Forge do two different spacers if it's noise your after ? One fixed, Full blow off and the other, an adjustable one which has 3 settings, fully blow off which is loud, partial blow off/ partial re-circulate, slightly quieter and then full recirculate which is quiet and will help the car keep stronger boost. These are bolted onto the diverter valve. I personally don't have a dump valve just a revision D diverter valve which I will prob swap for a G soon. A nice induction kit and a standard diverter D or G revision combo will sound and perform better than adding a spacer just for noise. Each to their own I suppose