Marc Shaw

Hello all,

With the demise of the 17" MPSC, I am moving to 18" rims and tires for this track season. I drive a 964 C4 aligned to Euro RS spec except 5 mm higher front and rear and -2.0 degrees and -2.5 degrees camber front and rear.

I already have 2 sets of 18" MY02 5-spoke rims (8" and 10" wide), one with a set of MPSC tires mounted (265/35 and 225/40). I have not used these on the track yet. The other set has no tires on it yet and I want Hoosier R6's but I am unsure of the size to order.

I have a third set of 18" MY02 5-spoke rims with the same size MPS2 tires mounted. They fit well for street use (rims have ET 50 front and ET65 rear so no spacer is needed in the front and I use a 21 mm spacer in the rear).

My question is the size of Hoosier R6 tires I should order for the other set of 18" rims that I have.

I measured the MPSC tires on the 18" rims and they are 9.25" wide on the front and 11.25" wide on the rear (lay the tire on it's side, put a straight edge across the tire and measure down to the floor to get the max tire width).

It seems to me that, based on the info on tire widths I can get from the Hoosier and Michelin web sites, my best bet is a set of 225/40 for the front (web site says section width is 9.5" on an 8" rim) and 275/35 for the rear (web site says section width is 10.7" on a 9.5" rim). Once I mount the rears on a 10" (rather than a 9.5" rim), I figure it will be about 11" wide.

Does my logic seem accurate? Am I reading the Hoosier literature right? Can I really squeeze 225/40 and 275/35 tires (which seem huge) under my rolled fenders (with a factory flattened oil line)? Anyone running this combo on the track (not just street) and having any issues?

Sorry for the long post but I wanted to include all details.

Thanks for any and all help.

Marc

Gary R.

Mark, I believe all my friends running F (and G) Class 964's are running 285/35's in the rear and 245/35 up front, not sure of the rim widths. I ran 275/35 and 245/35 on 8&9" 18" CCWs for years on my SC, lots of camber but with the fenders rolled no rubbing.

I'll PM Dan R., his is an RS America (Stock G) but has the same body/suspension as you..

Chris M.

245/35 front and 275/35 rear. There are LOTS of pre-964 cars racing out there with the 245/40 x 17 up front and it is listed as wider than the 245/35 x 18.

Gary R.

I think your right Chris, I ran most of last year on Wayne-O's cast offs and they were 275 and 245 18's... Maybe it was just Dan R's car that ran 285's.. You going to get that thing running in time for Limerock?

Bill Verburg

Baron was running 245/35 and 275/35 R6 on the MY02996 wheels. He was ungodly fast w/ that setup.

Gary R.

Only reason I remember someone running 285's was that it pissed me off when going through the scrap pile in front of Dan's shop for my "new" race tires..

Marc Shaw

Thanks guys - I'll order up some new tires and be all ready for ORP.

Marc

swftiii

Sounds like you have already made a decision, but following is what I use:

Wheels:
BBS - RS GT (2 sets)
F/R - 18”, 8/9.5 (offsets: 50/48)

Tires:
MPSC(F/R) 225/40/18 / 265/35/18
Width - 9.2”/10.9”
TRY 235/40/18 – 9.5” Width - so should fit

Hoosier(F/R) 225/40/18 / 275/35/18
Width - 9.5”/10.7”

Marc Shaw

Skip - thanks for the input.

I thought I had a consensus but it appears you have 225 Hoosiers that are about as wide as my MPSC's so I wonder if I'll have rubbing issues with 245's on the front.

Marc

swftiii

I find the fit up front tight, but thre is a little play. The rears are tighter and there is no extra width available with my alignment.

I'm not sure of the height of my car, but it is about as low as it can go without rubbing through the wheel liners - already wasted a few of those on the driver side. Since yours is probably sitting up a bit higher than mine, you may have a bit more clearance for the 245s in the front.

Good luck with the fitment.

-Skip

Carrera51

I would confirm with Dan R what he has on his MY02 wheels and then do the same.

Marc Shaw

I sent him a pm too, thanks.

Marc

DanR

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