K&N Air Filter can lean A/F and run engine hot?

Deadeye

Deadeye
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Hi! Received a K&N air filter for Xmas and installed it. Drove to a local shop and friendly folks advised me to go back to stock as without a power commander (yet) and stock cans - the new filter would lean out the A/F and make the bike run lean/hot... I've read similar posts but my question is "Am I damaging the engine without the ability to remap a/f mixture?" Seen/read mixed posts re losing 2 HP, gaining HP, its a better filter, worse. Slight power loss worth better filtering and decreased cost over time etc. Hate to throw away / sell a Xmas present but don't want to hurt the Busa ...
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My amateur opinion says working with other type motors, the better filters allow the motor to breathe much better. As in allowing more air into the intake with the same amount of fuel. This WILL lean out the mixture. I have seen a number of very small engines run lean enough to do damage. Someone with REAL experience will need to fill in more of the details.
 
I agree ... need some of the experts ... "the guy at the shop" said that many engines benefit from a K&N filter but not the Busa engine ... " ... Thanks for your comments though! -- have to contact you guys about a couple mods on YOUR bikes = more money!!!
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added d&d slip on's and a k/n filter and had my stock computer re mapped for both by my suzuki dealership.......runs very strong all the way thru the rpm range with no problem... no evidence of a lean condition
 
I'm a hot rodder by nature having an old school 5.0 litre mercury capri and an 02 Mustang GT makin' 290hp to the wheels, K&N's improve air flow to the engine,,,,,enough to provoke a slight lean condition but not enough to cause a dangerous lean condition.   IF that were the case noone would buy them for their performance gains at all for fear of putting their engines in danger.  

My busa still has the stock filter but I have drilled one set of baffles in the stock cans and so far no  problems.  I was looking myself to get a K&N or a BMC filter for my busa and different exhaust and I asked the same questions at my dealer.....remapping the computer is not necessary but is highly recommended to keep the bike running right  in optimum contdition and prevent any lean conditions.  

IMO, keep the K&N and use it.  If you feel you need to remap, get it done and feel better.  It may not be needed but it is cheap insurance that puts the  mind at rest.   Good luck and if you decide to sell it, PM me.
 
Yeah that's what I was thinking too ... but the guy was pretty adamant. Also mentioned a member "Brock" I think that has dyno or data from tests that supports the "too lean" and "actually loses power" angles. I don't think (hope) that it will actually hurt it. As to the "more in, therefore, more out" post ... Any threads or pics on drilling out the stock cans? Thanks for all the comments. All the best in 07. Oh, one more thing! As soon as I get out of the Xmas rush, marry off my son (6 Jan) and pay a couple bills - I'm gonna be a contributing member - what an awesome site!!!
Deadey
 
Sometimes what happens is that stock bikes are on the lean side from the factory...emissions and fuel economy concerns...so when you put a less restrictive
filter on your bike it ends up too lean under certain conditions.
 
Kelley,

I'm a mechanic by trade but I'll try to quickly learn to post pics unless someone can talk me through it.  I bought a 1 1/8" hole saw w/ a 12" extension to drill out the first set of baffles in the stock can.  I Believe the exhaust gases make at least 3 passes inside the can before it exits the muffler.  

You'll need a dremel tool w/ the small fine cutting discs to gently cut the welds holding the allen wrench headed polished screws that hold the exhaust tips on..... so you wont damage or scuff the tips in the process.  When you look inside the muffler inlet, you'll see an offset pipe and then beside that a slightly flat spot in the shape of a crescent.....the crescent is what you want to remove.  By doing this, you eliminate one of those chambers or baffles the exhaust gases pass through.  

The result is a little bit more crisper throttle response and quite a bit more aggressive sound.  Albeit, it's not the 2 brothers or yosh sound we all love so much but it's a significant step up from the stock sound.   My bike runs great, has a little bit less backpressure and sounds really nice.  I've got a few days off this week and I'll study up on posting pics and see what I can do for you.  I hope this helps and good luck if you pursue this avenue.

Henry
 
I put a K&N on my gsxr6 and thats it, rode for around 30K with no problems. Of course I do all my riding around 6000ft so might have more to do with it to.

I woulod say if you just put the K&N on it may produce a lean condition, just keep an eye on the temps if they are high try running 91 or higher octane to cool her down a bit, if that dont help then get it re-mapped or put the stock filter back in.
 
Henry and Warwgn ... thanks - good thoughts - I will wait for the pics ... I run 93 Octane and synthetic AMSOIL so I don't think it will be a problem over all - probably does lose power and run hotter though (I have no way of measuring). As to pics ... I think you can just load them by selecting the browse option at the bottom of the post / reply window where the icons are ... I'll give it a try with this email ... not sure how you do multiple pics. I think I do want to mod the stock cans ... that will start a whole new thread!! lol. Best to you both in 07. Hopefully one of the dyno smart folks will roll in on this discussion and let us all know what really happens in an unmapped with K&N - standard map condition. So! Let me try and load two pics ... one after another. For those that know - please excuse us newbies!!! jeez.

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I have a K&N on my 06le, and had one on my 02. I ride 20,00 miles a year in temps from the low 40's to the 120's; I use 87 octane; I do not have a power commander; and I have never had any heat related problems.
 
I'm running a K&N on my Busa for the last 20K miles without a problem. I have drilled cans, but the only different that makes on the Busa is the sound. It has no effect on performance since the stock headers are so restrictive. The K&N is actually more restricive than the stock Busa filter and will steal a few HP from it over stock. I dynoed 150 HP, 93 Ft Lbs in September with that setup. But on the plus side, the K&N is less expensive in the long run if you follow the maintenance schedules.

Anyway, don't let the friendly folks at the local shop touch your bike. Either they don't have a clue what they are talking about with regards to the Busa, or they are trying to scare you into buying expensive addons you don't need.
 
(Deadeye @ Jan. 02 2007,10:43) Yeah that's what I was thinking too ... but the guy was pretty adamant. Also mentioned a member "Brock" I think that has dyno or data from tests that supports the "too lean" and "actually loses power" angles. I don't think (hope) that it will actually hurt it. As to the "more in, therefore, more out" post ... Any threads or pics on drilling out the stock cans? Thanks for all the comments. All the best in 07. Oh, one more thing! As soon as I get out of the Xmas rush, marry off my son (6 Jan) and pay a couple bills - I'm gonna be a contributing member - what an awesome site!!!
Deadey
Search for drill cans. At least 3 of us have posted step by step "how to" with pictures.
 
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