Mines the same buddy, I've got nothing extra fitted to it and i play with this all time u can hear it best if u let go of acc pedal mid boost about 4k

Get a distincished pssssh noise as if u would if had a dump!
 
Yeh that's it, soon as boost comes on let go of the acc and you can here it at it's loudest
 
Yeah excellent isn't I'm still considering getting a spacer to make it a but louder lol

How sad and chavy!!