Searched, all I found was velocity stacks in intake manifolds.

My question is do velocity stacks in air filters really help that much? I can see how it helps with smooth flow but is that really true? Only filter I have seen the velocity stack on is Apex'i and Buschur. Just about all the other ones dont have it.

 

Gimmick a VSR is supposed to increase the velocity of the air into the engine using the runners. What happens is they start somewhat big and then decrease size slowly thus producing increase in velocity and thus more air into the combustion chamber. There is usually a trade off on these designs generally in the low RPM speed area where there isn't that much air being flowed through the head.

Air filters do the exact opposite of a VSR they slow down air flow. The cone on Apexi's filter seems to be used more for the purposes of reducing turbulence than really increasing intake velocity.