After having some suspension work I'm getting my car aligned next week. The car has Bilstein PSS-9 and is lowered to lowest setting allowed on the PSS9 specifications. The car is used primarily for spirited street driving (I have another dedicated DE car).

Should I just go with the factory alignment specifications or is there a recommendation for improved handling without being overly destructive on the tires? Are there different factory alignment specifications for the GT2 vs Turbo?

Thanks for the recommendations.

Keith

 

what you need is a stage 2 track alignment i dont know the exact specs but the dealer or tuner will

they drop the front end a little and turn in the front wheels, turn in will be just what u are after.

i have pss9s works perfectly

 

I also have PSS9 with TRG droplinks and have a street/track setup and actually going in for a few tweaks in the next few weeks but it has worked very well for me. I did stiffen up the PSS9s a notches.

 

Here's what I'm running on my daily driver:

Front:
Camber: -1.5
Caster: 8.75
Toe: 1/16" in

Rear:
Camber: -2
Toe: 1/8" in

I couldn't be happier with my handling. FYI I have GT3 front control arms to get the extra camber and caster.

 

yes I have the drop links, strut braces and eibach sways as well,if I was you I would be changing the factory drop links to tarret or any of the other after market.

just pushing a little bit hard you can feel the factory drop links bend and its a terrible unnerving sensation when you really push it.

Drop links is small money very well spent.

 

You want a little lower front ride height Vs the rear to start off with, Now we are talking about 5 to 10mm on the wheel well lips to the ground.

Front camber you can get a bit crazy with and it really does not wear tires like the rears will wear. And with these specs you will be very happy for street.

Front Camber get as much as you can up to about -2.3. -1.5 is very very mild for the front camber.

Rear Camber -1.9

Front toe a good number is .25mm to .5mm toe in per side. So .5mm to 1mm overall toe in. If you want a little bit more aggressive steering go dead neutral.

Rear toe in; a great aggressive but easy on tires number is -1.75mm left and right. You want dead equal on this number in the back. Even minor variations has profound effect on handling.

This is a great all around street set up that is easy on tires and it also handles well.

 

But at what caster? Caster gives you more negative camber on the outside wheel when turning. I can tell you that my -1.5 static camber plus 8.75 deg caster gives nearly the same camber mid-corner as your -2.3 static camber with the factory 7.5 deg caster in most low speed turns. And my tires last longer and I can brake harder.

Just my 2c for a street setup. For a track car, this all goes out the window!

 

Man that is really off topic from what the OP asked don't you think??

Come on man...

The OP said he uses the car for street and has another car for track use.

For a street car... Lowering it with the PSS-9's and the improvement in shock valving over the OEM suspension will yield a huge improvement from where you are now.

My recommendation... Have them align it to OEM specs. No need for aggressive alignment specs on a street car if you're not going to put it on a track.

PSS-9's properly corner balanced and the ride height set within Bilstein's specified range with OEM alignment will be fantastic.

- Chris.

 

No, I don't think it was off topic. I was discussing the merits of one type of street setup vs. another.

I also strongly disagree with the statement that the stock settings are good for the street. They are ridiculously timid and were published to keep inexperienced drivers from ending up in the bushes. Simple toe changes can completely transform the vehicle into the proper sports car that the engineers originally envisioned.

 

I read your original post and your specs really aren't out of line. In fact the toe you're suggesting would likely yield nice high speed stability.

I guess what I am really trying to belay is the suspension component change alone over the oem pieces will yield a very noticeable change in handling/ride characteristics. - I feel like it's a good idea to start out with with the factory alignment specs at this point for a baseline and then evaluate the overall feel of the car.

What are your thoughts?

 

May I ask how you are adjusting your caster on a 996 Turbo?

 

Would someone help me understand the values for how toe is measured. I understand that toe out has the front of the tire pointing outward and toe-in pointing to the center line of car.

What I don't understand is I see a lot of discussing about having like 1/32 or 1/16 toe? and total toe. I'm not sure how that relates to the figures below from the Porsche Repair Maual where they show +5' +- 5'

Also it seems that to have crisper steering/turn-in people suggest going to almost neutral in the front with still a bit of toe-in for rear. Is that correct?

Thanks.


Porsche Repair Manual Wheel alignment Values

Turbo USA TurboRoW Turbo X73 GT2
Front axle
Toe unpressed (total) + 5' ± 5' + 5' ± 5' + 5' ± 5' + 8' ± 2'

Toe difference angle at 20° lock − 1° 20' ± 30' − 1° 50' ± 30' − 1° 50' ± 30' − 1° 50' ±30’

Camber (with wheels in straight−ahead 0° ± 15' − 30' ± 15' − 45' ± 15' − 1° ± 5'
position)

max. difference, left to right 20' 20' 20' 10'

Caster 8° ± 30' 8° ± 30' 8° ± 30' 8° ± 30'

max. difference, left to right 40' 40' 40' 40'

Rear axle
Toe per wheel + 10' ± 5' + 10' ± 5' + 10' ± 5' + 13' ± 2'

max. difference, left to right 10' 10' 10' 5'

Camber − 1° 25' ± 15' − 1° 25' ± 15' − 1° 40' ± 15' − 1° 50' ±

 

Most alignment shops using strings talk about toe in linear distances because it's exactly what they measure: the difference in length between two points at the front of the wheel and two at the rear. So a toed in car will have a shorter distance between the front points, giving +1/16" of a difference, for example. Other shops have nice computerized alignment racks that can measure angles directly. That's what Porsche is quoting.

Yes, zero toe up front is great for turn in on these cars. And you ALWAYS want toe in at the rear of any moderately powerful car, this helps keep the car stable.


And Engine Guy - as mentioned in my first post, I use GT3 control arms to increase caster.

 

Ahhh yeah sorry I missed that, I will stop thinking you were drunk when you typed that now!

I am 8.25 and -2.3 camber via a tarret upper mount and some love with a dremel to the upper mount holes when BBI did the alignment not to long ago. Since then I added the caster and reworked my front trailing arm shims for even more anti-dive.

The suspension on these things stock is actually quite gross. Add a stack of cash and a 996 can be turned into something unreal.

 

So when people talk about using 1/16" to 1/32" toe in, what would that translate in terms of degrees?

And when the above Porsche specification shows +5' =/- 5', is that a 5 minutes of a degree? If that's the case, then it seems the GT2 specification of +8' =/-2' is calling for more toe in than the standard Turbo?

Just trying to understand what I should ask for and see as results on a US alignment machine.

Thanks.