Does the Bailey dump valve look like the standard one?
The reason I ask is, my car makes a fair whoosh sound as if it has a dump valve. I'm almost certain it doesn't unless the Bailey one looks like the standard one. I know the car has previously had a Bailey Dump valve fitted as it's in the list of receipts I have for the car.
I'm thinking the mods like the APS induction kit have enhanced the sound of the standard dump valve.