Superwide Rear Tires: 315

Superwide Rear Tires: 315

I am in the midst of "fitting" 17 x 11 in the rear with 315/35/17 Kuhmo Victoracers. I say fitting because when I first bolted the wheels to the hub THE TIRE WOULD NOT MOVE !

I would not recommend this setup for anything but track because there is just not enough clearance for any kind of debris.

I have finished installing one side after a few hours of persuasion and I believe that the end results will be great. BUT ! This is not a simple bolt on and NOT for the faint of heart.

Also the fronts I am running are 9.5 rims and not the 10s. You can still mount a 275/40/17 on the 9.5 rim and you should not run into clearance problems. If you are looking for an easy install that you could drive on the street I would recommend the 9.5 rim and 275s all the way around. That is the set up that Kim Crumb has used in the past with great success.

E-mail me if you decide to go LARGE and I can give you some hints as to where to apply the BIG HAMMER.

Ken Bigham
85 S With really evil wide wheels and tires.

Mine fit fine, Tom. Yes, they are very tight. But with a little patience, I am succesfully running both Kuhmos and Yokohama AO 32s at the track and on the street. I find the Yokos are a bit better for the street, though they have a howl that takes some getting used to. 17x11 and 17x10 front(I think) 315x35 r and 275x40 fronts. I have a set of Knessis and a set of HREs, and I had to make some spacers, (.20" worked on the Kuhmos on one set of wheels, .25" on the other, etc. etc.) You just have to fit them carefully and keep track of which spacers work with which tires and wheels. I will be trying some Hoosiers next, and I am sure they will take a different combo.
I had to force the fenders out a bit at the rear. I did this with a piece of gray electrical conduit. You start it into the wheel well between the tire and body, then roll the car to force it through, which deflects the fenders just enough. Not for the faint of heart, but it worked for me.
You will love the rubber at the track. You will also find the car loves to hunt the ruts on our wonderful Oregon freeways, with the wide rubber. Trade-offs.
Michlen also makes(or made) a 285 MXX3 Pilot, which I have used and use for open road races. This is a better tire for the street, but not so good at the track.
Don Hanson

As I have posed a few times in the past, I run 9.5 and 11's with 315's and 275's. However, before this tire combination, I ran 275's and 255's. This worked the best as no modifications were needed on the fenders, except some slight rolling with a wood baseball bat. (just to fold the lip of the inner fenderwell) However, 315's worked with some more rolling, until I had my first track day with that set up. IT RUBBED SO BAD that it pushed the tire off the rim!! Not only was it rubbing the outer fender wall, it was rubbing on the fuel lines on the inside as well as the frame.. (with my spacers removed) With the spacers on (20mm stock) the 315 had no chance of fitting. That's when I broke out my 10 pound mallet and started going to town. Looked lousy for a few events until a bodyshop cleaned it up!!! Now it looks great.

So, the moral of the story is the 9.5" fronts and 11" rears work with the 255's and 275's with little trouble. 315's can be a challenge, and up front the 275s need some very careful fender rolling as the front fender is aluminum and is very brittle.

Mark Kibort
928 5 liter part euro '84 with 85 LS transmission, 82 euro heads and cams,
85 euro intake, 85 block, 93 GTS mirrors and wing to come. 2800lbs,
all bright red!

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