I've recently had an Alta 15% reduced supercharger pulley and Alta airbox fitted to my MCS - wow what a difference, so much more mid-range torque and such a great supercharger/induction noise! Because I can hear more of the supercharger at work, it has got me curious as to how to works though.
The impression I have is the intensity of the supercharger 'whine' is dependant on how much you have your foot to the floor, with the pitch varying according to engine revs, all obvious so far. What I'm curious about though is the almost complete lack of supercharger whine on light throttle, say cruising at 70 on the motorway. It sounds like the supercharger isn't spinning, but is that right (ie it's on some kind of clutch system) or is it just that I can't hear it because the throttle body is mostly closed?
I'm hearing a lot of new noises with the new airbox in, so I'm just curious on what's going on!