'95 993

Anyone experienced any bad tire wear on the track?

My friend's 997 S, with chrono package has been through two left hand front tires in three track days (D.E. events) here in the UK (clockwise circuit)!

The problem is the very outside inch of the tread (shoulder) seems to be taking all the wear and it gets down to the layer below and starts to delaminate after 1.5 track days!!

The car has very few miles (less than 1000), dealership to home, home to the track and back only.

Any other experiences and anyone got access to suspension settings? I reckon that the camber is out. It goes back to dealer on Friday but I reckon this will be one of the first they have had to set the suspension up on and almost certainly not for the track.

Any experiences, technical specs, advice etc?

Many thanks

John

P.S. What an awesome car keeps up with the GT3's and gives them a serious fright (I know it depends on the driver but still a very, very quick car on the track)

930man

i was at the track this weekend three day event the tires were fine, 9 previous days on the ps2s and they will problaly make one more event. the car is great on the track. There was a 997 s there and his left front tile competly delaminated after the second day I think the tires got to hot they were running back to back drivers. i was very very surprised of the PS2's the whole outside edge of the tire was shot.

rss997

Too low air pressure and positive camber will do it...With the crappy alignment from the factory it is no wonder the front edges are getting smoked...

I am getting mine aligned and lowered on Wed!!! Bye, bye pushing like a snow plow!

PDQ PDK CAYMAN S

Porsche will pay for an alignment within the first 2,000 miles. I have 10 hours of track time and the tire wear if perfect. My insts. for the work was to make the tires last as long as possible.

Bob Rouleau

John - wearing the shoulder of the left front on a clockwise circuit is indicative of two things:

1) The driver is using his car correctly
2) There is insufficient negative camber.

Note, used on a race circuit with factory camber settings, all the tires will wear out prematurely at the outside edge or "shoulder". The effect will be more pronounced on the left side when driving clockwise tracks and on the right if the reverse.

To avoid premature wear of the tires (his left rear is probably in sad shape as well) you need to increase camber to around negative 2.5 degrees. This provides nice ever wear across the tread surface when used on the race track. On the other hand if he does a lot of street miles, he will prematurely wear out the inside edge of the tires. The additional camber also provides better cornering grip because when loaded the tire is square to the track surface (hence even wear).

Compromises are possible, negative 2 in front and neg 2.2 in the rear will work decently on the track and still provide decent tire life on the road.


Have him check inflation pressures - his street tires should measure 40 lbs HOT i.e. take the pressure as soon as the car enters the pits. If over that, bleed the pressure down to 40 lbs while still hot.

regards,

930man

Hey Bob,

"his street tires should measure 40 lbs HOT i.e. take the pressure as soon as the car enters the pits. If over that, bleed the pressure down to 40 lbs while still hot. "

are you running 40 lbs in the front hot? i was Running 38 lbs front 42 lbs rear hot i did still get some pushing in the front maybe i should go up a a couple of pounds front.

will the dealer change the camber without a problem? i did get some shoulder wear but the ps2's worked very well for street tires over 50% left 5000 miles and 9 days on the track

'95 993

Guys,

thanks for replies and advice, the car goes back to the dealer this afternoon (tuesday), so we can "suggest" the correct negative camber settings to their mechanic

John

Ronnie

less than a 1000 miles and already hard tracking it?

btw, what track are you using here in UK?

Bob Rouleau

930man - Yes, I do suggest 40 hot all around on street tires. After that you can fine tune and perhaps prefer a stagger i.e., lower pressure in front, 38F 40R is not unusual. As you know, a 911 understeers in slow corners (but not in fast ones if correctly set up) which is why God invented trail-braking;D

'95 993

But of course.

It's life so far has been:

Exeter to Cheltenham, Cheltenham to castle Combe (twice) and cheltenham to Goodwood once!

It was run in at Castle Combe!

Has been to PCGB track days so far

John

Ronnie

dude where abouts in Chelt are you.

What a small world!!

930man

thanks bob i have been using the trail braking how sweet it is in the 997!

'95 993

Hi Ronnie,

You in Cheltenham as well?

I am in Leckhampton

Do you do any track days?

John