Air cleaner opinion

[taxfree4]

I hesitated to post that test because in the past, we had a member who seemed personally offended by any criticism of K&N. However, I thought that anyone thinking about switching might be interested as it shows why manufacturers don't install 'serviceable' oiled media filters on their vehicles.

The internet is full of K&N filter complaints. Most focus on two issues: damage to MAF sensors (which our GL1800s don't use) from the filter oil, and visual evidence in the intake tract that excess dirt is passing through. But those are mostly anecdotal stories. If you want precise data you often need to get out of the real world and into a controlled environment. To measure horsepower you connect to a dyno. To determine the condition of your oil you don't look at color of the dipstick, you send a sample to a lab.

That's what the 'Spicer' test did. Rather than analyze filters pulled from an engine, they ran an ISO 5011 test on 9 competing filters using a machine that flowed test dust (a specific mix of particle sizes) at a constant rate until the filter clogged. Clogging was defined as restriction causing a pressure drop of 10 IN-H2O.

The results showed a clear pattern. Two oiled filters (K&N and Uni) were compared with 7 traditional paper/syntyetic filters, like Purolator, Wix, and AC/Delco. The best filter ran 60 minutes and let .4 grams of dust through. The worst (K&N) only ran for 24 minutes and let 7 grams through. So the best filter passed .0067 grams of dust per minute, compared to .29 grams for the K&N. That's a ratio of over 43:1!

It's easy to see why more dirt gets through the K&N. It has only 29 pleats, while the Honda filter has 43, or 48% more. With significantly less surface area the K&N can only flow more air by having larger pores. And larger pores mean larger dust particles.

The less efficient filtration of oiled media filters is fairly well know. But the big surprise to me was that they clog up faster, which is possibly due to having less surface area. I used K&N and another oiled filter in the past. I didn't like the clean/dry/re-oil routine, but I believed the hype that they lasted longer, and considered one for the F6B since the filter change is such a chore. Now that I know conventional filters last longer (and filter better) there's no way I'll install a brand that needs to be serviced MORE frequently.

Sounds good on paper, again, when you have a "controlled" environment you can control the outcome, sort of like polls which used to reflect real opinion now they are conducted in specific locations for a specified outcome. Even the previous test mentioned stated, "A small temperature change or a small change in humidity can cause the mass of a paper filter to change by several grams." In essence in the real world, which has a dynamic atmosphere all this is arbitrary. Manufacturers don't put things like filters in because they are the best they can possibly manufacturer they are on there because the accountants agree that it is at the right price. Case in point, my brother worked for the largest Jeep dealership on the East Coast and he said in order to go from the standard dashboard to a leather dashboard on that vehicle it would have cost the manufacturer 50 cents more per vehicle, they didn't do it, it's an option. All the people I rode with used K&N, they still do, these are guys that do their own work on their bikes. All I know is I change them every time, don't reoil, and it costs me a little more money. The bike runs great, she breathes fine, and now with the Torq Loopz even better. A lid for every pot

[F6Dave]

Sounds good on paper, again, when you have a "controlled" environment you can control the outcome, sort of like polls which used to reflect real opinion now they are conducted in specific locations for a specified outcome. Even the previous test mentioned stated, "A small temperature change or a small change in humidity can cause the mass of a paper filter to change by several grams." In essence in the real world, which has a dynamic atmosphere all this is arbitrary. Manufacturers don't put things like filters in because they are the best they can possibly manufacturer they are on there because the accountants agree that it is at the right price. Case in point, my brother worked for the largest Jeep dealership on the East Coast and he said in order to go from the standard dashboard to a leather dashboard on that vehicle it would have cost the manufacturer 50 cents more per vehicle, they didn't do it, it's an option. All the people I rode with used K&N, they still do, these are guys that do their own work on their bikes. All I know is I change them every time, don't reoil, and it costs me a little more money. The bike runs great, she breathes fine, and now with the Torq Loopz even better. A lid for every pot

So that's the problem! The indoor temperature and humidity in that lab caused the K&N filter to let 43 TIMES MORE DIRT pass through than a paper filter. I'm sure that out there in the 'real world', a K&N works much better. Just make sure you don't ride indoors!

[taxfree4]

So that's the problem! The indoor temperature and humidity in that lab caused the K&N filter to let 43 TIMES MORE DIRT pass through than a paper filter. I'm sure that out there in the 'real world', a K&N works much better. Just make sure you don't ride indoors!

I can see why a "controlled" humidity and temperature made the paper filter run at optimal performance, if that what you set it at. Again, as stated ", "A small temperature change or a small change in humidity can cause the mass of a paper filter to change by several grams.." That's the legal disclaimer, the escape hatch. Did they run it through a variety of temps and humidities? I don't see that at all. What they did is get a number they were comfortable with and that was it. These are like epidemiologic studies, manufactured data presented to look like fact but are not gold standard. You would think Honda would publish these "facts" as their filter sales would go through the roof, K&N would have to find another business to go into. Maybe you should contact Honda and send them this breakthrough study, maybe they'll even put you in the commercial. I would say don't wait by the phone.