Hi,
question on behalf of a friend, can you get a dump valves with noise reducers?, he's wants a dump valve which doesnt sound like a knackered Rs turbo but still with some of the 'whoosh' noise, his car is a 1996 sti if this helps

 

he should get a re-circulating dump valve instead of a vent to atmosphere, still get whoosh but its a lot quieter and its better for the car.

 

Cheers for the help, ill pass that on to him

 

induction kit will acentuate(sp) the sound to