Filters r pretty much useless if u don't open up ur airbox in my opion. K&N flow more but lets more dirt in than the others, if u ave a K&N it should have an outwears on it. I'm waiting for K&N to come out a airfilter cuz i don't want the Alba kit, i rather have it made for my machine by the manufaturer. You will get some good power from taking off the airbox lid, but u need to rejet and jetting depends on elevation.
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