exactly how it is plumbed and what equipment you have. I don't know for sure what stock wastegate spring tension is but many upgraded turbos come with springs set for 12 PSI. So if you are still plumbed into the intake at all it should stop boosting at the point where the intake pressure overcomes the springs. Electronic boost controllers prevent the pressure from reaching the wastgate diaphram until the boost approaches the setpoint then they modulate the flow to control the point where the pressure is allowed to start opening the wastegate. Manual boost controllers allow the pressure to build but they slow it down to allow more time for boost to build.
This is why EBC's are preferred. They allow boost to build quickly to near peak before allowing any drop opening of the gate. Manual controllers just slow the gate action. It starts to open sooner than an EBC would allow so peak boost takes longer to happen and lasts a shorter time.
