billd17

I am about to replace all four tires on my RSA and was wondering what the current wisdom is on brands and sizes. I'm looking for a street tire (DOT treadwear of 100 or better) that's suitable for autocross and daily driving - wet or dry. The last time I looked, the Bridgestone S03 was the best tire of this class available. Have things changed?

As for sizes, I currently have 205/50-17 and 255/40-17 tires front and back on factory 17" wheels. I am considering going to 225 in front and reducing aspect ratio - say 225/40-17 and 255/40-17. Has anyone tried these sizes? How do they work? Do the wider tires fit OK in front?

ian c - u.k

you want a smaller aspect on the wider rears

BGLeduc

Well, a friendly piece of advice.

Bite the bullet, and buy a second set of wheels with some real autocross tires. Those S03's are fine tires, but do you really want to look at how chewed up they are going to get if you autocross 'em?

And they aren't really cheap either.

A set of Kumho V-Racers can be driven to and from the track without fear that they are going to be punctured. While I would not want to drive them in a monsoon, if they are unshaved, they will get you home and back even in the wet, as long as you use a degree of common sense.

OK, I know thats not what you asked, but I just hate to see what autocross does to pricey street tires. And a set of butt ugly D90's are dirt cheap (well, dirt cheap in a Porsche context).

And as a bonus, I would bet you would quicker on the Kumhos in an autocross too!

BGL

Bill Gregory

Bill,

Agree with Ian and BGL - 225x45 and 255x40 is a good combination which will help reduce understeer. A second set of rims is the way to go, and a tire like the Kumho Victoracers (a price performer in 'r' compound tires) or Yoko A032's or there are others which are all good 'r' compound tires that can be driven on the street.

billd17

Thanks for the advice on "R" compound vs. street tires. For now I'm going to stick with street tires since I'm running in a class that does not allow "R" tires.

Any advice on other street tires as alternatives to the S03s?

It sounds like 225/45, 250/40 are the right sizes.

DJF1

Michelin Pilot Sport RIB. Truly a great tire.

joey bagadonuts

I autocross on MPSC's and they're not bad as long as you remember to run at hot pressures, 34-36 psi.

As for street tires, the "hot" autox options include Falken Azenis Sport and BFG g-Force T/A KD's. The Falkens only come in 225/45/17 and 245/45/17's but that's probably not a bad setup for autocrossing. Other low-cost options include the Yoko AVS ES100 and Kumho Ecsta MX. Pricier choices would be the S-03, Goodyear Eagle F1 GSD3 and Toyo Proxes T1-S.

JoeW

I think you slipped on a key with that, didn't you: 255 on the rear will work.

Locally, SCCA class winners run Hoosier and use a tire trailer to get back & forth. They swear by them but they are an "R" tire, again, and have some disadvantages (cost, durability) that makes them primarily for the podium crowd. Joe W

AsianBond

I'm about to switch from my SO2 to the new Michelin Pilot Sport Cup tires which are a R compound, there's another thread on this site that has very favorable reviews about them. Read that there is some F1 technology in them.

Quick question guys, I'm running 215/45-17 SO2 in the fronts now, the MPSC only comes in 225/45/17, what are the effects if I use the larger size? I'm trying to avoid the dreaded heavy steering feel that i had in my 993 with 18's.

joey bagadonuts

I think any R compound will feel significantly heavier than a street tire at low speeds. I've run the Kumho Victoracers as well as the MPSC's on public roads and the MPSC's feel more like a street tire. The Victo's were better in the rain, however.

Obviously, the C4 rack has a little more weight than a C2, but in a relative comparison, the R's definitely feel heavier than a street tire.

fore!

I'm on my second set of khomo ectsa's. I run 215 on the front and 255 on the back and have no complaints. I'd run 225's if i had power in the steering dept.

Ditto - with the other guys. If I do get back to the track it'll be with tires for the track.