Which companies make blow off valves that can adjust the loudness of the sound (from quiet to loud) it makes?

I think A'PEXi makes one, the Twin Chamber B.O.V., am I correct? Who else makes something like that?

 

GFB makes one and is available through WORKS and GB Motorsports/ MPJ Performance.

 

Actually - I got the opportunity to see the GFB one (WORKS) at the SoCalEvo met this weekend. The price is a bit high for a b/o valve IMHO, but the quality is definitely there. The piece is made beautifully - very solid, with on the fly adjustable VTA simply by rotating the top of the BOV body. On top of that, the nipple for the vacuum (I think that's what it is anyways) is sandwiched between the ratcheting top and the body itself which had me a little concerned since I didn't want to keep adjusting the piping. Fortunately, they had that covered too - it spins independent of the rest of the housing so you can adjust without having to worry about the piping.

I don't normally pimp vendor products, but this was a very well built piece. If you've got the money and want to adjust your blow off volume, this is definitely a great way to go.

-Josh