[Christ]

Originally Posted by Maestro

Yes, I'm afraid there is a flaw in your logic. Read carefully. What I'm saying is that with reduced restriction elsewhere in the intake, you're now flowing the same amount of air at a lower throttle opening, so nothing really changes.

This is easily visualized if you take it to the extremes. Imaging blocking your intake prior to the throttle body with a plate with a 1/2" hole in it. Imagining you could even support the engine with such a hole, you would need to open your throttle very far to reach the same airflow you would have had without the plate at a smaller throttle opening, however once you open the throttle to achieve the same flow, everything is the same. It works the same in reverse with less restrictions instead of more.

To oversimplify the concept - The throttle plate is the single largest restriction in your intake system. Excluding small gains in flow velocity from smoothing pipes, and only adhering to basic flow principles, intake mods will only work at or near WOT because of this.

That said, there are other sciences involved that can improve the VE of the engine, thus decreasing it's BSFC via reduced pumping losses. The amount of gain achieved at our levels of operation by such things is essentially non-existent, though, unless the pump itself (engine and auxiliary systems) is tuned as a whole for a specific desired effect.