Since we're talking physics, here's some...
The very best measure we have as to how much air is filling the cylinders is MAP - Manifold Absolute Pressure.
On a N/A engine, the very best MAP that can possibly be achieved at WOT equals atmospheric pressure. (approx 101 kpa at sea level). That would represent 100% efficiency of the intake tract, something in practice, is almost impossible to achieve.
So, the next question becomes, how can we acheive a more efficient intake?
1. Draw in cooler, denser air. Anything that draws from outside the engine compartment will do this.
2. Draw in from a "high localized pressure point" in or around the car. Under the radiator shroud is good, the foglight grilles are good. Air IS being "rammed" there, and as such, local atmospheric pressure at inlet does indeed increase. (this can and has been measured).
3. Sharp bends in the flowpath. Any fluid, in any vessel, will show resistance to changes in flow direction. The sharper the bend, the worse it becomes. In-tract turbulence results, and flow efficiency drops.
4. Filter media. A finer filtering media will inherently restrict flow than a more open weave or porous design (for the very same reason as #3).
Now, and compare this to any other design on the market...The Vararam draws 100% outside air, draws from a very high pressure point at the exterior of the car, has no sharp bends in flowpath, and top it all off, has a pretty crappy filtration media.
You're damn right it's going to be one of the most efficient setups available.
The only commercially-available product that ever rivaled it was the original Halltech TRIC, and if it had a forward facing filter element, would probably still be top dog in terms of performance (but not water intrusion resistance)
The bottom line is anyone with scanning/logging software can easily test this themselves. If filter setup X is giving you 94kpa MAP at WOT @ 100mph, and filter setup V is giving you 98kpa under the same conditions...filter V is making you more power. Period. No ifs, ands, or buts about it.
No, none of them are pressurizing the intake....that's called boost..but the one that capitalizes on the 4 main things mentioned above, is more than likely gonna be the winner in terms of how much air actually does make it into the cylinder.
