bowmanm98

I had 1.9F and 2.1R and my street tires were ruined very quickly. I think it's too much for a street car. Go with something like 1F and 1.5R

schvetkaaks

Chris - I know that most of the mess is marbles, but check the edges of the tread blocks - they are worn in such a way that it looks like when you break off a dry cheese or something - not even at all. See the first picture...

karlooz

how do you corner balance x73s? i thought they are fixed strut type not adjustable coil overs.

TheOtherEric

I would agree with this. If it were a 993, I'd say 1.5F and 1.5 R. Just watch for wear on the outside edges of your MPSC's but I think you should be fine.

38D

I have seen that MPSCs from too low a pressure...similar to the old "groove of doom" on the BFG R1s.

I start at 28F/26R and typically have to bleed off pressure during the day. I shoot for 32F/34R hot all the way around.

cgomez

Palting, as I mentioned in the other related post ("Corded PS2s") you really need more than -1.5 camber up front. I would say at least -2 for the way we drive at the track.

My 997S is maxed out at -0.8, and I'm probably going to do a simple mod done by many GT3 owners which is to "slot" the mounting holes on the strut towers.
I don't really want to lower my car for practical purposes (getiin in and out of drveways, winter driving in snow, etc.) and I find the OEM suspension the perfect balance for street and some track driving (6-8 DE days/year as my real track car is a Lotus Elise).

From the way it seems you drive (and the way I drive) I don't think you will ever get premature wear on the inside of the tires. So go for that extra much needed camber. Most likely, as it happens to me, you will wear out the whole tire before getting enough street miles for this to be material.
Also, extreme wear of the inside shoulder is mostly caused by excessive toe in instead of too much neg camber.

karlooz

the gt3 guys also "flip" the spring tops to get more camber. i just did it on my setup. instead of slotting the 3 mounting holes i just elongated the big hole in the middle. i was able to get -3degrees camber.

you can get camber plates and do the same.

Bob Rouleau

Palting - I've been driving 911's on track for 15 years or so. You need to compromise. On my 993 I used neg 2 front and neg 2.3 rear which worked fairly well on track (shoulders lasted 2 x longer) without shortening the on road life too much (inside shoulder wear). I drove the 993 on the street a fair amount and lived with the compromise. My GT3 is more a track car and I have neg 2.5 in front and neg 2.4 camber in back. I wear my tires out on the track long before they are a problem on the street so, track performance is the priority. Unless it is raining like hell, I leave the Cup tires on all the time, the added wear on the street is inconsequential since they will die of heat cycling before the tread is worn. Dunno if this helps, but there is no doubt that with your alignment as it is now, you will forever wear out the shoulder of the tire prematurely. At the very least you should go for neg 1.5 negative in front and neg 2 in back. That's the factory alignment for the old RS America and it is safe on the street.

Best,

cgomez

Do you flip upside down or swap left-right?
Do you know if this can be done or is it the same part in a 997S?

Any further guidance on this is appreciated.

schvetkaaks

38D, I was running 33-34/36 hot - higher than what you have listed. I guess I could try to bring up the fronts a bit more.

Bob Rouleau

schvetkaaks - 34-36 hot for Cups is in the ball park. On a GT3 I run 32-34 hot with tread temps around 175 deg F measured after the cool down lap. Probably around 185-190 before coolinig off for a couple of minutes. That's pretty much where Michelin says they should be.

Rgds,

schvetkaaks

Bob - then why am I getting that wear pattern on the fronts? Camber? I'm low in front, only .5 degrees negative so far.

hdemas

I'd agree with what Bob has said.

Palting, looking at your tire the first thing I thought was not enough camber. I'd suggest running -2.5 front and -2.0 rear based on my experience with the 993...this should provide a reasonable compromise street/track. Could do -2.0 front and -1.5 rear but would then still definitely wear the outside of the MPSC too fast. Use zero toe in the front and only a bit of toe in at the rear which will both improve wear both on/off track and . Front of the car is light so tire wear on the street in front won't be all that bad. Rear tire wear won't be great but this is the only way to improve the tire wear on the MPSCs. Car will be significantly faster with more negative camber. Also, you should try lowering your rear tire pressure closer to 34-36 instead of 40.

schvetkaaks...is that the front or rear tire you pictured. From my experience with the boxster I used to have I'd say your -0.5 degrees front is way too little...should probably try to get that up to -2.0 degrees. The -2.0 degrees rear is in the right range.

TT Surgeon

I ran -1.5 fr and -2 rear, went thru my street tires in short order(x73). Went back to -1fr and -1.5 rear, my wear at pocono was pretty even, but I was a little high on pressure( 37/39) and the rears seemed to wear pretty damn fast.

Palting

Thanks for the replies and recommendations, everyone.

At my current settings, the front and rears have been equally wearing out the outside of the front and rears. I'll probably add equal amounts of negative camber front and rear. I'm headed to Watkins in a few weeks. Thats a 4-5 hour drive on my street tires (PS2), and a 3 day DE on the MPSC's. Worst thing that can happen is I'll wear out the inside on the PS2's, which I can't wait to replace anyway since the outside shoulder is worn, and the MPSC's will wear out more evenly. Or, I've hit the right compromise and everything will be perfect .

Thanks again. I'll keep you all updated