I'm just curious about this cause I watch rally racing all the time on Speed Channel and it looks like all the Pro Rally cars all have to use the same type of BOV. They make this flutering sound when they shift and down shift. Either that or its the waste gate but waste gates sound like garbage. But does anyone know who makes them , what kind are they, and where you can get 'em. I have yet to see anyone here in the states use one cause the sound they make is one of a kind and I have yet to see any of these big name companies have one that sounds like it. and it would be slick to be different since everyone basicly uses SSQ and the Type-S.

 

most use dump valves, and they have diffrent setups than road cars. They have systems that keep the turbo spooled up when they slow down and brake. That is what you are hearing.

 

Oh.... I guess I can't use it then. Because you can only hear it when they shift and down shift I thought it was just a special type of BOV. The Dump valves that they're using then still sound sweet. Thanks for the info though.