205'd: Speaking of MotoLab, there he is now. Thanks. It's a weak spot on the DR and many guys don't even know it's in there. I should mention it more often. I don't like the K&N replacements. MotoLab has one by UNI that may be suitable, but I've never seen one up close. Since Rusty's idea works so well, I've never looked any further. Derek mentions the UP-123 may have less resistance than the filter used in my link. The filter we're talking about flows all the air under the slide diaphragm, as the slide rises and falls. If you're an aggressive rider, your slide is going up-n-down a LOT, moving a bunch of air and resistance will matter. I'm retired and don't care to get hurt (again), so I'm very smooth on the throttle; my slide doesn't need a high air flow capacity. Your choice and now you have a little more information.