DanielB

I missed your response earlier - what tire are you using? I ask because I've seen large variation in the width of tires from different manufacturers in the same size.

Manga_Spawn

The tabs are not what gets caught. The little lip between the tabs are what gets caught.

DanielB

I looked at it last night and see what you mean - the initial contact will be with the liner lip and edge of tire. The wheel would have to compress further into the wheel well in order for the tabs to make contact.

circuitclub

I've been told Volk ZE40 17x9 +61 clears Stoptech BBK; next best wheels are ~+50 which will need a roll - I believe.

s2000Junky

These would be your best fitting option as far as offset for your outer fender, still may rub on the inside with 255 but that's far less an issue if you do.

DanielB

Thanks for the suggestion, they are very nice wheels, but too expensive (~$3K per set) for track wheels for me.

I've seen a few threads where the 17x9 +63 Nurburgring (which clears Stoptech ST40) has rubbing issues at full lock between rim inside and control arms. So then it would need a spacer which I'm not interested in doing for a track car. So I'm thinking the +55 offset of the 949 6UL might be the best compromise with the potential need to deal with mild rubbing on the outside fender. S2000Junky, I'm coming around to your advice to just accept that I'm going to have to do some fender mods if I want to go 17x9 square and BBK.

I'm leaning towards buying a set of 949 6UL in 17x9 +55 and buying two 255 tires and test fitting them on the front. I could also track them with my current 255 track tires on the rear. From there I'd know if there are rubbing issues up front, and if I want to either do a mild fender roll and buy two more 255s, or switch to a narrower 235 front and live with that.

circuitclub

It's really tricky, they will either rub on the inside or outside - 255s seem to get wider every year and the car was not designed for the width + low height. I think the best offset is ~50 with a good fender roll.

s2000Junky

Yep pretty much. But if your going to the hassle already, in my view get a better performing package and go all out with a 10" rim width to maximize grip and feel of those wide 255's. Its easier to get a fitting offset in a 10" wheel that accommodates a BBK anyway. 10" +55 is pretty ideal, smack dab centered in the wheel well. Good roll and little pull up front and your running a healthy package with a BBK. I started out with the convex face RPF1 8.5" +40 and cut/welded another 1.5" to the inside to effectively make it a 10" +58 and it accommodates my trophy kit with 12mm to spare. Sometimes you have to think creative to get around lack of options, so I made my own solution. After fitting a custom widened 11.5" in the rear with a 315, it made the front feel pretty easy to deal with, and went ahead and upped it this year to a 275/40. Raised the ride height a little to make room for the taller tire and a little more fender pull to help when the wheels are turned under compression. Honestly I may go back to a 255 up front, because the sidewall increase is just too cumbersome and probably makes the added width a wash from an aerodynamic and feel perspective at least on the big track. I wish someone made a 275/35/17 and a 315/30/17 cutting the overall diameter down to closer spec sizes.

Bullwings

I had rubbing on the fender liner running the OEM 17x7F with 225s. I was on stock suspension.

If you track and have high compression points (steep banking), even the OEM setup risks rubbing.

255 square on any 9" setup is going to require you to at least bend the tabs up, especially with a soft setup like the DFVs (are you doing the revalved option with 12kg front and 10kg rear, or factory Ohlins?).

I see no reason to not at least flat roll the fender, unless you're building to a specific competitive class that does not allow it.

DanielB

Yes, I looked up into the wheel well and noticed there are rub marks on the top of the fender liner on both sides. But I don't know if they are from before or after switching to the Ohlins. So far I have been using AP2V1 wheels with 225 in front.

I have the SakeBombGarage version with 11kg front and rear and shocks revalved to match. Front is only lowered to 13 3/8" so not very aggressive. I'm hoping the stiff springs will limit travel vs. stock to compensate for the lower ride height.

No class rules - just me driving HPDEs. Please help me as I get myself familiar with the world of fender rolling: what does "flat roll" specifically mean? Is it rolling the lip of the fender so it's flat against the inside of the fender?