Recently put K&N57i induction kit into my VXR plus DV-26d valve. Really chatters but not much of a dump noise. Is this right? I thought you just heard the turbo spinning, a little chatter and then a loud dump which is normal on most cars, but it seems to be the other way round - a really loud chatter and then a little 'pffftt' (slight dump noise) after. Anyone got any ideas?