well i have tried the kn filter but i got case of the 51515's off the site and they get very little time between changes and never had a problem.
i have a case of the 51515r's which have a thicker case but i don't like useing them because the element is to corse. i will get to the bottom of this, it's not rocket science either the filter was thin which i doubt or i buzzed the motor before the oil was up to temp. or the it's valve like everybody seem to think