Knight

TCS unfortunately SS are not available in WB sizes.

PiB993

Not to hijack but related I think, if someone is getting new wheels(rims?) for a Turbo should they stray from the stock dimensions for performance and tire selection - assuming ROW ride height and no rolled fenders?

LexVan

Street or track or autocross? What wheels (some are fine, some look stretched....for example 996 hollow twists work really well with bigger rubber because they are 1/2 wider [IIRC] than 993 hollows).

Yes better tire selection when you up size +1. Cgfen listed the sizes. Work great. Look great/better in the wheel well. No fitment issues with a ROW ride height and standard alignment. No issues with the AWD and viscous coupler.

Basal Skull

IMHO - I think stock sizes work well and look good, and are fine for the street with modern rubber. Going up in size is only mostly for looks and you aren't going to be able to exploit (nor should you) the limits on the street. Also when increasing size (whether just tires or wheel combo), you will almost always increase unsprung weight which could decrease performance (particularly in a NA car). If you are finding that you are getting greasy towards the end of your track session or find you can't take the same lines as those faster than you with similar cars at the track, then increasing sizes is one of the things to try. Tires make a big difference at the track, not that much for me on the street as I get nowhere near adhesion limits.

DiegoR

Hopefully is not "so OT" but I'm looking to get a new set of tires. I'm undecided what size go but also depends of the manufacturer if does offer such sizes.

Running 18x8 front and 18x11 at the back (996 TT wheels) I was looking to get the Direzza Z II Star Spec (great value for the money IMO). However I'm undecided if go with 285/30/18 or 295/30/18 for rear as these wheels are 1" wider over the turbo wheels of the 993, however front are same width.

Go 225/40 on 18x8 & 285/30 on 18x11

or

Go 235/40 on 18x8 & 295/30 on 18x11 (I don't know if 235 will look "goofy" or fatty in a 8" wheel)

Any suggestions?

LexVan

Go 235/40 on 18x8 & 295/30 on 18x11

Basal Skull

The other thing with going wider is that you will also increase tram tracking at speed depending on your road conditions which isn't all that fun.. Just things to consider.

Knight

What tires are you planning on using? Some are more stretched than others, example Sumis and HKs are generally slimmer tires.

Your are right 235s on a 8" it will look not right on most tires. I'm on that setup and run 225/295 HK, which is the factory spec for 996TT too. Proportionally front and rear look balanced correctly.

DiegoR

Knight, mostly EXTREME PERFORMANCE SUMMER TIRES if that tittle does help, basically a street car with ocasional trackdays for my C2 project.

I'm bit concerned about how aesthetics would look my tire/wheel combo and I like "square" looking wheel/tire combo (looking from the back or front that the tire is not streched too much to inwards or outwards of the wheel edge and also not much height as SUV profiles).

So, one thing that worry me if I go with 225/40 front and jump from 285/30 to 295/30 because the extra1" of the 996 wheels, it could result in a "push" behavior because only increasing the rear width and have a more unbalance between the front and rear axles.

thoughts?

Vince964T

For my own limited experience (track junky) I feel you do run the risk of increased understeer.

Depends on a whole lot of other factors of course and may be you have some margin on sways or camber to dial it back.

A good starting Point is if you are already understeering then you can be pretty sure of what will happen by increasing rear sizes only and you ll have to work on the set up.

PiB993

I meant E88's which are pretty customizable for sizes?

Mainly street. 99%

AC/911's

235's are taller, as your rears wear they'll increase a little too, 295 & 225, cheaper brands tend to spec thinner & shorter, Tire rack is good for seeing exact specs/ IMO.

DiegoR

Yes, I have been looking in tirerack for models and size offering. I might go with factory turbo size tires hopefully the 285 won't look bit skinny in a 11" rim width.

Thanks all for their suggestions/help.

Knight

I should've also mentioned I tried that combo before and the rears ended up looking much too stretched vs the front with Bridgestone SO2s at the time.

Mike J

The specific rims can also visually change the look of the tire, such as a deeper dished rim vs say a RUF which is very flat faced.

Too bad there is not a place where you can swap tires on various rims on your car to find that perfect - for you - look and fit.

Cheers,

Mike