If its on the left at the front its been relocated to the cold side. Makes a crisper pshhh sound.
Id run a recerc valve personally but they can run without anything at all... People put the dump valves on because there louder.
If its not throwing you back in your seat it could well be a split Vaccuum pipe.
If you get some silicone piping... 3mm id and look for the n249 bypass and stuff You can get it down 2, 3 bits of silicone pipe and itll boost better... Not alot mind.
Remap is the major thing to change it