Originally Posted by SykSVT
Thanks Geezer for the info about the suspension. I'm trying to find who makes a spring with high spring rates for the SVTf. I keep coming back to GC (eibach) as the only player in town. I did read an article online of a "Custom Racing" magazine that actually cut one for their application (80's Audi), but I thought that was a big "No, No"? Other than that the Bilsteins wouldn't work unless I went with coilovers or used the GC's. Correct?
As a rule of thumb, springs for rally are not overally stiff. Rarely are they much more than 1.5 times stiffer than a stock spring. It's the shock that takes on most of the work. The keys to the spring are length and spacing between coils to prevent binding. There are springs with fewer coils, but have a little thicker wire, that work well for rally purposes. Eibach has a race series catalog with hundreds (thousands?) of applications based on diameter, length, number of coils, and rates. Some years ago I wrote to them and they sent me the catalog which seemd to be about the thickness of a decent magazine. There are a couple of other lessor known performance spring manufacturers and I'll try to track them down for you. And yes cutting springs is rarely advisable as it can effect the structural integrity of the spring as well as changes the spring rate.
Here's one of the US companies with decent spring selection and used by a number of rally car builders: http://www.bluecoilspring.com/