Bonneville America Forums Forums Technical Forums Performance Mods air filters

Do different ones make a huge difference? If I switched from the stock filter to a K&N would it be a good thing to do?

Air box compared to no air box and pods is a noticable difference, I can't speak to the steps in between since I just got rid of my air box right off. I hear good things about the drop in Uni filter and removing the snorkle and drilling the bottom of the air box. Don't know how much it effects the performance but I'm sure someone who has will chime in.

I have recently gone the drill-the-bottom-of-a-UNI-and-the- airbox-way and it do make a huge difference from stock. I don't know how much I could actually gain from going from this setup to the freak for instance, but then again, I have never tried a bike with the freak. All I know is that it was worth it!

In my experience the K&N made a difference over the stock unit. Not a huge difference (like I expect the airbox eliminator systems make), maybe not even any more power but coupled with freer flowing exhausts the throttle response was much better so it feels like the bike runs better.

I got the stock K&N replacement filter.This seemed to make a good difference without the top snorkel or restrictor.Then I cut the bottom out of the air box and filter.This helped also,of course with rejetting.You can hear the difference when you first do it and feel it ,if you rejet.To me that is.I currently am considering doing away with the air box and going with the seperate filters.They all seem to think it makes a big difference that have done it.

You will notice a difference if you cut a hole in the bottom of the airbox and the filter, assuming all the snorkels have been removed. I cut the hole 1 1/4" and it made a difference. As to filters, the K&N or the UNI drop-in filters, in my opinion, the difference is negligible. You are changing a dry filter for an oil-coated filter. The "plus" is supposed to be that you save money on filters, but if you ride in a dusty environment like I do, the minus is the time and money spent on maintaining the wet filter. It needs to be cleaned, dried, and re-oiled correctly for it to work optimally. For me, it became a pia.
And, any change which increases your air intake may result in the need for rejetting the carbs so you're not running too lean, depending on the exhaust you have.

I ended up going back to the stock Triumph paper filter. I blow it out with compressed air occasionally, and change it during every oil change after I drill the hole in the bottom.....

Going with pods and eliminating the airbox is a whole 'nother ballgame.

I use the UNI filter and my understanding is that the UNI, lightly oiled, is less restrictive than the stock paper filter. I tried the UNI before rejeting and could tell a difference. The UNI made it clearer more fuel was needed in the mixture. After set up right, you might not notice the difference. I feel it helped and is worth it, especially since I don't want to drill the bottom out of my airbox.