well you won't get it.
the turbo churns' up all the exhaust tones, so you just get a scouring noise when on boost, and when idling it will sound like a really big bumble bee in the bottom of a well!!!!
same applies to all turbo cars though (I think), is that after the turbo housing you can have pretty much anything you like!!
e.g my turbo volvo (sold and gone far away), i fitted a completly UNRESTRICTED that means no silencers no back box, just 3" stainless from turbo housing to the back of the car
wasn't that noisy when driving either, well it was. BUt not as noisy as I was expecting. only at idle did it sound ridiculous, and everything in the cabin would vibrate at one tone or another
when driving and on boost it would just make HUGE scouring noises, and sound like some kind of a ferry crossed with a 12" hairdrier, and a volvo estate
basically you are wanting to relieve build up pressure from down flow of the housing, which will make it spool faster, at lower rpms (usually), and relieve EGT tempretures (something which tuned turbodiesels have problems with, extreme EGT tempretures).
wheras NA cars you need backpressure to make it run right.
