jimivice wrote:... but what dictates the amount of power?
Is it just a matter of boost?
Power is a function of Mass flow. Move more air/fuel , make more power.
Boost gets a lot of attention, because it is easy to measure.
"Boost" is resistance to flow. Reducing this resistance by installing larger valves, porting, cam, etc allows for increased Mass flow at a lower boost level. Hence "making more power with less boost".
My reading here suggests:
"good normally aspirated motors, make forced induction motors."
I suspect the application is also important.