krp220

Afternoon,

before I get flamed with the “bUt diD YOu seaRcH!?” comments, yes- I certainly did. With that being said, I’m having analysis paralysis and could use the external input before dropping several thousand dollars on custom forged wheels. I’m not getting a ton of insight from the supplier and trust you guys more

so,
how does this sound? I’m going for that meaty tire look but do not want to roll fenders (ideally) or mess with camber too much.

18x9et43 Mich PS 235/40/18
18x11.5et35 315/30/18

thanks in advance!

Lazurus

If it were me, I'd go the extra .5 inch to a 12" on the rear. I also once ran a 9" in front but swapped it for the narrower 8.5 and think the OEM GT2 sized wheel and tire combination is the sweet spot. If you drive on the street in a reasonable manner I don't think you'll have inner liner rubbing issues with a wider wheel. The more extreme the driving conditions, the greater propensity for rubbing on the wider wheel obviously. Your tire size choices are time honored widely used, and I believe an improvement over the narrower OEM fitment.

Bernard IV

You're probably going to have to roll your fenders if you're going with 315. It's not a big deal at all, just buy the Chinese fender roller, works great.

krp220

thanks for the reply. What is your thinking behind going up to a 12” rather than the 11.5? I assumed that would help me avoid rubbing issues etc

Lazurus

The less width, the less chance for rubbing sure. My take is the wider wheel is better suited for the widebody stance and I imagine this helps explain the factory 996 GT2 sizing. I don't know if you'd experience any rubbing on a 12" rear, during "normal" street driving. I think it comes down to how and under what conditions you drive the car. If you're slamming corners in twisties than it might be an issue sure. If you're just doing straight line highway + speeds, then I think you'd be ok. All of that said, my fenders are rolled to give me that minimal added clearance and it helps. There's not a lot of "extra" room to work with in the wheel wells and I have experienced inner liner rubbing both with and without rolled fenders.

onyxeros

that spec is a pretty aggressive rear offset for a 11.5 wheel. I am going off of the gt2's 12in +45. I think you are in danger of potentially having to roll not because of your width but because of your offset and tire size.

powdrhound

Wider is always better from a performance standpoint as ideally you wanna stretch the tire a little bit instead of pinching it. I run 12.5" on a 300/680. On a 315/30 I'd run a 12" for sure. Porsche uses a 12" on a 305 on the 7GT3...

Lazurus

That's a cut and pasted post from my earlier post upthread.

Moderators. Bot alert.

krp220

this is ultimately the look i'm going for: (post 331)
https://rennlist.com/forums/996-foru...alking-23.html

and avoid this, where the tire angles in under the fender and into the wheel well

Bernard IV

The performance is actually a little bit better if the tire is stretched a bit on the rim.

QwikKotaTX

I think that has more to do with offset or spacers than the width of the tire.

Bernard IV

Oh he doesn't want like 2 degrees of camber in the rear. It does look a little bit like a stanced car.

powdrhound

If the tire doesn’t angle into the wheel well then you would get tire to fender contact under compression, aka rubbing…

To put in overly simple terms, in order to have full unobstructed suspension travel, the tire has to angle into the wheel well.

krp220

lol i'm not that dumb. this is not my first endeavor with wheel and tire fitment but wanted to get the insight from those that have the fitment i'm looking for. the wheel still moves in/under the wheel well in an arc so even if the sidewall is more square (i know it's not ideal for it to be completely square) i should avoid rubbing issues if' i'm not overly low or my offset is appropriate, right? i'm just trying to avoid an OVERLY angled tire look, and obtain a "fuller" fitment. the silver 996 turbo i pictured above has more of that than i would like, which is why i initially suggested an 11.5" wheel and a 315 tire, but TheDeckMan informed me he runs a 305/35 on a 12 so many thats they play?
not trying to split hairs here, but i'm hoping to achieve a certain look and i'm aware of the importance of having right tire diameter to avoid AWD issues. i also don't want to mess up the sizes on a custom forged wheel order $$$...

powdrhound

The reason the wheels on the silver car you posted look a little odd is due to the offset being way too “sunk in”. It would be a lot better with a 5 or 7mm spacer. With that said, a 12” wheel is appropriate for a 305 or 315 tire. From a performance perspective, you always wanna fit the widest wheel you can for a given tire size. On a 6TT/GT2 a 9/12 wheels are optimal for the typical 235/245 and 305/315 tire.