is a tire with load index of 95 safe for HPDE trackday usage on the rear of M3/M4?
2) do you have a similar setup (i.e. Goodyear Eagle F1 SC3 295/30-20 on 20" x 10.5" ET34 wheels, with the car lowered and camber of around -2 at the rear)? Is there any rubbing?

[Bon F80]

doing a test fit of the 295/30-20….dang it looks like it will definitely rub especially under cornering load on a HPDE track day…

[biofluke]

You might be surprised. I think you might be good. The rear suspension pushes the wheel inwards.

Im running 295/35/19 Falken RT660 and I swore it would rub. Turns out it only ever so slightly grazed the plastic inner wheel well protector. After a few weeks, it stopped rubbing, so it must've slightly shaved down whatever plastic it was making contact with. This also only happened while going up steep driveways on an angle, and did not happen during the 2 track days I did with them. You could also max out the rear camber to 1.8 - 2, if you haven't already, to get a little more clearance.

Few pics of my barely fitting setup for reference.

[Bon F80]

Thx a lot biofluke !

Yes I'm running -2.2 camber at the back already. What are the size and offset of your rear wheels? The rate that they poke out is definitely similar to mine judging from the photos.

I know the photos do exaggerate the gap between the tire and the fender, but I do think your car is sitting slightly taller than mine. Guess I have no choice but to raise the height of my car in order to run these tires on track.

Much appreciated!

[biofluke]

Originally Posted by Bon F80

Thx a lot biofluke !

Yes I'm running -2.2 camber at the back already. What are the size and offset of your rear wheels? The rate that they poke out is definitely similar to mine judging from the photos.

I know the photos do exaggerate the gap between the tire and the fender, but I do think your car is sitting slightly taller than mine. Guess I have no choice but to raise the height of my car in order to run these tires on track.

Much appreciated!

19x9.5 et 22 front, 19x10.5 et 35 rear. 265/35/19 front, 295/35/19 rear, Falken RT660 tires.

Track photo from NJMP, with tires in action, for reference attached.

[vrptstyly]

NJMP Lightning.

[Pworld10]

OP. Do you have pics of your car on the 285-30 cup 2? I have this same tire and rear wheel dimensions waiting to go on and would love to see it on an aggressive lowered car.

[Wanted_M]

Why the change from the Cup's?

[Bon F80]

Originally Posted by Pworld10

OP. Do you have pics of your car on the 285-30 cup 2? I have this same tire and rear wheel dimensions waiting to go on and would love to see it on an aggressive lowered car.

@Pworld10 , I don't have any photo with me at the moment, maybe you can find some from my IG for now.

[Bon F80]

Originally Posted by Wanted_M

Why the change from the Cup's?

Hi Wanted_M , I do enjoy the performance of the Cup 2 on track. I'm currently stuck with Cup 2 however because I'm running 20" wheels at the rear. I want to try the highly praised TW200 tires on track for comparison. Maybe next year if I have a chance to switch to 19".