Hey guys, I have an 05 SC car, manual trans. Only makes 5 pounds of boost at wide open throttle. Was reading to disconnect a vacuum line on the bypass valve. Which is on top of the supercharger. I wasn't sure if people were saying to disconnect the vacuum line that goes to valve then supercharger. Or the bottom vacuum line that goes to the bypass valve and a solenoid. When I disconnected the bottom vacuum line, I didn't hear any hissing sound, nor did the car idle different. But when I disconnected the upper vacuum line, it idled bad.
Is the bypass valve the source of my problem, or do I need to look elsewhere?

 

Disconnect the line that goes to the bypass solenoid and plug it on the solenoid side so it doesn't become a vacuum leak. It will only be a vacuum leak in your solenoid doesn't have power or the ECU is commanding it open. If you pulled that line and it wasn't sucking air that is a good sign that your bypass solenoid is receiving power and is working correctly. Maybe your ECU is commanding it open when you get into boost because of some issue it is detecting. Don't disconnect the line going from they bypass valve to the supercharger neck behind the TB. This is what keeps your supercharger from trying to suck air behind a closed throttle body.

 

Thanks. I'll scan it and see if there are any stored codes.