Mikelly

Guys, I'm running OEM tires on the street and Michelin Pilot sport cups on the track with PSS9s. I want to drive this car on the street and at the track... What are REASONABLE alignment specs I can take to my shop for an alignment???

Mike

Acropora

I've been running -2 camber, going to -2.5 soon.

Kerry

Unless you have camber plates, you won't be able to get more than ~ -1 camber in the front; even that much requires a lowered car. So go with max negative camber up front. In the rear you can get as much negative camber as you want. Steely-eyed track men run with even camber all around. I run a 1 deg differential between front & back. With my current setup that means -1 up front and -2 rear. -2 or -2.5 is generally accepted as the limit for reasonable street use/tire wear. I ran -1.5 in the rear for years and had little inside wear, within the lifespan of these tires, which isn't long. But, I was running auto-x on my street tires and that tends to keep the wear even and the lifespan of the tires very short. Now at -2 in the rear I'm seeing more inside wear. Combine that with the fact that I auto-x half the time on race rubber, and I'll probably be swapping the rears. Since the tires are directional that means mounting them inside out. With the fronts at -1 I still see no appreciable inside wear.

GreggT

There are different approaches........with street/bling 19" rubber at $1600 a set I stay 1.5 to 1.7 in rear and as Kerry said, about 1 less in front.
If you have track wheels and good R compound (like Mich SC you mentioned) for the track....I think it's the best of both worlds. More negative will definately cost you (more often) down the street. You would have to be the judge of whether it's worth it on the track......for me, know.
Also, besides the cost of street 19s, I'm not nuts about increasing the frequency of times those rims are in the shop......stuff happens, and it's a pain dealing with wheel repair-refinish.

Y65MPH

On my 996TT I run -2 rear and -2.5 front (with camber plates). Car has H&R suspension running 19" wheels.

Mikelly

The car has PSS9s and is lowered substantially, and is running 18 inch wheels... I'm not concerned as much with tire wear as I'm not driving more than 8K miles per year on the street.

Mike

TT Surgeon

With the X73 I had -1.5 fr and -2.0 rear, without camber plates. Ran like a scalded assed ape at the glen with cups, 2:15-2:20's all day long with a NA 996 C4S/aerokit.

Dr. T

Here's the settings I have for the X-73. I've been extremely happy with this.

Left front: Camber -1.0 Right Front: Camber -1.3
Caster 7.7 Caster 7.6
Toe 0.02 Toe 0.02


Front: Cross Camber 0.3
Cross Caster 0.1
Total Toe 0.04
Set Back 0.31


Left Rear: Camber -1.6 Right Rear: Camber -1.6
Toe 0.07 Toe 0.09

Total Toe 0.16
Thrust angle -0.01

Jean

Mikelly, in my opinion anything less than -2 deg camber all around is useless for the track. The likes of Manthey Racing use -2.3 Fr and -2.1 Rear for the street /occasional 'Ring setups, while -2.5 Fr and -2.3 Rear is for a bit more hardcore street/drivers.

Less camber in the front than rear and much lower tire pressures front vs rear, is the lawsuit-free, Porsche way of keeping some understeer as an added safety for their customers. When you want to do some performance driving, all of that is a major handicap to decent fast handling.....IMO