rear coil-overs

[Simon]

Originally Posted by petevw

From what i know they are 944T AL arms with Bilstein/Eibach coilovers and Remmele Uniball springplates. I don't know the details of the springrates.

AFAIK they are GWD/Gerd Weiser rear coil-overs.
I was about to call him anyway, so I will ask him about the spacing of the springs in combination with the 944 arms.
They are 60mm ID springs (see below), which AFAIK should fit.
At least they do on 944's.

Originally Posted by petevw

What is the purpose of the dual spring setup? Pulling the bottom one out should get me to where i want.

I will ask Gerd Weiser about this too. I'd suggest to keep it.
The helper springs are there to keep some force on the main springs when the damper is fully extended. They also have some influence on the suspensions force-curve (only on the low forces, since they are rated lower than the main springs).

Originally Posted by petevw

Alex, do you know what it the thread on the inside on the arm? If its M14 x 1.25 or M14 x 1.75, that would explain the M14 x 1.5 bolt stripping it out.

They are M14 x 1,5 x 85mm.

Originally Posted by petevw

The springs are marked,

Top black,
Eibach 41/99
ERS 140-60-120

Bottom Red
Eibach 27/98
ERS 40-60-55

How do we know the springrates?

They are Eibach ERS springs.

For the main springs (the black ones):
- the 1st number is the free/extended length
- the 2nd number is the ID (Inside Diameter)
- the 3rd number is the springrate

Since these springs are "European" type springs (i.e. with a 60mm ID), the values in their names are in European/SI units.
So the free length as well as the Inside Diameter are in mm and the spring rate is in N/mm.

This means the main spring you have is a 140mm long, 60mm ID, 120 N/mm (685 lbs/inch) spring.
It's spring travel is 71mm and it's compressed/coil-bind length is 69mm.

The tender springs (as they are called) numbering works almost the same, except that the first number represents the spring travel instead of the free/extend length of the spring.
So:
- the 1st number is the spring travel
- the 2nd number is the ID (Inside Diameter)
- the 3rd number is the springrate
So the tender spring is a 40mm free travel, 60mm ID, 55 N/mm (314 lbs/inch) spring.
It's a linear spring which free/extended length is 68mm and it's compressed/coil-bind length is 24mm.



For more specs/the search engine, see:
http://eibach.com and go Eibach ERS springs in the top menu.
or their motorsport catalog:
http://eibach.com/eibach/img/ers-catalog-2004.pdf

Originally Posted by Bug@5speed(US)

Here is a better pic of that rear lower adapter for 1/2 coilovers..

I will check my manual as I don't remember the size..
A

Alex, I can't see any pictures?
If you have some, could you post them?
I am interested in those bolts as well (they should be 2 part bolts AFAIK).