Your 10 hp figure is a joke right? The Hp to turn a blower is based on the same principle you state later in your post. The hp required to turn a supercharger is based on how much boost its making. According to Procharger a F3R on a motor I built at 24 psi is taking 100 hp ( and a top fuel motor takes 1000hp at 40 pounds of boost) to turn. That is the reason for a 3 inch cog tooth belt. If it took 10 hp you would be able to use a v belt and a small one at that.
A turbo does create back pressure, thats true. However a turbo motor works on pressure differential. Lets say a N/A motor has 2 psi pressure in the exhaust while , lets say for the sake of another arguement, the intake has 0 psi. So a turbo motor on 22 pounds of boost has 5 pounds of back pressure in the header you still have a 17 pound pressure difference. Hence the general consensus that turbos are "free" HP. I honestly can say that turbo power is free because engines create heat and in creating this heat is how hp is made and a turbo takes advantage of the expanding gases to create even more wheel speed in the turbo. Not to mention when the turbo is up to speed since it is allowed to accelerate past the speed at which the exhaust is flowing it can actually have a scavenging effect.
No matter what your into an intercooler will make more hp than a non intercooled motor no matter how much boost. Obviously the more boost the more heat and the intercooler is more advantageous.
Centrifugal superchargers are friggin awesome as well as a turbo motor. Both make big power, both are not easy power, there is always a certain amount of pain and suffering to make big power. Just ask someone you know who has made big power.
Check it out, I recommend the book "maximum boost" by Corky Bell for some light reading to support what i just wrote.
