Exactly as posted. I've put an Orranje Stealth CAI - Cold Air Intake on mine. Which I believe is the same as the DaveF referenced by Minione above. Pulley is still standard on mine. Changing (reducing) the pulley that drives the the supercharger (SC) makes the SC go faster at the same engine revs which therefore a) pumps more charge (the air and fuel that makes the bang that drives the piston) into the engine b) makes more whine.
Here is a link to KAV Motorsport who are one of the main suppliers of modified pulleys: Mini Cooper S supercharger pulley
Back to whine. If you have a standard panel filter you won't hear the whine - much. With a CAI you will, much louder and nice if you like that kind of thing, which I for one, do.
Why is this I hear you ask. A CAI lets the intake side breath better. Most of them, inc. the Orranje CAI, require you to cut a larger hole in the plastic 'bulkhead' panel at the back of the engine so it sucks air in from there. Now it so happens that that is where the car gets air for the cabin ventilation system - the black plastic grills in front of the windscreen, in this case the one on the passenger side. So now the CAI is sucking air from there AND the cabin air is coming in through the same space. Therefore the whine of the SC slurping air through there can be heard much more loudly inside the cabin. And there you have it.
If you put said pulley on you will get even more whine.
Link to the Orranje Stealth CAI: https://orranje.co.uk/product/orranj...air-intake-kit
You can go up to a 15% pulley without needing to go to a larger intercooler (IC). If you go 17% you need to sort the IC. That is because the more the SC compresses the air the hotter it gets (hotter air = bad). Therefore a larger IC will lower the temp of the air being pumped by the SC into the engine. And you would then need to remap the ECU to deal with it all.
The Orranje is very reasonable at £125. There are numbers of other CAIs which are much more money. One of the things I like about the Orranje, apart from the excellent whine, is that when you look in the engine bay you can't see it is fitted. Looks as though you still have the standard panel filter set up. Hence the 'Stealth' moniker.
Pic of it fitted and the panel to it's right that has the bigger hole cut in it - that you can't see.
Hope this helps.