The truth about aftermarket air filters

[mrlmd]

Found this on another site, thought you guys might like to read it, put it here for maximum exposure. Don't believe all the ads and hype and anectdotal comments you read/hear.

http://www.rc51.org/airfilt.htm

[mrlmd]

Found this on another site, thought you guys might like to read it, put it here for maximum exposure. Don't believe all the ads and hype and anecdotal comments you read/hear.

http://www.rc51.org/airfilt.htm


Sorry it came out twice - I can't seem to delete this one.

[kkim]

lol... and you feel so strongly about this that you had to post it twice?

[CC Cowboy]

Deja Vu

[WindMeUp]

Originally Posted by CC Cowboy

Deja Vu

Oh, I take it we have been here before then? Better breathing comes at a price.

[Snake]

So good I had to read it both times.

[Flashmonkey]

Thanks for the link, Marc. I agree with that blurb for the most part. While cars have very restrictive systems sometimes, the intake system on a bike is usually much simpler, and there's usually very little room to improve upon. Obviously this will depend on the actual bike.

I actually only bought a K&N for my bike because spare parts for it are harder to come by with each passing year. Probably should've looked into that before buying it...FML.

[mrlmd]

Originally Posted by kkim

lol... and you feel so strongly about this that you had to post it twice?

You can never have too much of a good thing.
Or does that belong in the quotes thread? LOL.

I couldn't find anyway to delete that second post, and I only hit the button to post it again because the site was so slow at the time, I didn't know if the first one went through 'till it was too late.

[highpsiguy]

Hmmm I have been thinking about buying a K and N for bike. I have one for my truck and get an extra 2 mpg on average.

[Racer x]

As a mechanic . I always laugh when a car comes in with a K&N filter that is packed with dirt. Life time to some means never touching again.

[Flashmonkey]

Originally Posted by Racer x

As a mechanic . I always laugh when a car comes in with a K&N filter that is packed with dirt. Life time to some means never touching again.

That's what it means to me! woooooooooooooot!

[Sailariel]

Originally Posted by mrlmd

Found this on another site, thought you guys might like to read it, put it here for maximum exposure. Don't believe all the ads and hype and anectdotal comments you read/hear.

http://www.rc51.org/airfilt.htm

Marc, How come I am not surprised? Now this is my opinion only. I have no problem deferring judgement to the Kawasaki Engineers. When you look at the OVERALL bike, the fact that these folks did their homework does stand out. Sure there are some Mickey Mouse shortcuts that were taken--e.g. suspension and seat design--and there are others. Let's look at suspension. How many of us, in all honesty, have the ability to benifit from a more sophisticated change in that area, and still meet the price point Kawasaki's research department has carefully researched? I have been riding 50 years off and on and have never owned a bike that is more nimble, as flickable, etc. All the things our insurance companies find wrong with sport bikes are considered virtues by sport bike riders---superior acelleration, superior handling, and superior stopping power. (I heard this from an insurance company person: The traits mentioned above CAUSE sport bike riders to ride more agressively.) That's pure BS. There is nothing wrong with a stock bike. Sure we can improve the bike with Corbin seats, ZG windshields, aftermarket tyres, perhaps a 15T sprocket, and so on--which is fine--I did it, but I did not change anything the engineers so carefully researched. There is nothing wrong with experimenting. It is a challenge and it is fun. I tend to leave things alone.

[bob706]

As far as the 250 goes at least for me, stock air filter FTW.

[mrlmd]

I think most "modders" somehow think they are smarter than the engineers and designers who build these things, that they know more, that they can improve on something to make more horsepower or whatever they are looking for. For the most part they are wrong. Like high octane gas is better, more power, runs better, has more and better additives, etc, and they are way wrong about that.
If you replace something like an air filter or mod the airbox to improve "flow" (which is adequate already), then you have to rejet and also redo the exhaust, to get any benefit and have the bike not run like crap. You must mod all three to keep it running right. You may spend hundreds of dollars to gain, what, 1 hp, maybe 2? Now granted, most all bikes sold here come lean from the factory for emissions controls and possibly could be tweaked a little, but the overall benefit in terms of dyno measured horsepower is minimal if anything, and fuel economy suffers when these mods are done. I think the engineers did a pretty good job, I think they know what they are doing, and their warranty attests to that and the bikes perform pretty well as is out of the box, until messed with, and then people have all kinds of problems trying to straighten it out and blame it on Kawasaki or whoever made the thing. I am quite satisfied with the performance and reliability of my bikes as is and I think messing with them does just that - messes them up. The retail value of a modded bike is also lower than stock. I am perfectly OK with customizing the appearance or adding things like headlight/brakelight modulators and louder air horns for increased safety, or altering the body work to their own taste, but mechanically I will leave them alone as they work just fine.
There are innumerable threads on here and on other forums of individuals who did extensive mods costing hundreds if not thousands of dollars in which the net effect measured objectively was very little. All they accomplished was poorer gas mileage and a great sacrifice of reliability and longevity. But it may have made then feel good so it may have been worth it to them.
You want more power -- then get a bigger bike. Just my opinion. I'm sure I'll start some kind of argument on here because I'm sure there are many opinions different than mine.

[kkim]

you're entitled to your opinion, even though I don't agree with it.

[ztrack157]

My air filters are free so JFC FTW. Otherwise I would run stock. For those running the KN0990 me and a racer of mine found out that pod filters actually loose hp overall. The gerry rigged intake we came made proved to be best combo. We didn't use the stock runners from the airbox but there is a reason why they are there.

[Nemesis]

Truth is, you may see an increase on paper but the gains (if any) are so minimal it's hardly noticeable.

With that said, it's just one piece of the puzzle. Buy all the other performance parts, put them together, fine tune it, and you'll see a huge gain.

By itself, it's not worth it.

[mrlmd]

Originally Posted by kkim

you're entitled to your opinion, even though I don't agree with it.

I have no problem with your point of view either. That's what make us all individuals, what makes the world go 'round. Maybe one day I'll play with my carb too, but right now my bike runs so well I have no reason to think of doing that.

I'm a very pragmatic guy and would like to see some unbiased scientific objective evidence and proof that something works as stated or advertised, no matter what it is, other than hearsay, opinion, hype, advertising, or anecdote. If you want me to switch from doing it my way to yours, then prove to me yours is better. If there's so many more ways to do something, then most of the time it makes little difference which way you do it, that's just personal preference, but the end result is often the same. If one way was proven to be better, then everyone would do it that way and that would be the norm. I find that a lot of what is sold or is done is based on advertising or hype with very little gain except financially for the company promoting it at the expense of the cult or following that falls for it and buys the product. This is not always, not a blanket statement, but is often the case today. Like high octane gas is "better", nitrogen in tires is "better", this air filter or exhaust is "better", etc, up to my God is "better" than yours (from another discussion on here). I have no problem with any mods if anyone can really prove they do something other than make the modder feel happy (which is OK) or that he thinks he accomplished something and his bike is "better". Obviously, sometimes something needs to be fixed, but modding a carb to get the bike to run properly oftentimes is done because it is treating a symptom of poor maintenance, abuse, or another bad mod done to correct a problem which didn't exist in the first place. Can you post another poll about "What is your gas mileage for your stock bike vs. the mileage for your carb/exhaust modded bike? How many bikes on here were tested before and after to see if the 0-60 times actually improved, or the dyno tests demonstrate any real difference in performance? Obviously most everyone on here doesn't do that or could afford it, but all say their bike is "better" but no one can prove it. I'm not down on anyone who wants to play and try and improve their bike's performance, I am just not convinced that any of this really does anything significant.

[kkim]

Marc,

If you're happy with the way your bike runs and don't want to experiment, I can live with that.

I know what I want out of my bike and try to systematically address what I feel are shortcomings that can be remedied with parts available and still maintain a bike that hopefully is better than what I started with. As long as I'm happy, I really don't care what others think/feel about what I do with my plaything.

[WindMeUp]

In the quest for HP your dollar is better spent on more CC's and not mods on a smaller engine, unless you are competing in a CC class in some sort of sanctioned racing, then yes..throwing money at a certain size engine is a different story.

EDIT: Modding is fun, but you will finally get to point to where you are pissing in the wind as far as your dollar spent and what you will get in return.

[tapdiggy]

Aftermarket air filters are a nice alternative if they are replacing a foam OE filter. When the filter needs to be cleaned and reoiled, I like working with a K&N kit (spray bottle of cleaner and aerosol can of oil) than an open basin of cleaner and motor oil as per the owner's manual.

[ztrack157]

I have three dynos at my disposal. I have dyno graphs showing gains from a drop in air filter, no filter, pod filter, stock intake runners with unis on the end, and the top secret combo which won't be mentioned. And High Octane is better for my bike and others with similar setups but it is not for those with a completely stock bike.

Your anti mod and I'm fine with that.

Whoever posts up immediately after me will receive a FREEEEE drop in air filter that will come in with my next Shipment.

[Cuongism]

I win?

[ztrack157]

Yes sir you do. PM me

[kkim]

Originally Posted by ztrack157

I have three dynos at my disposal. I have dyno graphs showing gains from a drop in air filter, no filter, pod filter, stock intake runners with unis on the end, and the top secret combo which won't be mentioned. And High Octane is better for my bike and others with similar setups but it is not for those with a completely stock bike.

Your anti mod and I'm fine with that.

Whoever posts up immediately after me will receive a FREEEEE drop in air filter that will come in with my next Shipment.

bah... just post up the dyno graphs

[ztrack157]

let me get the hard copy from Sportisi. I'll call dean in the morning and have him send me his stuff.

[tapdiggy]

Maybe it is sleep deprivation, but an RC51 would be a neato ride even with the least useful air filter setup those guys came up with.

[Cuongism]

Wow Matt, that's very kind of you. I've actually installed pod filters on my bike though. Maybe you can run a contest for another lucky member here? (or PM me the top secret combo )

[00NissanNinja]

mrlmd you are right In that there is a crap load that engineers go through when designing a bike(fluid mechanics, thermodynamics, knowledge of materials and their corresponding properties, and so forth). Just know that shortcomings will be made when trying to keep a budget on designing and producing a machine. There is also a defined market that the engineers are supposed to design toward. Thus there are reasons why some people mod the bike and some don't. They are made so that they will appease the majority of buyers and you will find a lot of the time you will have something the way you like it.

[Flashmonkey]

Originally Posted by tapdiggy

Maybe it is sleep deprivation, but an RC51 would be a neato ride even with the least useful air filter setup those guys came up with.

Frig yeah! I love that thing....

But in the grand scheme of things when mods are planned out properly and done well they can be quite effective. Going from a drop in stock filter to a drop in "performance" filter is pretty ludicrous though haha. Going to a pod filter setup and ditching the air box altogether, however, well that's something else entirely. Plus it looks cool.

[ztrack157]

secret combo pm'd

[mrlmd]

Are you really getting in any more air than the stock filter provides, any more that the engine can use? If so, then it's running even more lean than stock, so you have to do carb mods to fix it or even make it run well so the mods can function properly. You need to do both, not just change the airbox or filter. And then maybe the exhaust - it's a combo of all three that works the best. That's one point I was also trying to make.
And I know that designing all these bikes is a compromise - between cost, emissions, performance, fuel economy, reliability, longevity, etc, and are not set up perfectly for out and out optimal performance in any of these categories, but like I said, is a compromise between all of them. So you can mod it out anyway you want, to change it, and you will be changing some of the other parameters as well, some for the good, some will be made the worse in the process - it's all a balance.
I put that article up there because I think people should get educated and get a little more information about what they are doing or attempting to do, instead of just following the herd.

And I need a new filter, I started this this, I need to be converted. I need to mod, I need a filter more than anyone on here. Ha.

[00NissanNinja]

Originally Posted by mrlmd

I put that article up there because I think people should get educated and get a little more information about what they are doing or attempting to do, instead of just following the herd.

Good point.

[egutierrez90]

i can use a free drop in filter =D

[spooph]

thanks for the article! Even more so because you posted mainly for education! Knowledge is the best way to fight reverse evolution. I've been on the fence about a K&N for a while now, and I think I'll be wasting my money.

In fact, what I got out of this article is that stock air filters breath brilliantly, and that money is best spent elsewhere - exhaust for instance. That's where most of the restriction happens. I'm gonna play around with that this winter....

[dubojr1]

My 250R is down for now getting the rear wheel mod done. My 250 is modded to the max for performance and using it for reference, it has to be a better performer now. My wife also has a 250. The only mods to it is a jet kit and 15T front sprocket. Well due to mine being in pieces again I choose to ride her in to work this morning. I found myself multiple times wondering where my torque and HP was at. Granted her bike runs as smooth as a sewing machine but it does however lack the performance I have come to expect from my modded 250. I don't have any dyno's to prove torque and HP gains but they ARE there.

I totally agree that if your going to mod one thing, be prepared to change others to get the best each components has to offer. Also understand that there MAY be some loss of that "sewing machine" sound and reliability but I believe it is minimal.

[mrlmd]

Don't forget the difference in performance with her 15T sprocket. That alone will make it a lot different than yours with all the "mods" you did. You are not comparing comparable bikes.
And it's not so much that if you mod one thing you have to be prepared to change others to get the best each component has to offer, it's that if you don't, the bike will run like crap or not at all. You can't lean out any more the air/fuel mixture with a less restrictive filter letting in more air without then rejetting the carb to allow more fuel flow. And then you need to have a less restrictive exhaust. The three of those things work together, not one at a time and expecting to accomplish anything except an unbalanced poorly running bike.

[dubojr1]

I was pretty sure I mentioned that mine had all the performance mods. I can provide a list if needed but I'm pretty sure I ran our of performance mods. In short, if you can think of it, I prolly have it. Btw...mine also has the 15T sprocket.

[dubojr1]

Dyno example... Enough said

http://www.ninjette.org/forums/showp...18&postcount=3

[Rayme]

This article could be written about complete exhaust system. Air filters and exhaust both need fuel adjustment to maximize their use. That article is very subjective. Air box design have much more effect on the way the engine breath than the filter they use, so a K&N drop in in a bike might gain HP and on another one lose HP.

And don't forget that RC51 and all other fancy 600cc have an intake/air box/fuel tuned for ram air induction..