ME 109 wrote:
As Funbags used to say, wipe the filter box and looky see.
Well, he didn't say looky see. That was me.
I've run both and report less dust with a K+N.
I know my dust. Bulldust especially.
All objective testing proves otherwise. Not even K&N claims they filter as well as OEM.
My last test with a paper filter was 12 months ago. 1500 k trip over three days, 500 was dirt.
My airbox was dirty when I got back. I was surprised.
The testing I was speaking of is comparative, and objective. There are many examples available where different filter designs are tested side-by-side, on the road and in labs, both by private individuals and by various magazines, and I have never yet seen results which did not show pleated gauze as one of the best flowing filters and one of the worst filtering. In every test I've seen OEM filters are more restrictive, but better at filtering.
Personal anecdotes leave lots of unknowns. While they may appear convincing to that individual, if the person has not established any control for comparison, it's simply not meaningful.
20 years of oe and K+N and swapping back and forwards, same bike. Good enough for me. Anyway, I'll wear the engine out before the dust does.
It seems the testing relates entirely to filtrate passed thru the filter.
There doesn't seem to be any re: the effects of the filtrate on an engine's life, at least not that anyone has presented in these discussions. The presumption seems to be that an engine won't last with a K&N.
I'm a long term K&N user too and the bike has done 230K+ kms. Anecdotes might be weak science, but to those telling the story, it's usually compelling enough. My filter box is also reasonably clean.
All the tests I've seen show air flow is not remotely a problem and doesn't need improvement by aftermarket filters. Efficiency does vary but when you are trying to filter out particles of just a few microns however efficient the filter media is I would have thought another problem is how well they seal in the housing and how well that seal is maintained during use with heat and vibration. You could always tell with the round/clam shell type that they had been under compression when you took them out so I assume they seal well. Even still there there must be leaks around the breather tubes.
Info in the spiel re: the blue filter by Green...maybe an improvement over the red one?
• Pleat design: The filters have pleats that are parallel to the width. This makes the filter more rigid and stronger and reduces air leaks.
• Stainless steel mesh on both sides
• Custom Fitment Tabs (for square filters only). Plastic air-boxes can warp out of shape or even distort from the heat radiated from the engine. These tabs also benefit the filter by centering and aligning it in the air box, so the filter is evenly sealed.
chasbmw wrote:Aussie bull dust is very red and very fine, it's easy to see if your filter is letting any into your air chamber, carb etc etc.
No, it is not. It is easy to see if dust is getting in. It is not easy, or perhaps even possible, to see "if your filter is letting any into your air chamber." As BarryH pointed out, air can be getting around the filter. That's why dirt bikes grease the edges of their filters. It's messy, but effective. Different bikes can have other leaks as well.
