i figured this is the closest place to post this, but a BOV blows off under boost, relives pressure when boosting and then theres no where for boost to go, but how would a BOV blow off when both my gauges read VAC?
im special, excusse my spelling and lack of intelgence
thanks
you are special 
OK, seriously though. a BOV typically “blows off” under vac, or when the system is pressurized, then it sees vac. Hence where the whoosh sound comes from. When your boosting the thing that relieves boost pressure from keeping on building is your wastegate, which is often a charge actuated “BOV” in a sense, instead of a vac actuated. Make sense now??
wat?! does a wastegate not allow exhaust gases to bypass the hot side of the turbo so boost pressure does not increase past wat is set ont he mbc or ebc in combination with the wastegate spring?
o yea im am a complete idot i total forgot it was hooked to the wasgate and it was there haha im sure i’ll get shit for this tonight lol thanks im just trying to learn
thye BOV gets hooked to the intake manifold, when the throttle body closes and the BOV sees vacuum, the BOV opens to release pressure in the intercooler piping
the spring in the BOV should be strong enough that it only opens when theres vacuum in the manifold AND pressure in the intercooler piping
since your gauge should also be hooked to the intake manifold, it will read manifold vacuum when ever the BOV opens
yes it all makes sence now!!!
lol thanks ya’ll