greger

I'm driving a stock suspension, 911SC Targa in DE events. The alignment specs are set for track but I am getting a very regularly spaced cupping wear pattern on the outer shoulders on my rear RA-1's (245/45ZR16 mounted on 9x16 Fuchs). The front tires don't show this pattern. Note that the front negative camber is visibly greater than the rear camber. Might this lack of (or less) neg camber be the culprit?

I've checked with one other Porsche/RA-1 driver and have found the same wear patterns on his Toyos. Anyone else having similar problems? Any advice for correcting this problem? I'm running F-26lb/R-29lb cold with my Toyos.

Greger

Richard C2S

Greger,

The rear should have more negative camber than the front. Usually by half a degree. If you are correct that the front neg camber is greater than the rear, your alignment is not set properly, particularly for the track. I suspect that is why you are getting the cupping on the outer edges of the rear tires. Check with Toyo. They, or their website, will tell you how much neg camber their tires like.

Trucho-951

Could be too much rear toe-in. I was running 1/8" toe-out in my 86' 951 and never had that problem, this year had my alignment changed to 1/8" toe-in (for better stability) and my rear RA-1's started cuping at the outer shoulder. I think I'm gonna try 0" toe, if that's not enough, then I will return to 1/8" toe-out.