[Walt Fricke]

The 935 spring plate system does not affect suspension geometry directly. It is only used with coilovers. Coilovers are a plus with a full on race car, because you can get much stiffer rates with them than with torsion bars. And they are easy to change, and make corner balancing and ride height setting a snap.

Plus the heims used at the torsion tube attachment are nicely low on friction. On top of that, you can devise a higher outer pivot point.

935 setups normally also include adjustable (or fixed raised) inner banana arm mounts. This allows quite a bit of flexibility in futzing with roll centers, and the camber change with roll effects too (?). This is normally done in conjunction with raising the outer pivot, to lower the car but keep rates (other than the CG effect) where you want them.

If the ASP is the system where the spring plate is essentially two articulated longitudinal members, I think the jury is still out on how much it helps. I think it is also a coilover only system, but can't remember.

What I do know is that it is not legal for PCA Club Racing. If you are just DE'ing, or race with a venue which doesn't care about such things, then it certainly is an intriguing idea.

You can adjust rear negative gain in the way the 930 Turbo did (and the RSR of that era earlier): shorten the banana arm and move the pivot rearward (and more or less inward, depending). Not a bolt-on deal, to be sure. The RSR banana I think was steel and was cut and welded? The 930 banana was cast shorter. Desireable piece, with $ appropriate to that. You can get kits to weld on fixed relocated inner mounts for that piece.