Buck

I had my first autocross on the 04 autox tire and I must say it was impressive. Even giving up some tire size, very limited sizes so far, the car stuck and had much crisper turn-in and mid corner feedback than the Victoracers I've been running. I've been running 255/40-17 Kumhos all around on 8" and 10" wheels. I now have 245/40-17 Hoosiers on the same wheels. It's a little shorter tire so it helps with grunt out of lower rpm 2nd gear corners and I didn't notice any lack of traction giving up .5" width in the rear. This setup is a lot faster. I got FTD at the Peachstate PCA autox this past weekend first time out. After the fourth run I still realized there was a lot more left. I'm looking forward to the SCCA Divisionals in two weeks on the same lot.

If you're looking for the ultimate autox tire this may be it. The new Kumho 710 is getting great reviews from autoxers but they are being recalled and will be replaced with a new tire in about 60 days. SCCA banned it from competition until the recall is complete.

Buck

nile13

Buck, I think 255 on the front is pretty insane in my opinion. No wonder you felt crisper turn-in with narrower tires (provided that 245 Hoosier are actuually narrower than 255 Kumhos). But why the same width all around?

kary993

You put a 255 on an 8" wheel? How does that work out in terms of wear?

Buck

Several national level autocrossers have told me you can never have too much rubber on the front. That's where all the real action in autocross happens.

I've always run my 911 autox setup with the same size all around. My '87 Carrera ran 225/50-15's all around and was a great autcrosser. The 993 is very well balanced now with the current shock and sway bar settings and 245/40's all around. The 8" wheels in the front actually give you about an inch less rubber than the 10's in the rear do. If I ever change wheels I will go to 9's in the front because "you can never have too much rubber up front".

The Boxster S that came in 2nd at the SCCA Nationals two years in Super Stock had 245/40's all around. Only one of the 43 Z06 Vettes out ran him. He also believes in a lot of rubber up front.

Maybe it's my driving style but I can always seem to make it push so I want all the grip up front I can get. More grip in the front means you can get on the gas sooner in the corner. Porsche did a great job of taming the 911 tail with the 993 suspension and it's taken a lot of work to get it to want to stay turned in under acceleration.

The other tip I get is autox is a series of drag races. Whoever gets the hole shot out of each corner is going to win. Being able to get on the gas early is important to being able to win all the drag races in one run. If you can't get on the gas because the car is pushing you just got beat by a hole shot in that corner.

To finally answer your question why? ... seems to work pretty well so I've always done it.

Buck

Buck

Kary, the wear was actually very good. I had one set of fronts last through two sets of rears.

rcwelch

Buck...as a past National SCCA Solo II champion, I have to agree with your thoughts on up front rubber and application of the throttle EARLY...Good Luck to you!

nile13

Buck, I don't disagree with your thoughts, but I think you're giving up a lot of turn-in crispness with these front tires. That was the gist of my comment.
I shouldn't be talking, I'm running a Miata on 225 Hoosiers this year.

kary993

Buck, I was not disputing more rubber up front. I was talking about correct fitment of that size tire on a small wheel. The tire does not perform as it should when it is not supported correctly. Just a thought.

BTW, I go through three sets of rears to one set of fronts for my 993 on big tracks.

loudes13

turn in crispness vs. ultimate grip

I personally would take grip anytime over steering feel. Obviuosly it's a compromise, but 245's on an 8" rim doesn't sound like too much. I remember running 265/45/16's on 16x8's with success. Heck my Honda ITB car runs hoosier 225/45/13's on 13x6 rims. They are tough to mount, but they work well!