The problem is we did double the spring pressure and the max boost didn't increase.

The older greddy has the old style soliniod that a square box thats about a 4x4 inch box.

Wish 20psi spring it should hold. I'm not going to put any more spring pressure in it. If it's the controller I might try to bleed the boost to the controller. When I tried to bleed it to the spring it would hold to a certain point and then be overcome which made for a nice boost spike.