Biofuel

I am trying to price wheels and tires for a potential 928 purchase (it would be either a '91 GT or an '87 S4). I would like to put at least 295s on the rear and even 315s if possible so I probably need 10" or 10.5" rear wheels. I am really not bent on 17" or 18" rims - I could go either way. I am just not real sure where to start searching in terms of; available wheels in the right sizes, appropriate offsets for fitment, technical staff that really knows what they are talking about for help with the purchase, etc.

I like the looks of the 1994 911 3.6 Turbo wheel, and also the Turbo Twist. Carrera III wheels are ok, too. However, I would really like to get a bit of a deep dish look in the rear and the Turbo Twist and Carrera III wheels don't really have that. Also, what is the best size to match up front?

Any input would be very much appreciated. thanks.

IcemanG17

A general rule regarding tire width to rim width is to use a .86 ratio....meaning take the eidth of the rim in mm and divide by .86 and that will give you the largest tire you should run on that width rim...if you exceed the .86 ratio then the sidewall performance gets goofy and the tire may not perform correctly at the limit....so for a 10" rim the limit is a 295 tire.... 11" could do a 325 etc....

largecar379

this is what I run:

235/35/19 on a 19 x 8 et 57mm

315/25/19 on a 19 x 11 et 67mm

19's are not for everyone (some folks don't like the short sidewall), but you can do similar things in 18's as well.


check with Carlos at Wheel Dynamics or see his eBay ads---a wide variety to be had from him and many examples on his website for you to look at, and he is very knowledgeable about what fits and what doesn't.......

Hope this helps---

Russ

largecar379

a further note:

due to the 928 rear axle ( and front for that matter) being offset to the outside as far as it is, you may not find a "deep dish" to your liking unless you have wider fenders such as those on the GTS.

front wheel widths are generally limited to 8 inches (I have seen some with 9.5's), but if you want to hack up a fender you can go to 10's. I am told that you can run as big as 245/35/18 on an 18 X 10 wheel up front, but it may require fender hacking and spacers.....IIRC the only Porsche offering in 19 X 10 has the wrong offset to be used on the front.

check Louie Ott's website as well, and you will see what 12 inches wide looks like with a spacer to get an even wider track----of course, he has installed his Nizzazzz fenders to cover the wider stance. A great look from behind.

there are sometimes tire/wheel sets for sale below $1K (used) but they are generally 18 inch and smaller diameter.

if you really want to go big with three piece modular wheels, you can count on very big $$$

another thing you should be concerned about is tire diameter---whatever you choose, you should try to stay with the same tire diameter as those that come from the factory.

hope this helps--

--Russ

Biofuel

Brian - thank you.
Russ - I couldn't find anything under "Wheel Dynamics." Is there another name I can Google?

I did find Wheel Enhancements and that looks like a pretty good web site. No prices, but I can call during the week.

Biofuel

Russ - any ideas on where I can find info on factory wheel/tire combo diameter?

Biofuel

Wow - I just saw the pic, Russ - that looks really great!

largecar379

wheel/tire sizes for:

S4 ---7x16, 8x16 225/50/16, 245/45/16

GT---7.5x16, 9x16 225/50/16, 245/45/16

approximately 25.5 inches in diameter

go to eBay, 928 parts, and search all 7 pages----you will find Wheel Dynamics

---Russ

morganabowen

Biofuel,
Try www.wheeldynamics.com. I have done business with Carlos from Wheel Dynamics in the past, and my experience has always been very favorable. Good luck on your search

largecar379

928 Specialists website does have a chart listing the original tire/wheel sizes for all models.

and yes---what I said.....wheel dynamics is the deal.

Happy hunting!

--Russ

edco

Wheel Dynamics also has an application guild listed

http://www.wheeldynamics.net/appguide.html

Biofuel

Found the Wheel Dynamics site. Thanks, guys. Great site. I have to say the Wheel Enhancements site is pretty good, too. Only down side - no prices!