Silencer:
Take your MAS off. The silencer is the little Y-shaped plastic thing inside of the intake hose. Takes a little work, but rock it back & forth until you can pull it out. It's inside the big black thing in this pic:
It made my BOV slightly louder, but as far as function, no difference.
As far as flipping it over, some people have had good luck with it others haven't. If it doesn't blow off properly you will hear a sound like the air is being cut up. That'd be compressor surge, not good. If you hear anything like that change it back.
Marius, how can you adjust the stock BOV? I'm looking at mine right now, & don't see anyway to do it.