So Now That K&N, BMC And DNA Are Available???

[Monstaman]

... which one has proven to be the better bet?? anyone from in industry have knowledge or have any of you Tardis riders experienced good bad or otherwise?

Gonna get a filter and wonna make the right choice, I read somewhere that one of the filters didn't seal well due ti hard rubber?

[wjn]

Originally Posted by Monstaman

... which one has proven to be the better bet?? anyone from in industry have knowledge or have any of you Tardis riders experienced good bad or otherwise?

Gonna get a filter and wonna make the right choice, I read somewhere that one of the filters didn't seal well due ti hard rubber?

Cheapest and best for a short period is the standard paper air filter. (On any vehicle). Depending on the circumstances (dust etc.) after 1000 - 5000 km's you have to change for optimal performance.

This is where after market (K&N / BMC) comes in. You can clean them and reuse. Obviously you can buy several standard air filters (more than 10 or so) for one of these reusable air filters. Remember to take the costs of cleaning agent & oil in account, which you should buy also for K&N / BMC.

[GMP]

They are all the same basic material. I can tell you that the K&N fits perfect, the rubber is flexible and seals well. I would prefer the Amsoil filter or a high flow foam filter like a Twin Air to pleated gauze, but none are available yet.

[Dallara]

I hope I am not going to step on too many toes here, but when it comes to air filters what you choose all depends on what you're looking for...

First and foremost - and here's where I am going to get into trouble with some - is that paper is a terrible air filtration medium. Sure, it's cheap and easy to make, but it is very inconsistent in porosity and has horrible problems with water even when it's treated to resist it. It's flow rate is poor even when new, and worse as it gets dirty, not to mention it's tendency to get brittle with age...

Worst of all, get it nice and wet and it swells up and damn near stops flowing air altogether. And it doesn't recover when it dries out... Once it's been wet it's toast. Some will claim otherwise, but there are numerous tests that bear this out, and even with the very best brand paper filters.

Paper's lousy filtration qualities are why you are seeing them used less and less in A/C filters and power equipment.

But again, it does get used a lot because it is cheap and easy to make.

The dirtier the environment, the better it is to go with oiled foam. Foam flows well, even when quite saturated with dirt, and thanks to intake pulses it even has a slight tendency toward a form of self-cleaning. It can often be far, far better than oiled gauze, and is certainly way, way, w-a-y better than paper.

It is difficult, though, to make a foam filter "inside out" like the filter arrangement on the Hypermotard, so it may be a while before you see foam filters for them, if ever. UNI is probably your best bet if you want to see someone make a foam filter for the Hyper, and the best way to get them to make one is to contact them at http://www.unifilter.com/contact.html That's how they got to be making so many filters for vintage motocross bikes...

For street use, however, gauze is great stuff. It does a great job of filtration, particularly when oiled... And it is washable and cleanable. It also is completely resistant to water when oiled, and tends to shed water. What water it doesn't shed and does pass through the filter is easily handled by the engine just as it handles water vapor and condensation in the intake tract often at start-up. If it's not oiled it does tend to soak up water, but even when it does it still filters well and flows lots of air. and once it dries out it's as good as new.

Gauze also has a neat tendency to straighten and smooth airflow, which is why so many people like it for "pod" style filters... It works almost like a little airbox.

And it even flows more when it's dry, which is how we used to use gauze filters on production road racers where we were required to run air filters in the stock airboxes. It doesn't filter as well when it's dry, but that wasn't a concern for short sprint races at road courses.

Any oiled filter has one major drawback, however...

If you have a fuel injection system that has a wire-type mass airflow sensor (often called an intake MAF or MAP sensor) then the oil out of the filter can coat the wire over time, and collect super fine particles over the same time, and finally increase the amount of current needed to heat the wire that it gives false readings of an MAF sensor failure and also cause the fuel injection system to improperly meter fuel. This is rare, however, if the filter is PROPERLY oiled...

And therein lies the rub - most people over-oil the filter when they clean it and re-oil it. This is definitely one of those times where more is NOT better - less is. When over-oiled the gauze filters pass a lot of oil vapor into the intake tract, and as such can quickly coat the MAF sensor wire and cause problems.

It really takes VERY little oil to properly oil a gauze-type filter, and it is far better to err on the side of too little than too much. You can always add a bit more oil if you need to.

If you don't think that oiled gauze is the filter medium of choice for high-performance pavement-only vehicles then just take a look in the airboxes of Formula 1 and Indy Car airboxes... What will you find?

Oiled gauze.

As far as which brand is best - K&N, BMC, DNA, etc. - they are all pretty damn good. I have used all three of those specifically named, and honestly could not tell any real difference between them. I had a BMC in my BMW, and I have a DNA in my Ducati, along with a K&N in one of my Kawasaki's. I run oiled foam in my Kawasaki KLR, though, because it is often used off-road.

IMHO, you should use an oiled gauze filter on a street bike, and you won't go wrong with any of the major brands. Just remember not to over-oil it if you clean it.

Just my two cents... YMMV.

Hope some of it helps.

Dallara

[unfast1]

Originally Posted by Dallara

I hope I am not going to step on too many toes here, but when it comes to air filters what you choose all depends on what you're looking for...

First and foremost - and here's where I am going to get into trouble with some - is that paper is a terrible air filtration medium. Sure, it's cheap and easy to make, but it is very inconsistent in porosity and has horrible problems with water even when it's treated to resist it. It's flow rate is poor even when new, and worse as it gets dirty, not to mention it's tendency to get brittle with age...

Worst of all, get it nice and wet and it swells up and damn near stops flowing air altogether. And it doesn't recover when it dries out... Once it's been wet it's toast. Some will claim otherwise, but there are numerous tests that bear this out, and even with the very best brand paper filters.

Paper's lousy filtration qualities are why you are seeing them used less and less in A/C filters and power equipment.

But again, it does get used a lot because it is cheap and easy to make.

The dirtier the environment, the better it is to go with oiled foam. Foam flows well, even when quite saturated with dirt, and thanks to intake pulses it even has a slight tendency toward a form of self-cleaning. It can often be far, far better than oiled gauze, and is certainly way, way, w-a-y better than paper.

It is difficult, though, to make a foam filter "inside out" like the filter arrangement on the Hypermotard, so it may be a while before you see foam filters for them, if ever. UNI is probably your best bet if you want to see someone make a foam filter for the Hyper, and the best way to get them to make one is to contact them at http://www.unifilter.com/contact.html That's how they got to be making so many filters for vintage motocross bikes...

For street use, however, gauze is great stuff. It does a great job of filtration, particularly when oiled... And it is washable and cleanable. It also is completely resistant to water when oiled, and tends to shed water. What water it doesn't shed and does pass through the filter is easily handled by the engine just as it handles water vapor and condensation in the intake tract often at start-up. If it's not oiled it does tend to soak up water, but even when it does it still filters well and flows lots of air. and once it dries out it's as good as new.

Gauze also has a neat tendency to straighten and smooth airflow, which is why so many people like it for "pod" style filters... It works almost like a little airbox.

And it even flows more when it's dry, which is how we used to use gauze filters on production road racers where we were required to run air filters in the stock airboxes. It doesn't filter as well when it's dry, but that wasn't a concern for short sprint races at road courses.

Any oiled filter has one major drawback, however...

If you have a fuel injection system that has a wire-type mass airflow sensor (often called an intake MAF or MAP sensor) then the oil out of the filter can coat the wire over time, and collect super fine particles over the same time, and finally increase the amount of current needed to heat the wire that it gives false readings of an MAF sensor failure and also cause the fuel injection system to improperly meter fuel. This is rare, however, if the filter is PROPERLY oiled...

And therein lies the rub - most people over-oil the filter when they clean it and re-oil it. This is definitely one of those times where more is NOT better - less is. When over-oiled the gauze filters pass a lot of oil vapor into the intake tract, and as such can quickly coat the MAF sensor wire and cause problems.

It really takes VERY little oil to properly oil a gauze-type filter, and it is far better to err on the side of too little than too much. You can always add a bit more oil if you need to.

If you don't think that oiled gauze is the filter medium of choice for high-performance pavement-only vehicles then just take a look in the airboxes of Formula 1 and Indy Car airboxes... What will you find?

Oiled gauze.

As far as which brand is best - K&N, BMC, DNA, etc. - they are all pretty damn good. I have used all three of those specifically named, and honestly could not tell any real difference between them. I had a BMC in my BMW, and I have a DNA in my Ducati, along with a K&N in one of my Kawasaki's. I run oiled foam in my Kawasaki KLR, though, because it is often used off-road.

IMHO, you should use an oiled gauze filter on a street bike, and you won't go wrong with any of the major brands. Just remember not to over-oil it if you clean it.

Just my two cents... YMMV.

Hope some of it helps.

Dallara

Damn good write up. Learned something new today.

Thanks...

[dukepilot]

Dallara, nice write up! Possibly an additional option is a dry synthetic fiber filter. These have have shown to provide excellent filtration while maintaining good flow. More info here... http://www.mkiv.com/techarticles/filters_test/2/

Next time I have my K&N Beast R filters off I'm going to measure them to see if I can find a Fujita/Apexi dry synthetic fiber filter with a funnel top. The funnel top supposedly increases air velocity and helps spiral the flow of the air into the intake. The funnel top is similar in concept to the dimpled airbox lid used on Buell XB's. They are available in many sizes so I hope I can find one that fits.

Originally Posted by Dallara

I hope I am not going to step on too many toes here, but when it comes to air filters what you choose all depends on what you're looking for...

First and foremost - and here's where I am going to get into trouble with some - is that paper is a terrible air filtration medium. Sure, it's cheap and easy to make, but it is very inconsistent in porosity and has horrible problems with water even when it's treated to resist it. It's flow rate is poor even when new, and worse as it gets dirty, not to mention it's tendency to get brittle with age...

Worst of all, get it nice and wet and it swells up and damn near stops flowing air altogether. And it doesn't recover when it dries out... Once it's been wet it's toast. Some will claim otherwise, but there are numerous tests that bear this out, and even with the very best brand paper filters.

Paper's lousy filtration qualities are why you are seeing them used less and less in A/C filters and power equipment.

But again, it does get used a lot because it is cheap and easy to make.

The dirtier the environment, the better it is to go with oiled foam. Foam flows well, even when quite saturated with dirt, and thanks to intake pulses it even has a slight tendency toward a form of self-cleaning. It can often be far, far better than oiled gauze, and is certainly way, way, w-a-y better than paper.

It is difficult, though, to make a foam filter "inside out" like the filter arrangement on the Hypermotard, so it may be a while before you see foam filters for them, if ever. UNI is probably your best bet if you want to see someone make a foam filter for the Hyper, and the best way to get them to make one is to contact them at http://www.unifilter.com/contact.html That's how they got to be making so many filters for vintage motocross bikes...

For street use, however, gauze is great stuff. It does a great job of filtration, particularly when oiled... And it is washable and cleanable. It also is completely resistant to water when oiled, and tends to shed water. What water it doesn't shed and does pass through the filter is easily handled by the engine just as it handles water vapor and condensation in the intake tract often at start-up. If it's not oiled it does tend to soak up water, but even when it does it still filters well and flows lots of air. and once it dries out it's as good as new.

Gauze also has a neat tendency to straighten and smooth airflow, which is why so many people like it for "pod" style filters... It works almost like a little airbox.

And it even flows more when it's dry, which is how we used to use gauze filters on production road racers where we were required to run air filters in the stock airboxes. It doesn't filter as well when it's dry, but that wasn't a concern for short sprint races at road courses.

Any oiled filter has one major drawback, however...

If you have a fuel injection system that has a wire-type mass airflow sensor (often called an intake MAF or MAP sensor) then the oil out of the filter can coat the wire over time, and collect super fine particles over the same time, and finally increase the amount of current needed to heat the wire that it gives false readings of an MAF sensor failure and also cause the fuel injection system to improperly meter fuel. This is rare, however, if the filter is PROPERLY oiled...

And therein lies the rub - most people over-oil the filter when they clean it and re-oil it. This is definitely one of those times where more is NOT better - less is. When over-oiled the gauze filters pass a lot of oil vapor into the intake tract, and as such can quickly coat the MAF sensor wire and cause problems.

It really takes VERY little oil to properly oil a gauze-type filter, and it is far better to err on the side of too little than too much. You can always add a bit more oil if you need to.

If you don't think that oiled gauze is the filter medium of choice for high-performance pavement-only vehicles then just take a look in the airboxes of Formula 1 and Indy Car airboxes... What will you find?

Oiled gauze.

As far as which brand is best - K&N, BMC, DNA, etc. - they are all pretty damn good. I have used all three of those specifically named, and honestly could not tell any real difference between them. I had a BMC in my BMW, and I have a DNA in my Ducati, along with a K&N in one of my Kawasaki's. I run oiled foam in my Kawasaki KLR, though, because it is often used off-road.

IMHO, you should use an oiled gauze filter on a street bike, and you won't go wrong with any of the major brands. Just remember not to over-oil it if you clean it.

Just my two cents... YMMV.

Hope some of it helps.

Dallara

[Abarth]

@Dallara:
Great write up.

I was thinking of a Pipercross filter but I'm not sure yet.
It's this one: http://www.pipercross.net/motorcycle...sp?m1=6&m2=273
Has anyone here ever used a Pipercross filter on their bike? I had one on my previous car and it worked really well.
Throttle response was much better than with the stock filter and it was easy to clean as well.

[Dallara]

Duke Pilot - Thanks for the kind words, and too cool on the Apexi filters. I'd never heard of those before, and it seems they are damn sure worth looking into. Thanks, and please let us know if Apexi has any that will work with the "Beast" intake rig. Wonder if Chris at CA Cycleworks has talked with them about supplying the filters for his Hypermotard large capacity fuel tank kit coming up?

Sure would be nice to not have to worry about ever oiling the filter and getting the amount of oil right...


Abarth - Thanks to you, too, for the kind complments. Also too cool on you showing us all a foam-type filter for the Hypermotard. I had no idea anyone made one, and for certain conditions one of those would be best. Coming from dirt bikes I really like foam filters as they tend to work well and are pretty foolproof in many ways. If properly designed they can flow a ton of air, too. Thanks!

Seems like Hyper riders are getting more and more choices for air filter elements, and that can only be a good thing!

Dallara

[08hyper]

Danm Dallara, you sure like to type! LOL, good right up!

But back to Monstaman question, I have the BMC filter on my Hyper, because at the time, thats all that was available, I use K&N on my other street bikes, I have not seen the DNA filter yet, but are all the same basic construction, cotton gauze media, with a light oil.

Between the BMC & K&N, the only difference I see is that the K&N has a softer rubber compound, and (maybe) could seal a tad better at the edges, again maybe.

I have been using K&N filters for YEARS, both in trucks, autos & bikes, and have never had an engine failure from dirt, What I can tell you is that the
oiled cotton gauze type filters DO NOT filter as well as a HIGH QUALITY paper or some synthetic dry fibers, for the ULTRA FINE particles. But generally will out flow them, back in the day, K&N were the best for flow, not for the filtering, it was a trade off, but the good news was that the dirtier the K&N filter got, the BETTER the filtration was, and it still would outflow a new paper filter.


But like I said after years of use, the ultra fine particials that passed thru the K&N filter dosen't seem to have effected any of my engines, upon tear down inspections, pistons & bores were in GREAT shape! Aloha Alex

PS: It does seem like to me there are a lot of NEW air filter companies that could be as good or "better" than the performance standard "K&N"

[lelenb]

I too have the BMC and I would not buy one again. The seal has a flexible plastic that is way too hard to seal properly so I made neoprene gaskets for my airbox and lid. Second the BMC is exactly the same length as the stock paper filter which sounds right but is too long in the real world. Because the paper filter has a soft foam seal it compresses and seals nicely. The flimsy lid on the Hyper does not exert much force so the filter does not compress and ends up being too long with a weak seal. My BMC even had a molding void in the seal ring that would allow dirt to pass through. I trimmed about 3mm off of the BMC's seal lip which removed the defect void and made the filter the correct length. I have pictures some where.

I am going to get the TPO's in the near future.