Increase the efficiency of the inlet to the blower increases the quality of the air.
While gross volume remains the same, you increase the density of the air.
Friction on the inlet essentially stretches the air. Think of a rubber band at rest. Take a section and measure it. Now, stretch that section.
The mass of the section remains the same, but the length increases, so the mass of rubber per linear inch decreases.
This is the effect of having any restriction (friction, bends, small diameter tubing, etc) upstream (before) the blower's rotors.
Sent from my local E85 station.