Air Filters: Do They Really Make A Difference?

[Guest klinquist]

Common sense tells us that more air flow = more power... but do a K&N or BMC filter really make any difference on the VFR (specifically 6th gen)?

I'm also a BMW (car) enthusiast and cold air intakes tend to give you almost no horsepower, even when paired with other mods. Of course, I know there are other cars out there that do get power.

The stock air filter looks pretty good. The K&N seems to have a smaller area. The BMC looks to be about OEM-sized. I don't like cleaning and re-oiling filters - I'd rather spend $25-30 on an OEM filter and replace it every 15k miles than re-oil a $75 filter assuming similar performance.

I just installed a PC3+coyze and have gutted cans on their way to me - just wondering if an air filter will 'complete the system' or if it's 'not really necessary'.

Thanks!

[Beck]

Shouldn't you also consider increasing the volume of gasoline injected into the induction system to make power? It's not just all additional airflow that produces more power. Otherwise you have an over-lean condition that could burn up things inside your motor. I think there is a need to add higher volume fuel pumps and injectors to really push the power up. In addition to reprogramming the PGMFI.

Beck

95 VFR

[BusyLittleShop]

BMC makes a difference because it sports more area than a K&N... but BMC may require a change in

maps whereas the K&N don't... thats why K&N area is smaller than a BMC... no change required...

BMC

K&N

BTW you're lucky to have the choice of an aftermarket filter... no one makes one for the RC45... I had

to make my own out of parts of an K&N...

[coderighter]

There doesn't seem to be a gain with the K&N or BMC filter. K&N actually makes the element smaller so that it flows the same as OEM "so that you don't have to re-tune to use it". The BMC actually has a larger element than the K&N but I don't think the quality is as good as the K&N. I have the BMC and had to "fix-it" to fit right.

The main reason to buy them is because the Honda filter will run you about $50. You can find a K&N for around $45 and the BMC for about $60, both will last forever.

[Guest]

The main reason to buy them is because the Honda filter will run you about $50. You can find a K&N for around $45 and the BMC for about $60, both will last forever.

Gotcha. Thanks for the info.

Cheapest I can find the BMC is about $80 shipped. I got my last OEM filter for $30 from servicehonda IIRC (while I was ordering other things, so I don't know the standalone shipped price).

[blkrabit]

Hey BLS:

Nice try eliciting sympathy for the RC45 owners out there...if you can't handle that beauty, give it to me!

[enzed_viffer]

The main reason to buy them is because the Honda filter will run you about $50. You can find a K&N for around $45 and the BMC for about $60, both will last forever.

That's why I've had Unifilters on my last four bikes (that, and the fact the local Honda dealers don't seem to have ANY parts in stock, ever). There wasn't a Uni available for the VF500, but a custom auto filter maker made one for it. Then I went to replace the VFR750's with one, and found one was already fitted! There wasn't one available for the VTR either, so I made one, and used the left-over foam to make one for the VFR800.

[Guest]

I have a Pipercross one from the last two weeks... and I'm very happy of it, especially for accelaration :happy:

actually I'm waiting the biannual revision (dunno in USA, in UK it's the MOT), when passed, I'll try experiments with supplemantary resistor on the IAT (maybe about 1 kohm would do the job) to enrich a little

theoretically, it would increase the overall fuel curve... when I'll do the mod, I'll share impressions

I don't feel necessity for a PWC, 'cause my exhaust it's perfectly tuned for my bike (curiously it is for a Cbr 600 :dry: )... no annoying 4/5000 rpm's hole

perhaps I'll want the PWC when I'll do the Big Bore :biggrin:

[Beck]

I just bought an OEM Honda filter for my 4th gen AGAIN!....after considering for years to try out a Uni or a K&N...

Now that I see the minimal power gains and price difference I don't really mind being a lazy bum and just keep using the OEM stuff..Same goes for coolant, and oil filters....and regular, plain ole bicycle pump/gas station air for my tires :biggrin:

[Guest]

by all accounts on actual tests run by mechanics and performance specialists on just this kind of thing, initally the expencive air cleaners like KB and what not, do increase performance. However that is just for about the first 1000 miles, after which they not perform as well as the OEM filters, they get too cloged too quicky, so unless you are planning on cleaning your airfilter every thousand miles or so. Just keep getting the OEM filters.

[spud786]

The main reason to buy them is because the Honda filter will run you about $50. You can find a K&N for around $45 and the BMC for about $60, both will last forever.

Gotcha. Thanks for the info.

Cheapest I can find the BMC is about $80 shipped. I got my last OEM filter for $30 from servicehonda IIRC (while I was ordering other things, so I don't know the standalone shipped price).

$30 is an outstanding price, but they are normally $50, prices have gone up recently, they are getting closer to $60 now. If you can stay under $40, thats still good compared to most other areas.

[HispanicSlammer]

K&N has a more efficient matierial for filter, hower the total area of the filter media is smaller so its a wash. However economically mine has paid for itself 3 or 4 times over, cleaning and reoiling is a snap and I dont have to waste my time taking a trip or spending time ordering a new oem one when it gets clogged up. Paper is fine but until sombody figures out a way to reuse it well enough the K&N is worth the money.

[soichiro]

K&N has a more efficient matierial for filter, hower the total area of the filter media is smaller so its a wash. However economically mine has paid for itself 3 or 4 times over, cleaning and reoiling is a snap and I dont have to waste my time taking a trip or spending time ordering a new oem one when it gets clogged up. Paper is fine but until sombody figures out a way to reuse it well enough the K&N is worth the money.

I use a K&N in every engine I own. Just for the money savings. Your noy going to get more power even if you run no air filter. If you do it will be so minor there is no diffirence.

Fact. K&N filters flow better once they get a little dirty.

LIke I said, it just saves money. A stock filter is $45, a K&N is $50 and you never have to buy another, pretty simple math, just dont expect 10 horsepower. Maybe more like a 1/10th of a HP.

I have never seen a dyno sheet from just an air filter that did much. My wifes car does seem to breath a lot better at high rpm's. More air with no more fuel equals nothing.

[Guest]

K&N has a more efficient matierial for filter, hower the total area of the filter media is smaller so its a wash. However economically mine has paid for itself 3 or 4 times over, cleaning and reoiling is a snap and I dont have to waste my time taking a trip or spending time ordering a new oem one when it gets clogged up. Paper is fine but until sombody figures out a way to reuse it well enough the K&N is worth the money.

I use a K&N in every engine I own. Just for the money savings. Your noy going to get more power even if you run no air filter. If you do it will be so minor there is no diffirence.

Fact. K&N filters flow better once they get a little dirty.

LIke I said, it just saves money. A stock filter is $45, a K&N is $50 and you never have to buy another, pretty simple math, just dont expect 10 horsepower. Maybe more like a 1/10th of a HP.

I have never seen a dyno sheet from just an air filter that did much. My wifes car does seem to breath a lot better at high rpm's. More air with no more fuel equals nothing.

Yes,I almost agree with your statement; more air with no more fuel equals nothing. Sometimes it equals less,because it will lean out the A/F ratio

and create an overly lean condition,like one of the guys already mentioned. However, I think you guys are forgetting about the oxygen

sensors in todays cars and bikes. If you put in a new air filter that breathes better the engine will sense a lean condition and adjust

or increase the amount of fuel it delivers. So in some ways the system will self adjust to the new air filter and make some additional power.

[Auspanglish]

I switched to a K&N baed on the (obvious) long term savings... didn't notice any power increase... if there was any it is unperceivable by a mere human.

BTW, any "How-tos" on here regarding how to clean a K&N and how to impregnate one and with what type of oil? I am refering to alternative detergents and oils to the K&N brand...

[Guest]

I went to an "UNI" foam air filter and did notice an increase in performance. I could have also seen the same change by installing a new/clean OEM... the old one was very dirty.

The foam filters do allow for more airflow, but you have to clean/service them regularly.

[Guest]

by all accounts on actual tests run by mechanics and performance specialists on just this kind of thing, initally the expencive air cleaners like KB and what not, do increase performance. However that is just for about the first 1000 miles, after which they not perform as well as the OEM filters, they get too cloged too quicky, so unless you are planning on cleaning your airfilter every thousand miles or so. Just keep getting the OEM filters.

Got any links to support this? I would be interested to see how they were done.

Action

Edit, I did find this test Filter test but I didn't think its that conclusive.

[Monk]

I switched to a K&N baed on the (obvious) long term savings... didn't notice any power increase... if there was any it is unperceivable by a mere human.

BTW, any "How-tos" on here regarding how to clean a K&N and how to impregnate one and with what type of oil? I am refering to alternative detergents and oils to the K&N brand...

I've used 401 spray for my cleaner.... Always run cool water from the inside out, no hard streams(that can move the gause(not foam), and cause un-uniform openings in the filter).

As far as re-oiling,any light weight spray oil should work, but I don't know for sure..... I use the K&N oil.......

One more thing .... Let it dry before re-oiling.........

[Jon28]

I love my BMC filter....quality is just as good as any K&N I have seen. And no I did not scientifically prove that theory so don't ask me;-) It fit perfect and it's simple and easy to clean. If you don't like that idea, shell out $40 a pop on the OEM that won't last too long....

[Guest]

Just a cursory glance on ePay returns this page, with ATV Parts Unlimited selling new K & N's for the 6th gen @ $55.00 shipped.

http://shop.ebay.com/?_from=R40&_trksi...-All-Categories

You can prolly shave that figure a bit with a little research. I use the K & N Filter Cleaner and Filter Oil which work great. Once you have the filter out, it's not even a 10-minute job to clean and re-oil it.

[coderighter]

I have a BMC filter, same design (cotton) as K&N. Knowing what I know now, not sure I would do it again.

http://www.bobistheoilguy.com/index.php?op...6&Itemid=76

If you search the web, there's a lot of sources that contend the same thing. A lot of sports car forum,s people are ditching the cotton filters for synthetic fiber filter, some of which are washable. Fram (I know), AFE, AEM, and Amsoil (I know) all offer them but none for the any year VFR. They all seem to use a version of material that was first used by the Donaldson Company, which by the way, made my wet and dry vac filter that works outstanding. I've used the vac in the house on sheetrock dust with never a hint of dust out the exhaust.

The standard that is used to rate filters abilty to filter, is ISO 5011. That standard lets you choose between "fine" or "course". K&N chooses to use the "course". They claim 96% to 99% using "course" Translation, it stops the rocks from getting in. Alot of the new synthetic are claiming those same numbers using the "fine" test with similar flow numbers. They just need to be cleaned to more maintain those flow numbers. Most use soap and water, but none use any oil. They also tend to be thicker, app for app.

At least the BMC is suppose to offer more flow because of it's larger element size. The K&N was made with the smaller element to flow the same as the stock filter. K&N did this on purpose so that it could be used without any changes to the fuel mapping. Thats why most PC maps say "stock or aftermarket filter" Really all you gain is reuse, at the cost of extra dirt. The extra dirt over time is going to lower power, IMO.

All this being said, I've used K&N filters for the last 25 years and will more than likely leave them in all the vehicles but my VFR. I have seen differant cotton gauze filter oils out there and I may do a little research and see if any are thicker/stickier.

For the VFR, I'm going to ditch the BMC filter after I come up with a way to adapt one of the new synthetic fiber filters. I'm leaning toward the Amsoil oil nano filter (I know, I know - the darkside).

[Guest]

From my experience, running a naturally aspirated engine works best with the stock filter.

We had a dyno day a few years ago and I tried a brand new K&N and got 168hp, 167ft.lb.

Just for shits and giggles I thought I'd try my new stock filter and to my suprise it went up to 170hp and 170ft. lbs.!

Then I took the air filter out all together and lost power! 163hp and 161ft. lbs.

All measurements were taken at the wheel and A/F ratios were measured as well.

I was running incredibly rich all day but the engine held it's A/F ratio for longer with the stock filter. It just happens that my efi wasn't able to cope properly with the added air flow passed the MAF. Thus, I was loosing power by running too rich from my MAF overcompensating. Sometimes I think we get all "horny" over marketing when the real fact is manufacturers spend millions getting these systems to work for us properly 99% of the time. Air boxes need the proper operating pressure above(and volume) and below the filter media to work correctly. Just like exhausts...., bigger is not always better. Headers are designed to efficiently "scavenge" the exhaust from the cylinders to promote effective detonation of the incoming charge. We also need to remember that our engines are just glorified air pumps... No matter what type of filter we use from stockings to marine foam, that engine turning at redline will only be able to swallow so much air. So unless you are using positive displacement i.e., turbo/supercharger, you really shouldn't be seeing any benefit to a "higher" flowing filter from your stock clean filter.

JMO

Jack

[Old School]

:offtopic: I have a K&N in my 83 and it is the same size as the oem but the point I em making is I have had my K&N filter for 20 years and a lot

of miles and after about 3rd or 4th cleaning I start saving money and I think it filters better, with oil it traps smaller particles and when you

do your first wash you will see all of that dirt come out and you will say OMG. And as for the hassle of cleaning, it is easy as said before just spray it

on let soak and spray off and let dry. The drying is the worse part LOL you have to let it dry.

Stephen

[Guest]

BMC makes a difference because it sports more area than a K&N... but BMC may require a change in

maps whereas the K&N don't... thats why K&N area is smaller than a BMC... no change required...

BMC

K&N

BTW you're lucky to have the choice of an aftermarket filter... no one makes one for the RC45... I had

to make my own out of parts of an K&N...

well he owns a rc 45 and complains about lack of air filters, some people just dont know they're born

lol

fantastic bike m8

[Guest]

i just buy the honda paper filter.i guess mine dont get real dirty since i have like 34,000 and im only on my 2nd filter.

i expect the honda dealer to not have any vfr parts so i always order them online.

[TimC]

I have a K&N in my 6th gen VFR. Bought it slightly used from a fellow VFRD member a couple years ago. I think it was a good deal for $30 or so.

I can't say it has any real performance benefits, but it's a relatively cheap and easy mod - and like HS said above, it's easy to clean and recharge. After 2 or 3 seasons you'll have started saving money over buying OEM filters, plus you're using less materials and producing less waste, which is good for the environment.