on many cars, just opening up the intake does wonders
on others auto manufacturers put it there for a reason, likely related to intake cavitation, pulse or scavenging of the intake.
it actually eliminates standing waves at a certain frequency(s).
http://www.phys.unsw.edu.au/jw/Helmholtz.html
http://www.physicsforums.com/showthread.php?t=546927
http://www.dinamoto.it/dinamoto/8_on...suonatore.html
Many cars do fine without them, as they are often for sound; but sometimes it has to do with resultant air flow too.
I didnt like how my car ran with a completely unrestricted intake(no filter), and felt it did better at low rpms with the OE airbox running a high flow filter over stock
until someone can sell me an intake I really am sure works I will wait and see how these early ones do out on the tracks and dynos.