Originally Posted by grimmeRST
it will never hold 9 psi anyway, rst's can never hold air in, on mine peaks at 21-22psi but hold 17psi, and everything on my engine is basically new!
That all depends on your set up and where the boost pipe are connected etc. I see you have a GRS, have you got one of your boost pipes going to your cross over pipe?
Back in the day before I had my boost controller, my GRS used to loose 4psi from peak to hold, went for the cross over mod and it didn't drop anymore, and I still use this meathod now. Basically the air going through the throttle body holds the actuator open.
Best picture I had to hand.