Caster is pretty much fixed in the design of the Zeta suspension. It would require adjustment plates at the top of the struts to change caster--race level stuff. Note this listing (by CP) in another forum - caster plates and other suspension parts
There is an acceptable range to allow for production variation and to tell if there is something "wrong" with the car if caster is outside acceptable range. Camber and toe are adjustable.
There is an acceptable range to allow for production variation and to tell if there is something "wrong" with the car if caster is outside acceptable range. Camber and toe are adjustable.