[Dave at Pelican Parts]

The only way springs affect your camber is by raising or lowering the car's ride height. Or, more specifically, changing the angle that the trailing arm makes to the body at its static ride height.

The ratio of shim to camber angle is not constant; expect it to change at least a bit throughout the range of adjustment.

A static camber measurement of -2.6 degrees with no shims is a bit outside the norm, at least at something close to stock ride height. If your car is slammed, that becomes more reasonable. But most likely a slammed car won't be shooting for the -0.5 degrees of negative camber that is the stock spec; that is for a street-only car with stock soft suspension at stock ride height. A lowered car with stiffer springs being driven in an aggressive-enough manner will definitely want more negative camber than the stock setting.

Your suspension is a system, and must be approached as a system. Changing just one part is going to change the behavior of the car. For instance, just changing the rear springs to 180 lb/in and leaving everything else stock is going to give you a harsh ride and a car that oversteers quite a bit. The oversteer can be reduced by going up in torsion bar sizes in front, or by adding a larger front sway bar, or both. Or you can go with a more-moderate spring rate in the rear, like 100 lb/in. (That is stiffer than any stock 914 spring, but still not that stiff.) It might be a good idea to add a front sway bar if you do that swap and your car doesn't already have one. The 140 lb/in springs definitely require front suspension changes to tune out excessive oversteer, in my experience.

Alignment settings depend on the suspension parts, driving style, and more. A decent starting point for an aggressive street driven car with stock or close to stock suspension is -1.5 degrees camber in the rear and -1.0 in the front. That is just a starting point, though, and you should pay attention to the behavior of the car at the limit, to tire wear, and if you are tracking the car to tire temps. Those will help you dial the adjustments in for your particular application.

--DD