Originally Posted by EQ Tuning

This is one of the correct ways to set it up. Port 1 is normally open to Port 2 which pushes on the top of the wastegate and cancels out the signal to the bottom of the wastegate from the compressor cover. This allows the wastegate spring to keep the wastegate closed normally. When the ECU actuates the solenoid, it opens port 1 to port 3. This takes the signal away from the top of the wastegate and bleeds it off into the intake. This will allow the signal at the bottom port of the wastegate to open it. In this method, you're basically just controlling the pressure to the top of the wastegate to regulate it. This will give you good control with smooth spoolup but not necessarily the best response.

Another option is to eliminate the T, run the pressure source directly to port 1, run port 2 to the bottom of the wastegate, and run port 3 back to the intake. In this configuration you would leave the top port of the wastegate open to atmosphere. This will give you the ability to achieve better overall response but it may be a bit tougher to tune.

The first arrangement may be better to use with the prodrive solenoid as it has relatively small ports and can have a hard time flowing air quickly enough to fill the relatively large body of the EWG to actuate it. The second configuration is generally used with a larger solenoid body or with an MBC.

Thanks
-- Ed