put it on by about 10mm and make sure its locked using the nut (mine fell off recenlty cause it wasnt locked well enough). Stick it on the car and see what boost it holds, then shorten it by 2 turns and see how much it holds. hopefully it'll add boost at the same rate per turn, but it'll take at least two attempts to find out how much it increases per turn.

What is the actuator as a -31 should hold 5psi when wound out fully, and a -34 should be 11psi.

JAmes.