Please don't misinform him and say that BOVs are useless. Consider that BOVs come standard on our cars in the form of CBVs so yes, there is no NEED for them unless your CBV is torn or is going to obviously tear based on future modding. A BOV vents the air that has not entered the block when throttle is closed...if it were not vented it would hit the closed throttle plate & reverse back towards the compressor housing, reversion & attempt to spin the blades in the reverse direction aka compressor surge. "The sole purpose of this device? TO PREVENT COMPRESSOR SURGE. Once the throttle plate snaps shut, the entire intake is pressurized. If that pressure spikes too high, it creates backpressure on the compressor turbine and can, in fact, damage the turbo. You could end up with anything from bent blades on the compressor wheel to a snapped shaft. (Imagine two wheels connected together by a shaft. Both are spinning at the same speed. Suddenly, you grab one and bring it to a dead stop while the other one is still spinning at the same speed it was spinning at. What do you supposed will happen? Something's gotta give.) A BOV is insurance against that. When the manifold goes into vacuum (When the throttle plate slams shut, the engine is still trying to ingest air. Because it's not being provided, it's sucking from the manifold and creating a vacuum situation.), the BOV is opened and excess pressure in the intake tract is vented into the atmosphere. It, in no way, regulates boost. So whether it's 7 psi, 2 psi, 12 psi, or 30 psi, it won't matter. You need a BOV." - a honda guy, :ph34r: