Hi lotusPaul,
good info above. To add a slightly different angle onto what you've said - your maths for the increase in air are based on CFM and you've used a linear scale to work out how much extra CFM you need to generate boost - I don't think this is quite right.
CFM is a measurement of volume, and as the air compresses within the intake system, it's density goes up and as such, I think your workings out should be looking at Mass Flow rates.
Not claiming to be any kind of expert, just regurgitating the info picked over time.