DUMP VALVES ??

[Bardolphs]

As we all know, the Noble has a very distinctive sound.
Can anyone explain what and where the noises originate.

I was under the impression that dump valves were a standard fit, which would explain the alternating whoosh when coming off the gas. As my car (2.5 GTO)does not appear to have them fitted, can anyone explain the workings ?

Cheers..