Fishey

The 993 is currently running 205's in the front.
The car seems to understeer far to much....
Anyone know if you can run 225's front and what diffrence it make's?

ApexL8

You can run 225s without any rubbing. 17" wheel right?

Check out my tire size calculator:
Tirecalc.html

A 225/45-17 is about 0.4% smaller than a 205/50-17.

My preferred method of reducing understeer is PSS-9s and RS swaybars, front bar full soft, rear bar in the middle.

Viken

225/45-17 is fine in front. You might want to consider using a 7.5" wheel to make it even more effective.

Mark in Baltimore

Fishey,

I'm about to go to MPSC's in a 225/18 front and 265/18 rear with Fikse FM-10's (correct offset, of course.) I was told I shouldn't have any rubbing problems, even with my very lowered and PSS-9-equipped car. I actually would like to go to a 235 in front but Michelin doesn't make that size.

JPS

I went with 225s in front, looked at the tire size calc, etc. For my tires (RE 750s) the 225s were actually a better overall diameter match to the 255 rears, so I was pretty happy, and the understeer is actually quite significantly less in Auto X...I have only 1 track day so can't speak to that, and on the street, well, who knows...I wore the last set down to about nothing, so hard to say the improvement is from size or just new tires.

I really stressed over how it would look and all that...you really can't tell the difference visually, and the little bit you can I think actually fills up the well a bit better.

Mark in Baltimore

Kim - Thanks for the info. I actually just stumbled across the track tire thread over on the 993 Turbo board and read that 235's are coming soon.

STLPCA

Fishey
I've run 225x17 MXX3 fronts on stock 7" Cups this DE season. My car is mildly lowered. Very noticeable decrease in understeer & no rubbing. Many here have used that size for years. There's no reason I can think of not to use 225.

Fishey

stock rim's for a 1995 c2 (the 17" cups)
(I think there 7" on front right?)
Also I head on the 995 there is something you need to do to mount 18" rims..... What would this be?

Mark in Baltimore

Do you mean the steering rack brace?

Fishey

I guess? I don't really know.....

I remember hearing something about a modification you need to do to 1995's to mount 18's... I dont understand the need for the brace? maybe you can help me understand.

Mark in Baltimore

Fishey,

There are a bunch of threads on it. Try this link.

As per some Porsche service bulletin, some 993's with certain VIN's require it while others don't. I was told that even if you don't have it, you should install it if you're running 17" or 18" wheels on the track. I just bought one at Crescent Porsche (800-966-7222) for about $34, not including shipping or the screws.

Part # for steering rack brace: 993-347-131-02

Part # for screws (2 needed): 999-218-103-09

Viken

Yes, the stock rims are 7" and 9". You can also get a 7.5" of the same stule if you are interested.

Matt Vaughan

Hey Kim, any idea what the overall diameter will be? IOW, a good match for our 285/30's?

Viken

235-40-18: 25.4"
285-30-18: 24.7"

Matt Vaughan

Hmm. After I posted I checked the Michelin site. (Why did I not think of this before?) They don't list the 235, but do show the 285 as 25.1.

Viken, where'd you get your specs?