I don't know how much plainer I can state it. For a given area inside a tube, you will have a certain pressure drop when you flow mass through it. Higher flows result in higher pressures, and this is described as a square function. With large areas and low flows, it appears linear, but at higher flows, the pressure builds to the square of the airflow. A doubling of airflow will result in quadrupling the backpressure. This effect is most obvious with a significant restriction in place, such as a throttle plate, but you will see smaller restrictions exhibit this at higher airflows, such as across valves, through turbines and wastegates, intercoolers and such. All of this will prevent you from making the theoretical power Pyro is referring to.
Maybe you can explain to me how flow through an orifice is somehow different and non-existent in an engine..