A brief introduction
My car was used when I bought it.
By chance (chance... by changing wheels for the third time ) I found out that I had Bilstein PSS9 installed but unfortunately I did not have:

• any skills to adjust them
• C spanners

So I went to a repair shop where I asked not to adjust them but to teach me how to do it and to sell me the spanners.
It was easier than expected and I wanted to share with you this easy and helpful (I hope) procedure.


What is needed

http://img440.imageshack.us/img440/3629/67786402.jpg

• Torque wrench
• Torque wrench extender
• Bilstein C spanners
• Caliper
• Pencil and paper (or similar)
• Floor jack (not in the pic)

Remove the wheel

Since my floor jack is not thin and and the car is (was) too low, some time ago I asked to my carpenter to build this small ramp in wood.

Here it is the spring absorber group.

You can see (at the bottom end of the blue spring) two black rings. The upper one is linked to the spring helper and the other one is to lock the upper one.
The two "pins" screwed to the wheel hub help to avoid that the wheel (while being taken out) will hang on the brake caliper. One should be in the car toolbox, the other one can be bought as a spare part from your stealer (cheap, around 10 usd, if I remember right)

Before starting "playing" with the height, I suggest you to write down a measure to be used as reference (refer to last picture below). In this way it will be easier to decide how much you want to change ride height.

Once you have taken the "as-is" measure, with the two C spanners (included in Bilstein kit, you can easily find them on ebay) you have to unscrew the two rings


Once unscrewed them you can set up ride height simply by turning the helper spring with your hand. The upper black ring will follow the spring.



Check the desired height.

Given the original measure, once you decided how much you want to lower or raise it, you can double check it with the caliper, and tighten in place the two rings.
As any Haynes manual teaches: "Refitting is the reverse sequence to removal"

I enjoyed doing it!
Before it was (all measures from floor to the wheel arch):
F: 65cm (25.6in) R: 68cm (26.8in)
Now:
F 66.5cm (26.2in) R 68cm (26.8in)

For reference:
997S (with no sport chassis)
F: 68cm (26.8in) R: 70cm

997 GT3 MKI
F: 66.5cm (26.2in) R: 67.5cm (26.6in)

Feel free to change/adjust the post.
I am not a native English speaker so for sure more than once I messed up words, sentences and similar

 

please be aware that any adjustment of ride height on any corner will change the corner balance of the vehicle and might effect the alignment...a change in ride height should be accompanied by a corner balance and alignment

 

Good point!
Since I put the old tires on the new rims I asked to the "tire man" for the alignment but he suggested me to wait a few hundreds kilometers in order to have everything settled properly.

 

Got it done (I had rear tires changed as well)
Before (prima) and after (dopo).
The guy was not able to fully adjust the camber of the front right wheel.
Do not know why...

 

to raise the car,, which way to turn the helper spring? move it up or down?

 

Move it up.
If you look at the pic you quoted, the thread that shines is where the helper spring was when the car was too low (for my garage ramp more than for me )