[Mule]

So if an engine makes say 320, like an S4, it does this on atmospheric pressure of 14.7 pounds per sq. in. Power is limited by how much air can flow through the engine. 1 bar or 14.7 pounds per sq. in. of boost basically doubles the amount of air and the amount of gas that can be burned and the amount of cylinder pressure that can be generated.

There are some losses in friction and efficiency and cost to turn the compressor (nearly zero with a turbo). So if the engine makes 320 at a high level of efficiency and you add 1 bar while maintaining that level of efficiency, you make 640. I believe the laws of physics govern this reliably. This is how they are able to rate fuel pumps as "capable of supporting X hp." I don't believe there is any way around this.

Can anyone explain how they produce numbers exceeding this ratio?