K & N Air Filter

[sw_freak]

Hello group!

Stupid question. :a13: Does the K & N air filter for the '03 also fit the '04? I think it does but I want to be sure.

[racer1735]

Along the same lines, does installing a K&N lean-out the mixture (as it does on a carbureted bike), or does the ECU compensate for it?

[nm6r]

I ran a K&N and Staintunes on my 2004 with no further adjustments or adverse affects. The computer although lean with stock air filter and pipes maintains the same ratio.

The TurboCity fuel pressure regulator helps with the lean problem. They even bump up the pressure a bit more for K&N and/or aftermarket exhaust.

Ray
http://www.frontiernet.net/~st1300rider/smile04Bikerwheelie.gif

[g17]

I just replaced the stock filter with a k&n about 600 miles ago with no adjustments needed

[racer1735]

I went ahead and installed a K&N last night. Went to AutoZone and they ordered one for me and had to to me the next day. Figured I would be ahead to pay retail and have it quickly, rather than save maybe $8 on the internet, then pay shipping and still not have it for 5 days.

Gave me a good opportunity to open the airbox for the first time, as well. Very clean in there, just a bit of oil blow-by, which I cleaned up. Also took the time to wipe down (dust) the underside of the tank and the various hoses and bits around the airbox (I like a CLEAN bike, inside and out).

First impression is that the engine runs a tad smoother, but I'm guessing that's largely because the original filter was pretty dirty. I'll get a better idea after I take a weekend ride.

[BigBadblue]

Have you guys have read about how well K&N filters actually filter? They mainly only benefit top end horsepower and the way they do it is basic; larger pores for air to pass through. They simply do not filter as well as a paper or oiled foam filter. I saw a crude but effective test with an XR400, he put a thin film of white grease on the inside of his intake boot, oiled foam filter resulted in a nearly pristine coat of grease, K&N resulted in the grease film thoroughly coated with dirt. I value longevity over a couple of HP. Personally I would not purchase any used machine that has had a K&N run it for any length of time. IMHO
P.S.
Some good filter info http://www.oilsandlube.com/dustk&n.htm

[racer1735]

To each their own. But if you change your oil every 3,500 miles, keep the filter cleaned and oiled, you aren't going to kill your engine with one.

[txSTn]

I also installed a K&N recently. I have read all the pros and cons, but I was not greatly worried about the filtering aspect. However, once I got it in place, and the light bulb came on (duh!) I realized the ST pulls air from the inside of the filter to the outside - opposite of the norm. So, to wash this thing out, I will have to push the water through from the outside back to the inside, making it difficult to rinse completely, or maybe just more of a PITA. So, if I were to do it again, I would not. Just my $.02


Dub

[yoitsmatt!]

i used k&n's on my 4 stroke race bikes, i was really suprised to find out how much dirt actually ended up inside the air intake boot! and i washed and oiled them before every race, i see alot of my customers use them on cars and trucks also but they dont get oiled enough to actually work! the oil is so important that in the directions they say even if you dont have time to clean it you should re-oil the filer if it dries out, that being said they are a great quality product that is not maintenance free, proper cleaning takes 8 hours to air dry, then re-oiling ....im too lazy to put that much effort in to an air filter for a bike that wont miss 1 HP, but they do flow more air!

[nm6r]

The K&N will typically go 50k miles before cleaning and re-oiling. It's not that big of a deal. Dyno testing has shown a 6hp gain on an ST1300.

To the naysayers, it's not as simple as bigger pores allowing more air flow. It's a completely different filtration media. For example a cartridge filter on a swimming pool is actually fairly poor, not to mention the very finite life of the elements. A DE filter will trap 7 times finer dirt and debris, has a much larger load capacity and is renewed with every cleaning.

Bottm line, the K&N is a different media and doesn't have the fine metal screen surrounding it blocking air flow.

BTW, I've had mine on my ST for 20k miles and the airbox is immaculate.

Ray
http://www.frontiernet.net/~st1300rider/smile04Bikerwheelie.gif

[sw_freak]

I see in the instructions it says to clean and oil the filter and it says to use their brand (of course).

1. Are there other products I can use?

2. If not, where does one find the K & N products? I ordered the filter on-line.

Thanks!

[racer1735]

Best to stick with K&N's cleaning products, as you know it will be 'safe' for the filter media. You can find the cleaner and oil at most auto parts stores (AutoZone generally carries it).

[sw_freak]

Best to stick with K&N's cleaning products, as you know it will be 'safe' for the filter media. You can find the cleaner and oil at most auto parts stores (AutoZone generally carries it).


Thanks for the info. There's an Autozone about 5 miles from me. I'll stop in there.

Thanks again!

[kingprawnokay]

I love my K&N and noticed an immediate positive difference once it was installed. The engine response is noticeably improved (4-6k rpm) and I can actually hear slight intake noise (whistle) with reving! Almost sounds like a sport bike. Added 2bros pipes, and now the ST sounds like a motorcycle instead of an electric sewing machine. The bike breathes better and runs smoother than ever. I don't care if it costs the engine a couple of miles in the long run. What's a couple a miles down the road when I'm enjoying the ride so much right now?
:03biker:

[Burger]

At last... For 20 years I've been telling friends that the only things a K&N filter does for you is make more intake noise and allow bigger particles through to the engine - hence faster wear and damage. A magazine in the UK - Popular Mechanics did a test some 20 or so years back that proved this. Still, they sell like hot cakes as people search for those extra 1 or 2 HP. So I gave up commenting :)

With all my vehicles, I've always believed that the manufacturer struck the right balance between power and reliability. Let's face it, they want power figures as much as you do when they know it's going to be compared to others, but they won't do this at the expense of reliability. If K&N filters were that good, they'd be fitting them. IMHO.

I know the argument that it's cost related, K&N, buy it once, oil it for ever more, but even that doesn't stack up because it doesn't take into account how much faster you're wearing out your pride and joy.

Regards,

[tdeboeser]

My Superhawk ran for 36k with a k&n. Everything always checked out, no probs with that motor (man whata motor!). I would think that K&N would have been sued outta business by now. 35 years in business, something woulda hit the fan by now.

The points made by others are vaild, I'm not flaming, just saying.

EDIT: oh yeah, the filter will only help at full twist...

Tom de

[kingprawnokay]

Some very good ideas regarding the effect over time of aftermarket airfilters have been posted on this thread. However, I'm not quite sold on the claims of significantly decreased reliability and agree that the market would have squeezed out K&N if they made an unsatisfactory product. I like drama, but c'mon. A good example of losing market share due to quality issues is Dodge/Chrysler/etc. Dodge trucks have reliability issues with or without aftermarket air filters...and with a turbo, forgeddaboutit.

Fact: Any and every performance modification made to any internal combustion engine will probably increase/speed-up wear on the engine.

Fact: Manufacturers weigh performance costs against reliability and find a compromise.

We all perform an informal cost analysis when we determine the performance products to buy for our bikes. Added performance isn't for everybody. However, I find it hard to believe that anyone on this site using a K&N will experience significantly decreased engine life. As usual, I might be wrong. My motor might blow tomorrow.



:03biker:

[ligito]

And magnets for the fuel lines are still sold to believers, for economy enhancement.

See a similarity?

[kingprawnokay]

And magnets for the fuel lines are still sold to believers, for economy enhancement.

See a similarity?

Ohhhhhhkaaaaayyy...:confused: Man, you're really out their. Race spec vehicles use performance air filters, but I've never heard of them using magnets.

[ligito]

They used to attach cow magnets to the fuel lines.
They did this on race cars, too.
Some thought it made them go faster--others were skeptics.

Whether a K&N is worth the wear, is up to the individual.
I had one on a Honda 750K.

I won't use one now, because of the wear and because I don't care about a
slight power improvement.

Forums are great.

[kingprawnokay]

Okay, maybe you're not so out there. I had no idea they used magnets on race vehicles. :o: Learn something every day.

I like my swiss cheese air filter. ;)

[BigBadblue]

Here is an offical documented test using a Duramax diesel filters for a test bed. I have not studied it completely but the dust test is a real gem. A Delco paper filter allowed 0.4 grams of course dust through and the K&N allowed 7 grams through and the K&N clogged one of the the quickest. There is a lot of data here to absorb, tell me what you think.

http://home.usadatanet.net/~jbplock/ISO5011/SPICER.htm

[Jeff F]

Fact: Any and every performance modification made to any internal combustion engine will probably increase/speed-up wear on the engine.

Fact: Manufacturers weigh performance costs against reliability and find a compromise.

We all perform an informal cost analysis when we determine the performance products to buy for our bikes. Added performance isn't for everybody. However, I find it hard to believe that anyone on this site using a K&N will experience significantly decreased engine life. As usual, I might be wrong. My motor might blow tomorrow.

:03biker:

K&N - I've thought about it but haven't done it & probably won't, but I agree with you, all things considered a K&N can't be overly detrimental to engine life, if at all.

Your "FACTS" caught my attention tho - I was inspired to comment

- there are a lot of products and a whole service industry dedicated to enhancing performance and increasing engine life. These 2 things don't have to be mutually exclusive and often aren't, as some might say is the case with the K&N - in fact having them occur concurrently is the whole point. One without the other is failure.

Example1: Aluminum flywheels greatly increase horsepower and engine life. Lighter than factory steel flywheels and produce less stress on the crankshaft and bearings. This is a common enough "farkle" in hi perf street cars.

Example2: Engine blueprinting has become standard procedure in many performance engine shops. Blueprinting is an absolute necessity to obtain maximum power and to insure the longest possible engine life and reliability.

Example3: There are numerous engine additives that claim both better performance and longer life - ... grain of salt - I know, but they've been doing it for years and survived legal &/or governmental challenges to their claims.

FWIW

Cheers,

[Kennedy]

Honda filters for me when it is time to change mine. I figure the engineers that designed the bike must know some thing and in the HP race from the manufacturers they would all be using the KN as original equipment if it was that easy to boast an extra few HP.

[kingprawnokay]

I knew I'd get in trouble for the "fact" BS. :D

The article posted above from Testand Corporation is very, very well written. Although the specific ST filter is not tested, I felt the report followed a well devised method and provided insight regarding "high flow" filters. I need to review and revise all of my beliefs regarding air filters. I will keep an eye on my airbox! Thank you for finding the article. :bow1:

[BigBadblue]

Everyone is entitled to their own opinion, Paul has had good luck with gauze/oiled filters. I myself rather not wait to have bad luck and seek out all the information possible to avoid it. I posted the link to provide people with more information to make a more informed decision, not to cause friction. I think there is very little to find fault with as far as unbiased test data. To me, less dirt among the moving parts in my engine has got to be a good thing.
I crunch data for a living and carry it into my home life, just my nature. Just about anything I buy, I research it to death, cameras, tires, even garage door openers, it drives my wife nuts but I can't help myself. And I know all the information available on the net just adds fuel to the research fire. Can't be too bad though, I have a ST.
SFSH

[nm6r]

Once again, I call BS on the K&N allowing more dirt because it allows more air flow. Just the fact the OEM filter has that perforated screen will limit air flow. The same would be true if you put a screen in front of your radiator. You would restrict air flow through your radiator.

Will a K&N air filter cause my vehicle's mass air sensor to fail? (http://www.knfilters.com/faq.htm#6)

What is the micron rating and filtering efficiency of the K&N filter? (http://www.knfilters.com/faq.htm#10)

Ray
http://www.frontiernet.net/~st1300rider/smile04Bikerwheelie.gif

[BigBadblue]

Huh? Did you look at the test?

http://home.usadatanet.net/~jbplock/ISO5011/SPICER.htm

[racer1735]

K&N's do let in more dirt matter than some other filters, but flow more air, too. They are the standard filter on many 'hi-tech' race engines, including Honda's IndyCar Series 3 liter V8. I know that the engines are rebuilt every 800 miles, but if you stay on top of your maintenance, change the oil every 3,000 miles, service the filter as required, you won't have a problem.