Originally Posted by sparoz
I am not sure about losing 5-7hp as I have seen no data on this. I would say theoretically at higher rpm where our stock turbo struggles would see some benefit having air recycled back after the turbo.
Now, BOV has been run on many N54 without any report of loss of power so it might not be significant.
That swoosh sound many people like to hear carries some energy - but probably not that significant.
A valve that allows excessive air build-up to escape once the throttle bottle closes does nothing to add, nor take away, horsepower created by the engine. Could allowing the air to vent outside create a small lag in the throttle response in the time it takes to fill the intake back with air immediately afterwards? yea... but by no means does an external venting BOV do anything to the HP, especially not take away 5-7 as stated above. Or... because bullshit. like I said. Lol