Nice pictures. This is a pressure activated wastegate controller. It will allow boost till 14 PSI then it opens. If you lengthen the rod length it will open earlier than 14 PSI.
It should normally be closed. It will open when the pressure acts on the actuator. You'd want to apply pressure not vac to the actuator.
See this link to see how to hook it up for the short line to actuate:
http://www.peachparts.com/shopforum/showpost.php?p=1761755&postcount=8
Heres the links to images from gsrx:
http://www.peachparts.com/shopforum/showpost.php?p=2134931&postcount=137