Which is the ability of the cylinder to minimise it's pressure differential between the *Outside* and the *Inside* of the engine.
Everything is happening very, very fast when an engine is pumping, it's not like those gifs that illustrate how the four stroke cycle works. There are many factors that are affected but it all comes down to physics. Stuff, (Like air.) has mass. To get it moving needs energy. There is only limited energy available by air pressure which is a result of gravity. That pressure is a constant. (At any given altitude.) which means that the faster an engine runs the less time there is for air to be pushed into the combustion chamber/cylinder.
The thing is that by manipulation of the lengths and volumes of the inlet and exhaust tracts you can change the points at which and times at which the engine will have the best overall VE. Our experience is that short pipes, due to the harmonics, (Another area.) don't work with the 8V due to a number of factors within the engine design. If you go with something like the ipothesis design you can probably get it to work, sort of, but it won't work as well as it could unless you start playing with far more complex factors like cam timing and lift and tract sizes and volumes.