A comparison of Intrax and Eibach rear springs on the 1995 Saab 900
Intrax springs have a barrel design, where it has a number of softer coils
which are always fully compressed to compensate for a shorter length and
provide some preload when the car is up in the air. The downside is that
there's only a couple of coils left uncompressed, which limits the suspension
travel, and the ride suffers a lot. Eibach, on the other hand, uses a
progressive design, where the thickess and stiffness of the coils varies
through the spring length. It employs all of the coils at various stages of
the suspension travel, which allows for a much more comfortable ride without
having to make the spring too soft to sacrifice the handling.
You can see how the spring is almost fully tight under the weight of the
car, except for the last coil. There's virtually no room for the spring to
compress further, which means the car will bottom out on every bump.
Here's a new trick for removing the bump stop, suggested by Jose De Jesus.
Compress the rubber piece with a hose clamp, spray it with some soap
water, and it pops right out.
Off the car
The differences in the spring design are apparent from this picture. The
quality differs a lot too - both springs were on the car for about a year.
The Intrax is all rusted and peeling, while the Eibach still looks like new.
A new spring installed (the installation procedure is described in
From the looks of it, it appears that the ride
is going to be much more comfortable.
Installation complete. The ride height looks just perfect.
Intrax vs Eibach
Here's a direct comparison of both springs installed in the same corner.