That's true and depending on the intake, the height, length and width as well as what runner needed help changed.
340-2, if you have your vacuum cleaner on, just a open hose, the round part, and it is sucking up, let's say, smoke from the out door fire. You can see the vacuum hose sucking in the smoke.
We will call that the air and fuel for this moment.
How do you get the vacuum to pull the smoke in faster?
Put your finger in front of the hose opening.
Same idea with the intake runners.