Why would i have no boost control?

Just put a 96 wrx motor in the Legacy and it runs real smooth, BUT i have no boost control it hits 20+psi in a split second and then cuts out. I dont like it when it does that. Its already blown the ic off at the throttle. I didnt touch anything to do with the boost solenoid or boost controller. Its a turbosmart dual stage controller.

Cheers guys and gals

ANDY