how come I'm not seeing parasitic losses mentioned?
A blower takes a lot of power to spin, so it will take a higher boost pressure to make the same net power with a blower than a turbo setup, regardless of the blower type.
Granted, with a turbo, you lose most if not all of your exhaust scavenging effects, but that is small compared to the power required to spin a blower.
Like has been said before in a number of different ways, the characteristics of an engine, forced induction or not, need to be matched with the application for best results.
Case in point, I help build and race mustangs in Grand Am cup, I have the option of using a 5.0L DOHC in NA form, or a 4.6L DOHC w/ the stock cobra blower. Because our races are endurance races, where we stop for fuel, I would never consider the blown engine because of its fuel consumption, even though I can easily make more power with it.
