RS 197

This may be a repeat question but my search came up empty.

997 GT3. 5500 miles. Tires are o.k. on the outside but cord showing through the inside. My race mechanic says the wear pattern has the look of a tire that is under inflated. His advice is to run 40 lbs in the rear and 36 in the front. Any one experiment with this? I just set the lbs, I have a speed run on the agenda for the way home.

Any input from the pro's would be great.

mooty

if you aren't tracking it, only corded inside, you have too much camber.
also depends on the pattern of the corded patch, you many have too much toe.

36/40psi sounds too high. rocommended is 29/33 iirc.

PogueMoHone

That's the cold temperature. Based upon my experiences I think 36/40 is probably a very good number (hot).

mooty

i set my at 29/33 or there abouts.
on streets, i can only raise the pressure by about 2psi.

RS 197

anyone have 5k miles on there tires?? If so are they wearing on the inside. Mine were shot, the wear pattern was way less as it worked to the outside of the tire.

mooty

i have 4500 miles on mine.
alignment is per manual (track setting).
wear pattern is even across, with some chamfering suggesting the car pushes (which it does at the moment).

bear in mind 1/5 of those miles were on track, so it may have helped to even out wear. if i only drove on the street with that alignment, i would have more inside wear for sure.

rmag

Just replaced mine at 6k miles. Street and 10+ track days. Have track alignment. Wore a bit unevenly... rears were corded on the inside and outside had a bit of meat still left. But I attribute that to the track alignment and all the street driving I do also.

RS 197

If I am not tracking the car, does it make sense to add air pressure to even out the tire wear??

mooty

well, i wouldn't just increase/decrease air pressure to compensate wear. you need to find out the real issues.

does your alignment fit how you use the car.
my guess is it doesn't. if that's the case, change the alignment.
if it does, then perhaps your tire pressure was off. then i would correct the pressure, but i would not deviate from factory numbers too much.

YA911Fan

Should a buyer just assume that a new GT3 (or any P, for that matter) being delivered needs an alignment?

Bob Rouleau

Inside edge wear is a function of camber AND toe in.

NoSubEDU

I'll say that my alignment feels very well footed coming straight from the dealer. I haven't taken it on the track just yet, but the car seems to stick pretty darn well and at any speed. Of course power has the ability to change that but I find the stick is great.

I have no idea what the exact settings are but it's whatever came from the factory.

I have the Pirelli's, not sure if that means anything. And I'll report again after my first circuit.

mooty

yes, you should always chk alignment even on new cars.
and i dont always trust the dealer's alignment guy either.

doc2s

my front ride height was 11mm higher than stock. alignment was off too.