How to use a BOV from a DSM
click to enlarge:
Rerouting the air releasing from the BOV helps to keep the boost up once you shift. And also help to help the air to fuel ratio correct.
And since the Starion/Conquests doesn't use a MAP sensor instead they use a MAF. I believe that releasing the blow off air into the atmosphere will not get detected by the MAF since it's in the air box and will send a false signal to the computor, not like the MAP sensor that's in the intake plenum and that would sense the change in the intake.