[eddie]

$15,000+ worth of testing at the factory of a $285,000 machine on some of the more common air filters on the market.
I wish AC Delco made bike filters!!!

K&N Air Filter Review - Debunking the Myths (and why OEM is better)

(Reload the page if the goofy ads cover part of the charts.)

 

[yoitsemo]

That dirt intake graph is frightening.

 

[SCRBen]

No-one else sticking their head above the parapet?!

Oh well - at the risk of creating a long-running thread already repeated across most other forums I’ve looked at before......

I’ve seen that article before. Interestingly, K&N cite exactly the same ISO standard (5011?) as the one their filters are tested too, suggesting “...K&N air filters generally achieve overall filtration efficiency in the range of 96% - 99%. The fact that our air filters at times reach overall filtration efficiencies as high as 99% while maintaining high airflow is a testament to the quality and capabilities of our oil impregnated cotton air filter medium”.

https://www.knfilters.com/mobile/filter_facts.aspx

If we’re taking one ISO-standardised test as gospel, we have to take the other one too!

The above link also has further links for graphs to ‘independent’ K&N test results.

I’m not saying who’s right and who’s wrong, but who are you to believe? I’d like to see a similar test of the OEM filter.

The guy who wrote the pre-amble to the tests on @eddie ‘s link also sounds like he has a bit of a K&N-shaped grudge, to me (he even calls it a ‘crusade’). It’s just inaccurate to state aftermarket air cleaners can’t increase HP as well. My seat-of-the-pants dyno felt it after fitting my K&N. Not very accurate, I know, but Ivan also states air filters make the greater difference on our bikes than a pipe change. Indeed, K&N’s own dyno chart for the filter for our bike, shows a 7hp increase:

https://www.knfilters.com/dynocharts/RK-3940_dyno.pdf

Are they lying? That report author might say so. Have they fudged the dyno results? Atmospherics causing false readings? Maybe 1 or 2 hp, but not 7.

Sorry for the long post, but I’m on nights’ tonight, and bored.

I await the multiple scuds that will no doubt now come my way!
Ben

 

[eddie]

I look at it like this: K&N filters flow more air until they are very dirty, yes? More air with proper tuning can = more h.p.
Thing is, their filtration is weak at first until some dirt collects on the oil-treated gauze, effectively creating more dust/dirt trapping surface area.
Until then, more dirt passes through. To get good filtration, one has to allow it to "fail" as a filter for a while.
That's like really good novocaine at the dentist that starts working after the root canal.

"Bob is the oil guy" used to cite a mining operation that was spending something like $30,000 a month on air filters for their huge diesel dump trucks.
They needed something more economical to keep those $$$,$$$ engines running.

Each bank of the V engines had a primary & secondary filter.
So, they took one vehicle and measured the silicon content of used oil with the stock setup and then replaced
all of the filters with clean originals except one primary filter on one side of an engine. They installed a K&N there.
By the end of the day, that bank's secondary filter was clogged and the silicon content of the oil was sky high.
They went back to disposable paper filters.
Extreme testing in conditions a street bike should never see? Yes.
It's more like a time-compressed survey of what could happen in the long run, though.

A more real world example had a guy taping white double sided tape(?) inside his car's airbox for 2k miles using different filters
for a few cycles with new tape each time. A side-by-side comparison wasn't very complimentary to the K&N. That tape was dirty-dirty.

 

[srinath]

I'm also not going to be very scientific here, but I put 50K miles on 1 GS500 with a K&N, starting with ~8K and the deterioration in that bike @20K was significant - and I have put 8-20K on several others including my current one with stock air filters - and its significantly less wear. Significantly less oil use, and 20K was about where the K&N was actually beginning to make less power and less top speed showing enough wear to make even the enhanced air flow make less power.
And on a GS500 replacing the airbox with a K&N lunch box as we would call it makes for seriously good air flow.

 

[SCRBen]

They must offer a “million mile warranty” then because they know their filters do so little filtering that’ll they’ll never wear out and need replacing!! :grin2:

I notice their T&Cs don’t offer a new engine if their filter is insufficient...

I really would worry if I was one of these lads though......
Ben

 

[SCRBen]

Interestingly, the Two Bros Comp-V system is noted for a “direct air” option......

The filter element is K&N too. #justsaying
Ben

 

[Schu]

Interestingly, the Two Bros Comp-V system is noted for a “direct air” option......

The filter element is K&N too. #justsaying
Ben

I don't know about you Ben but I run my K&N with the OuterWear prefilter all the time. It keeps the little bugs from getting caught in the pleats. And probably helps with the overall effectiveness of the filter.

 

[SCRBen]

I don't know about you Ben but I run my K&N with the OuterWear prefilter all the time. It keeps the little bugs from getting caught in the pleats. And probably helps with the overall effectiveness of the filter.

Nope, not once. :laugh:
Ben

 

[eddie]

Once upon a time, I got bored and...
who am I kidding? I do goofy stuff like this for no reason on a daily basis.

Anyhow, I wanted to play around with the intake on my old 2004 XL1200R.
This was over 10 years ago, so I don't remember the exact filter #, but I found an auto air filter that was
2" thick, oval-ish and fit snugly against the backing plate of a HD Screaming Eagle airbox part quite nicely.
Those carbed Harleys had an arrangement where the filter was bolted to the carb backing plate(?)and had a threaded metal plate
to which one bolted the metal outer cover. Given the car filter was open and had no such provision, I carved out an oval
metal plate the size & shape of the filter and attached the metal cover mount from an old filter to that.
In order. from the carb mouth outward, I had:

Screaming Eagle backing plate.
Thicker car filter.
Home grown flat plate bolted to the SE backing plate, sandwiching the filter in between.
Finally, the stock outer cover bolted to the plate I made.

With this setup, the OEM outer cover was all but about 1/4" deep enough to protect the entire filter assembly.
As my bike had to live outside under a cover and occasionally got wet, I didn't want water intruding on the filter medium.
I ended up trading the bike before I sorted that bit out.
Thing is, it worked, offering a substantially larger filter area for air to go through, a better filter than the Screaming Eagle kit had
and replacements were available at most any auto parts store for WAY less than a K&N, stock or other m/c filter.

I'm trying to make something like this for the SCR in my head. I don't want to hack up my stock backing plate.
So, I'm watching eBay for a cheap used one and contemplating a suitable new outer cover.
Stay tuned, campers!

 

[SCRBen]

I'm trying to make something like this for the SCR in my head. I don't want to hack up my stock backing plate.
So, I'm watching eBay for a cheap used one and contemplating a suitable new outer cover.
Stay tuned, campers!

$160 too much?! :grin2: I’m sure I saw a cheaper one on there recently, but can’t find it now.....

I’m staying tuned, cos apparently I need a better filter! :grin2:

Presumably on your XL, that air filter you found was thicker than the SE one tho (hence you picked it)? Was it also more restrictive as well - did the bike run richer as a result? Or did the larger medium even it out? Having said that, it’d have been easier to change out the jet than changing fuelling maps on EFI bikes anyway (unless youre considering the reflash too?)

Colour me interested.
Ben

 

[eddie]

$160 too much?! :grin2: I’m sure I saw a cheaper one on there recently, but can’t find it now.....

I’m staying tuned, cos apparently I need a better filter! :grin2:

Presumably on your XL, that air filter you found was thicker than the SE one tho (hence you picked it)? Was it also more restrictive as well - did the bike run richer as a result? Or did the larger medium even it out? Having said that, it’d have been easier to change out the jet than changing fuelling maps on EFI bikes anyway (unless youre considering the reflash too?)
Colour me interested.
Ben

I'm looking for this part (photo of fiche).
Good guy price is $51.10USD. (+ new seals just because.)

It's crazy. The simple, uncomplicated outer airbox part is almost 3X as expensive as the precision formed inner piece.

The car filter was designed for a much larger displacement engine than the 1200 Harley. So, I didn't even consider it possibly being restrictive. The SE jet kit got me a different needle & main jet with a drill for the air hole in the slide for faster response. I went with my own #45 slow jet with about 1.75 turns out on the air screw and it didn't hiccup, cough or do anything but run great. A Harley shop tech took it for a ride and came back wanting to know what I'd changed? Seems every Screaming Eagle jet kit & pipe installation he'd done was never quite "there". They'd spit back through the carb a bit on part throttle acceleration. The bigger slow jet fixed that, I think. I went from there with no real changes. The plugs were a originally a bit discolored (rich) and new ones looked fine with the other filter.

 

[jobirobi]

It's crazy. The simple, uncomplicated outer airbox part is almost 3X as expensive as the precision formed inner piece.

It's probably a demand thing - when someone takes a spill, that cover is one of the most likely parts to need replacement. And maybe some noob modders wind up needing a replacement after their "MOAR AIR!!" hack goes wrong.

 

[Schu]

No-one else sticking their head above the parapet?!

Oh well - at the risk of creating a long-running thread already repeated across most other forums I’ve looked at before......

I’ve seen that article before. Interestingly, K&N cite exactly the same ISO standard (5011?) as the one their filters are tested too, suggesting “...K&N air filters generally achieve overall filtration efficiency in the range of 96% - 99%. The fact that our air filters at times reach overall filtration efficiencies as high as 99% while maintaining high airflow is a testament to the quality and capabilities of our oil impregnated cotton air filter medium”.

https://www.knfilters.com/mobile/filter_facts.aspx

If we’re taking one ISO-standardised test as gospel, we have to take the other one too!

The above link also has further links for graphs to ‘independent’ K&N test results.

I’m not saying who’s right and who’s wrong, but who are you to believe? I’d like to see a similar test of the OEM filter.

The guy who wrote the pre-amble to the tests on @eddie ‘s link also sounds like he has a bit of a K&N-shaped grudge, to me (he even calls it a ‘crusade’). It’s just inaccurate to state aftermarket air cleaners can’t increase HP as well. My seat-of-the-pants dyno felt it after fitting my K&N. Not very accurate, I know, but Ivan also states air filters make the greater difference on our bikes than a pipe change. Indeed, K&N’s own dyno chart for the filter for our bike, shows a 7hp increase:

https://www.knfilters.com/dynocharts/RK-3940_dyno.pdf

Are they lying? That report author might say so. Have they fudged the dyno results? Atmospherics causing false readings? Maybe 1 or 2 hp, but not 7.

Sorry for the long post, but I’m on nights’ tonight, and bored.

I await the multiple scuds that will no doubt now come my way!
Ben

As I see it, this issue of penetrating dust particles is more of a concern for those riding in extreme conditions like "following behind" a group of bikes down dusty gravel roads and two tracks. Probably more of a concern for the gray SCRs.

Ride Red!

 

[eddie]

As I see it, this issue of penetrating dust particles is more of a concern for those riding in extreme conditions like "following behind" a group of bikes down dusty gravel roads and two tracks. Probably more of a concern for the gray SCRs.

Ride Red!

Repurposed Honda slogan for those poor, unfortunate souls. >