UstaB-GS549

Has anyone run a 315-17 on a 9.5" wide rim? I'm pretty sure the T1 guys put 315's on 10" rims up front.

rikhek

Numerous forum members have told me not to run a 305 on a 9.5, let alone a 315.

Rick

greendot

And the other side of the coin is that numerous forum members run 315's on 9.5 wheels, so I guess the choice is yours.

One factual data point I can tell you is that Lance Knupp found that he was faster with 295's on the front of his T-1 car than with 315's.

UstaB-GS549

Greendot:

Thanks for the good info.

If I had more money I probably would run 275's or 295's or just buy a set of CCW 10's & 11's, but my budget only allows for used tires and my old paid for GS 9.5 & 11 rims.

I feel better knowing that it has been done before.

I know some guys have run 315's on the 50mm offset wheels up front too. It's probably not optimum either, but hey I'm already running used 275 GS-CS up front with 315 Victoracer's in the rear. I'm sure someone would say that was a bad idea too, but my SOP says it feels OK.

wtknght1

I used to shoe horn 315s on 9.5 rims and it will work...but I'd go with 275s or 295s if I were you. If you're just doing DE stuff, it won't really matter, but you'll have to experiment to see which combination is actually faster. What you may gain in grip using the 315s up front, you may lose in rolling and aero resistance. I still like the 275s up front on my T1 car. The Kumhos are sticky enough to do that.

UstaB-GS549

I need for you to convince all your T1 buddies that 275's are the way to go, so I have a endless supply of cheap scuffs readily available from multiple sources.

vms4evr

Yeah what he said!!!

Rx7Rob

Check with the tire manufacturer. They all list recommended rim widths.

UstaB-GS549

I know what the "recommended" widths are and probably should have prefaced my question with that statement. Goodyear has a recommended minimum of 10" while Kumho & Hoosier recommend 10.5" as the minimum.

I was looking for practical reasons and personal experiences from people that have done this with either good or bad results.

BuckeyeZ06

If you are speaking about the same Lance Knupp I am, he's not very fast. He has trouble getting out of the way of T2 cars.

VetteDrmr

One more data point: my experience has been (along with others that have tried the same setup) that when you run a C5 square (in this case, 315s front and rear) the car will start oversteering. Admittedly you might have more cornering speed before you start oversteering, but depending on what you are doing this may be a bad thing.

This past weekend at a medium speed event I beat a driver I consider to be better than myself (I celebrated mightily!!! ).

His setup: stock '99 FRC, running 315 GY GSCS tires all around
Mine: mainly stock '00 FRC, running Toyo RA-1 275s front, Victoracer V700 315s rear. My car was well balanced during a high speed sweeper (clicking the rev limiter in 3rd on corner exit); his kept having the rear end getting loose and he'd back off. We were both having power oversteer on the slower corner exits, but again my car was better balanced than his. So he was able to get into the corner faster then me, but I was able to get the power down sooner on exit.

And UstaB, I'm SO with you on the used stuff!!!! My motto: "I may not be quickest, but I'm cheap!"

HTH, and have a good one,
Mike