Bernoulli and 350 ft/s, 146 cfm/in²

Here's an equivalent without the math. Let's say you're racing a 3200 lb car with a 400 hp engine. You can get about 116 mph in the quarter mile, but the theoretical limit is 130 mph. The 1.012 psi on the flow bench is like the 400 hp, it's all the power there is. The 3200 lb car is like the density of the air in the port. It's the mass that's being pushed. There is a limit to how fast 400 hp can push a 3200 lb car just like there's a limit to how fast 1.012 psi can push air with a density of 0.0764 lbm/ft3. Lighten the car and it can go faster on 400 hp. Reduce the air density and it can go faster than 350 ft/s with 1.012 psi of pressure drop. The 3200 lb car will never get to the 130 mph theoretical limit just like the 0.0764 air will never get to the 350 ft/s theoretical limit.