Throttle body spacer or blow off valve?

Question

I am confused here I don't know which one does what? Ok I'm not sure if it is the throttle body spacer that makes the shhhh sound when you shift or the blow off valve someone told me it was the throttle body spacer but I am thinking it is the blow off valve? Which one is it or is it both? I don't know please someone help!!!!

Also answer this question for me is the blow off valve just for cosmetics or does it actually do something? Please answer both. Thanks

Answer 1

the 'shhhh sound' is from the blow off valve. the purpose of the blow off valve is to dump the air thats being pumped in by the turbo rather than forcing it against a closed throttle. despite some valves being obnoxious, they are serving a real purpose