Take a look at this post
http://www.trailmanorowners.com/foru...0&postcount=80
(#80 in the thread), and click the link for KN Filters. If I understand what I am seeing, my reaction is "Huh? Why should I do this?" The horsepower and torque gains are very small. And at reasonable RPMs, where you don't mind running your engine for hours at a time, they are even smaller.
Bill