Airbox or open filter for 85cc shifter?

[andy graham]

I know this question can be like throwing gas on a fire, but thought Id throw it out there one more time to see what comes back. Please be specific as to what airbox or what open filter is preferred. Thanks, Andy

[Greg Lindahl]

Unless proof is provided, most comments are opinions and should be understood as such.
My OPINION is that there's very little difference, if any, in performance between foam, cloth (K&N style) and foam within a three open hole standard plastic airbox.
My OPINION is that an oiled foam filter cleans incoming air better than the cloth style.
TEST: Note that you can see through a cloth filter held up to light and not through a foam filter. If you can see through a filter, particles can (?) get through. However, this runs counter to the very large number of users of cloth filters at all levels of motorsport.
YMMV

[Michael Taksa]

Unles required by rules don't run the airbox K & N filter all the way http://www.knfilters.com/racing/kart.htm