I installed the under the seat one and really has a difference in air flow and performance....I did it that because was the easiest way to try without going to a dynotune that is not available down hear , since then one noticeable thing is that my ass is being burn as consequence of the air inflow of the new filter.....with the old one didn't t notice this, and really I wrote on another post I go the feeling that vibrations are lowered ...that s my experience.