Same size wheels front and rear?
 

Just wondering if anyone has done this? Advantages, disadvantages? I have 7/16Rear,6/16Front now and was thinking of putting 7's on the front or 8's all the way around. Thanks for your thoughts>

Oh and I did search but could not find anything on this topic.

I ran 7s all around on my RoW cab and had no problems with it. The left front tire scrubbed once in a while as it was set to RoW height, but I got used to it. Not sure if 8's will fit well in the fronts unless you get 951 8s.

wheel & tire width are part of the tuning for specific handling characteristics.
narrower fronts or wider rears adds to understeer, the opposite reduces understeer

7ET23 8 ET10.6was an oem fitment w/ 205/225 tires

8ET23.3 front(951 8s) has been done but it's extremely tight wrt the lips. 8 ET25-31 is much preferred. Most people w/ SC/Carrera flares would want a 9 ET15 w/ a 245/45 tire in back.

being a little tight on the money, I run stock 7s up front with Euromeister 8s on the rear. Also, I run 225/50/16 up front and 245/45/16 out back. I had to roll the lips up front to make this work. my car is a beat up track whore

I run 15x7's on all 4 corners on my track car. May not be ideal, but at my skill level I do not have any problems. The benefit is I can rotate tires front to rear for even wear. I actually have (6) 15x7's. I put the best two on the rear, next best two on front, and the last two as spares. Repeat for every track event.

Seymore,

How will you be using your baby? I believe that and budget will determine your needs.

I simply a around towner at low to moderate speed then 7's all around will be fine as some have stated.

If you want optimal performance then you need to stagger her.

Jim

8's won't fit on the front of a 911 unless they are the 951 offset 8's. i find a 1" wheel size (20mm tire size) difference to be ideal for '74-'89 911's. i've tried same size all around and the car is a bit too tail happy for my liking. i've tried 7's in front and 9's in the rear (205's and 245's) and it just plows, too much understeer. all of this assumes a stock suspension setup. once you start playing with larger t-bars and adjustable sways, you can make it do whatever you want.

my favorite setup is 951 8's in front, and 930 9's in rear with 225's and 245's. this is what i use on my track car.

This is an important point to keep in mind. Rim and tire size are only one of the many factors in suspension setup that effect handling balance. None of the early production 911 models were delivered from the factory with any F/R rim-width stagger until the '73RS, which was the first to receive 7" rear rims paired with 6" fronts. The square tire/rim setups in the early cars were balanced with torsion bar, ARB, and alignment settings as well as possible for road-going use, though the SWB cars developed a reputation for oversteer that led to the lengthening of the wheelbase in 1969.

The intended use of the car is key, though, as at higher speeds, with the front wheels doing less steering effort, the car transitions more towards oversteer with a square setup, and the factory fitted wider rear wheels and tires on the 911 race cars as early as the '67 911R for high-speed use. For slow, tight corners, such as in autocross events, a square setup might offer a perfectly acceptable balance, while on a big, fast track, the same setup could result in sphincter-tightening oversteer. I have run 7x15 rims w/ 205 tires on all four corners when autocrossing my SWB cars for years, and they work fine with the correct ARBs and alignment settings, but at a track like Willow Springs, the "fastest road in the West," it makes for a wild ride! I would much rather have a more suitable big-track weapon with large F/R stagger there. The trade-off for this high-speed stability is low-speed push, so you need to decide which you would rather deal with and have to "drive around" more often. Having adjustable sways and shocks can only go so far in mitigating this low-speed/high-speed handling balance change. If most of your driving is done on the street, even in a "spirited" manner, with max. cornering speeds usually in the 55-75 mph range, a satisfactory square setup can be achieved easily, and has the aforementioned advantage of being able to rotate tires front to rear to even out wear.

HTH,
TT

Hmmmmm. Did you search "stagger" in the auto-cross section?

'Cause you might have found this:

http://forums.pelicanparts.com/porsche-autocross-track-racing/515411-911-understeer-issues-auto-cross-long.html?highlight=stagger

There are some pretty interesting issues raised by some real experts (not me) around page 3.

And this:

http://forums.pelicanparts.com/porsche-autocross-track-racing/386742-optimum-wheel-tire-stagger-auto-cross.html?highlight=stagger


Have fun.

I ran 4 7" cookies with r rubber (225/50/15) at the track for 2 days. AWESOME!! I was on a stock susp. then and the car was soooo easy to drive. A little trail brake and set the car for the corner. Then just use the right foot to steer it around and zoom away on exit. My best track day experience to date. It was not too tail happy and didn't under steer. A great benefit was being able to rotate tires between sessions so each tire got a break and wore very evenly.

enjoy!