how well do 255s fit on 2nd gen
 

I've been finding some conflicting info.

Looking at possibly moving out of street class (scca autox) with my 2nd gen. I conveniently have a brand-new set of 255/40/17 v730s and also a set of 17x9 +42 wheels (Mach V Awesome) left over from my old STi.

I know this fitment is great on a first gen, sounds like maybe the 255 is tough to fit on the 2nd gen though?

I'd be looking to lower the car on coilovers and run appropriate camber for autox.
Not interested in cutting into the car in the rear to make it fit.

I'm not really aiming for any specific fitment / looks or anything, I don't mind a slightly higher ride height if that's what it takes. But it would be nice to not have to go buy 245s when I already have the brand new 255s ready to go.

Depends on your setup. I have a similar configuration 17x9 +42. Works well with most of 245, does rub with Hoosiers and would expect to rub with 255 in my case. Main issue is the tab. You can try it and may need to add RLCA and RUCA. I would suggest to go in steps.
All 255s I saw so far had the tab shaved or at least grinded.
I may try the Hoosiers again next year, and will update the suspension to make it fit before anything else.

Good luck

Appreciate it.

For anyone else looking, I ended up going with 245s. That was the right call. 245/40/17 on 17x9 +42 was wide enough in the rear to sure make me question if it was going to rub or not. I didn't have any trouble though.

I ran -2.6 camber front and -2.0 rear. Car is lowered one inch so 13.5" hub center to wheel arch in the rear. However, the springs on the new coilovers did settle pretty dramatically at the first autox event so I can confirm it still doesn't rub even on a rough course and rough roads at about 1.5" drop (about a single finger gap) in the rear.

I've heard some people at the national level running 265's on the first gen. I know we're talking about the 2nd gen here, but they're very similar.

I went to STX/DST last year and glad I went with 245/40/17 on a 9" wheel and +35 offset. A052's rubbed on the inside of the front at full lock on one side, wearing away paint on the chassis. Not sure how people are running 255's or even 265's. They must just be going for all out times at the expense or rubbing and not being able to go full lock in grid or on the street.

If you're going with +42, there's zero way 255 or larger is going to fit. I can't imagine there are loads of gains in times with a 255 or 265 when you start factoring in tire weight increases.

17x10 with a 255 fits on a second gen if you're running the proper amount of camber.

There is a TT5 car with this setup, also for our NASA people - 255/40/17 RC1 on a 10 fits into the 257mm template.

https://i.imgur.com/Mzkh37d.jpeg
https://i.imgur.com/LpkcuGo.png

1st gen has a lot more room in the rear. We ran 275s just fine on my gf's 1st gen track car. She had a lot of camber at the time though and they were on the smaller side for 275s.

I was mostly just hoping to reuse a set of wheels and tires I already owned. Oh well. The wheels fit great and 245s were the right call.

I'm interested in the first gen part of the conversation. I'm thinking of moving to 18x9.5's and 285's in the rear. I haven't checked for clearance just yet though. Do any of you have experience with this?

None here. I will say that we ran 17x10 +45 with 275 width 615k+ tires on a first gen and had no issues aside from a slight rub in the front near full lock. Really only showed up in the paddock, never got close to that much steering angle on track.

The car did feel pretty lazy with that setup though and we ended up preferring 255s. Might've felt better on a better tire? Car is / was supercharged so it was more a feeling of lacking steering response vs a feeling of lacking acceleration.

That's very helpful. I don't plan to run wider tires on the front (245/255) but the rear is what I'm interested in checking.