BOV/CBV: Use for intake side, when you accelerate to certain rpm, the turbo will start spin and compress air in to your engine, but once u release the padel, they are still a lot of compressed air inside your piping, if without BOV/CBV to blow it out, the air will direct impact back to the turbo fin!!!! Imagines, the air impact the fin opposition; does u think the fin can last longer? So actually BOV/CBV is use for protect the turbo. But now can use for scared Amoi beside the road also!!! keke

Wastegate: Use for exhaust side, when u accelerate to certain rpm, the exhaust gas will start blow the fin and get the other side of the compress fin spin, both 2 fin are spin on opposition; but u can't let the exhaust gas unlimited to blow at the fin right, so the Actuator will help to wind out the extra gas back to the exhaust.it have a larger vent and more stable than the actuator, it can be wind out the extra gas to the air or back to the exhaust. If u winds out to the air, u can scare the whole road of Amoi!!!! wakakakakakak!!!!

2 of them are different thing..
hope my info help...

This post has been edited by national12345: Jun 26 2007, 10:12 PM