Has anyone out there swapped the blow off valve in thier 2000-04 S40 for an aftermarket one? Is it possible? Will it help power? I want more power and / or the cool sound of the loud wooosh of the aftermarket ones.

 

You can install a cone filter with the kit from Eurosportuning and get the noise you wish.

Adding the blow off valve helps sometimes and other times makes it run worse.

 

Why would the cone filter give me the louder blow off sound? Does the BOV vent into the intake? Or does it vent into the atmosphere? If it vents back into the intake, then the intake system would be the obvious choice, because, albiet small, the power increase would be an added bonus. Thanks for the help, your input is appreciated.

 

As far as I know it vents back into the intake.

 

Good to know, that will definitely be my next purchase. Thanks again.