Wheel alignment specs for track/street?

[Mike the mechanic]

Hey guys, I'm hoping some of you track guys can chime in on this one.
This is for a 1985 Carrera, my buddy is a pretty serious track guy, he takes the 911 to the track at least 2-3 times a week. His car is lowered to just under Euro ride height, and he has 225/45 and 245/45/16 on 7.5 and 8.5" BBS. He is a very aggressive driver, and prefers his camber settings leaning towards track than street, and tire wear is not a problem, he doesn't mind dishing out for a new set of tires sooner, as long as he can get the most out of his car. Forgot to mention he has Koni Sports all around.

He's tired of going to wheel alignment shops, all they seem to do is make things worse!

My question is, does anyone know what are the optimum camber and toe settings for the front and rear of the car for track use? This way I can write it all down and present the specs to an alignment shop and tell them, " make it like this!"

Thanks to all in advance!

[stlrj]

all they seem to do is make things worse

What were his settings before they got worse? That might be the first place to start.

Joe

[masraum]

Well, the most common settings for street/track are

Frt
-1 cam, full (matching) caster and about 1/32-1/16 toe in
Rr
-1.5 cam and about 1/32" toe in

For a much more track oriented then he can add a half to a whole degree of camber all around depending upon what he can get and less toe in in the front, to actually a little toe out.
So maybe something like this

Frt
-2 deg cam, again full caster, and 1/32" toe out (the toe out will make the car very darty in a straight line, but it will turn in better)
Rr
-2.5 cam and 1/32 toe in

For anyone familiar with Todd Serota, Tracquest, or the Rennlist, Todd recommends equal camber front and rear. He has a bunch of track time, and used to race an '85 Carrera.

I think the equal camber may reduce understeer or possibly increase oversteer. I think it would depend upon your driving style.

[addictionMS]

I use

Frt
-2.6 deg cam, maxed out caster, and 1/16" toe out

Rr
-2.5 deg camber (max I can get) 1/16" toe in

so pretty close to what Steve suggested, so consider this a confirmation it is good advice

Jim

[pu911]

Can you get that much negative camber out of a stock 911 front end?
Phil

[steveW]

.......but remember there is absolutely no point in doing alignment if the suspension bushes haven't been upgraded or aren't in A1 condition...

[ChrisBennet]

There is a limit to the amount of camber you can get on a stock Carrera without resorting to "tricks" - tricks that an alignment shop wouldn't know unless they set up Porsches for the track. -1.0deg of camber in the front is the most I can get on my '86 for example.
In the front, you can do some stuff at the top of the shock tower to increase adjustment and a strut brace can be used to physically pull the shock towers together.
In the rear, as you increase rear camber, toe out increases. At some point you run out of toe adjustment so you can't go any further without modifying the spring plate.

There is other stuff but you get the idea. A "normal" alignment shop probably isn't going be able to increase the camber to where he wants it.

-Chris

[Vintage911Racer]

I run on my 67 911S Race car:

Front: -1.75 Camber
1/16 toe out

Rear: -2.25 Camber
1/16 Toe in

[masraum]

Gents, wouldn't lowering the car provide the opportunity for more Camber?