maybe a silly question but i had a turbosmart copy dump valve on my 98 impreza was really loud,too loud for me,i gave it to my brother who has a 94 wagon and you can hardly here it ,any ideas,its fitted in right place cause took of baileys one.

 

anybody

 

Will probably be to do with the amount of boost he is running, I'm geussing that your Brother's car is running less boost therefore not opening the dumpvalve as much as yours did meaning less noise.

 

Hes probably running less boost than you and the DV's vent from a different place on the Phase 1 engine no doubt that has an effect.