Do I need to roll my fenders?
 

I tried searching, but couldn't find a definitive answer, since most people seem to be running at European ride height.

I have an '87 coupe that I have set at stock US ride height. I picked up a set of 16x7 and 8 Ronal R9s with Toyo R888s and I'd like to run a few autocrosses with them. The front tires are 205-55-16.

Ordinarily, I'm not opposed to rolling fenders, but in this case, it's a relatively unmodified car with original paint and I'd like to avoid that if possible.

http://images.thesamba.com/vw/classi...ix/3615199.jpg

205 55 16" is a stock factory option so no fender rolling required for US ride height.

Yes, in fact that's the size that came on my car, but they were on 6 inch wide wheels. These are 7.

Your '87 from the factory sets at "Euro" ride height. When I had 16x7's with 205/55-16's @ Euro ride height, stock torsion bars, stock sway bars, and 0 degrees of camber, I had no rubbing issues. When I lowered it a 1/2" with a little less than -1 degree of camber, it rubbed on the driver's side, so I trimmed the fender lip. Do it doesn't rub again.

I would say you do not need to. ET23 on a 7" rim with a 205 tire I believe you should be fine and especially since you are at spec height. If you were running a 225 tire you might run into slight issues, but probably not. I am running a 225 on an 8" rim up front and I had to roll my front fenders a medium amount. It was fairly simple to do and no paint chipping happened in the process.

Its an easy test... put the wheels on, crank the steering, put your well proportioned wife/mistress on the fender and roll the car around :) If it rubs you can roll it and re-test ;)

Both my wife and mistress are quite slender, so I would have to put them both on there, but that would probably negate the whole "original paint" issue.

the rolling fenders issue with 7x16 wheels up front stems from the offset that 7x16 fuchs wheels use vs the offset used by 6x16 fuchs. I see that you're using ronals -- and have no idea of what their offset is. If they're not effectively pushing the outer edge of the tire toward your fender (like the 7x16 fuchs do), you should be good to go with 205/55 -- if their offset is identical to 7x16 fuchs, you may well need to roll . . .

One good/easy test is to use chalk to markup the sidewall of your tires and then drive and see what (if any) scuffs off

I know exactly what the offset is. It is 23mm. (See the attached photo).

7 inch wheels with ET23 should be just right for the front. I have 15x7 ET23 Fuchs up front with 205/55-15 tires and there is plenty of room. The 6x16 Fuchs wheels had ET36 which pushed the wheels about 1/2" farther out (as stated above).

Just the opposite. 7x16 with ET23 pushes the barrel 1/2" farther out than a 6x16 wheel with ET36. The lower the offset (ET number), the farther out the wheel goes.

Oops, you are right. I should know better. My rear wheels are 7x15 ET10.6 which does push them out.

205/55's on et23 16x7 wheels *can* rub. Since you're autocrossing with higher grip tires, if it can rub, it will!

IMO, put the 205's on some 6" fuchs and have no worries. I appreciate stuffing all the tire you can under the fenders, that's what I do, but it doesn't sound like that is your primary goal.