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Here we go again.

I don't think you are going to see any gains with the aftermarket filter unless your stock one is obstructed with 7 years of crap. The short answer is you only need more air in if you plan on pumping more air out("change exhaust)

Good luck.
 

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I use K&N filters for my bike and there is a hp gain that you not even notice with your "seat of the pants" dyno. The reason- flows more air. Oiled filters my be messy but they last forever if you follow the care instructions. As for your bike- It's a 99 ZX 6r- it's worth around $3500. Don't spend money on hot rodding it. Just ride and be happy. If you want some suspension work done to tighten it up fine, but spending money on motor hop-ups is a waste of money on that year bike. You'll never see a return and there is NO WAY you can make that bike compete head to head with todays 600 supersort bikes.
 

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Re: K&N vs. BMC vs. JC Penney

I use socks. Argyle works bestus.
 

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You have to do the total package to get the full benefit. K&N-jets-exhaust. You have to look at the engine as an air pump. A K&N or any other free flowing filter lets more air in, re-jetting allows you to add more fuel to match the increased air flow and a properly tuned exhaust allows you to vent more exhaust out. Just doing exhaust or filter won't make any real difference because you'll still have an obstruction in either the intake side or the exhaust side. if you don't re-jet then you'll be starving an already lean engine of even more fuel.



Also, don't believe mscuddy about the argyl's he still wears black socks with his shorts and sandle's......
 

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For all the money you'll be spending you'll sound cooler but will still get smoked. If it were me I'd get some lockable/ removable luggage, rain gear etc. That's about the same price as a can and filter, isn't it?
 

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The Toad
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There's probably never been a time in history when rejetting, putting in a K&N and putting on a accessory exhaust will result in less gain than it does today. So ,if you want to spend upwards of a grand to get maybe a couple of horsepower, be my guest. Big bore kits will get you more gain than anything else.



On the downside if you use a K&N and don't rejet you may very well lose horespower. Bikes run pretty lean as it is. And any backfiring on compression braking reveals the bike's owner as an idiot.



The true advantage of the K&N is that you can wash it and reuse it. At cost of airfilter at the dealer every change you'll pay for that K&N pretty fast.
 

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..and a Panama hat with a purple hatband...
 

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Re: K&N vs. BMC vs. OEM vs. Common Sense

..yeah, if you don't oil 'em or let 'em dry out...

Guess that's why they use K&Ns in Baja...dirt adds octane and works kinda like JC Whitney's "Piston Seal".
 

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I have a K&N filter on my Harley. I have noticed that when looking closely at the filter that there are some pin holes in it where there is no filter media. I replaced one because of this but the new one has them too. No, I did not blast the filter with compressed air. I just don't worry about these holes but they are there just the same. Yes, I have oiled the filter and those holes are still visible but they are small, pin hole size. Pizz Poor quality if you ask me.
 

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For what it is worth, a buddy of mine who races endurance did a little test on two of his bikes. One a ZX6, the other a GSXR750. He tested stock air filter, K & N, and BMC. He dyno tested them, and found that on the GSXR, the stock air filter worked the best. Obviously no increase in hp, but not the loss he found in the aftermarket filters. On the ZX6, he found the BMC worked best, however the gain was minimal. It pretty much comes down to the type of material used in the stock air filter. He also found the power delivery of the BMC and K & N was not a smooth as stock.



I run BMC in my CBR1000, because I found the manufacturing process of the filters is superior to that of the K & N. Just a better all around filter. Whether it is better than stock, I doubt it. Just something to spend money on I guess. Exhaust, air filter, power commander. It has been drilled into my head long enough that I bought into the deal. The only thing that made a noticable difference was the exhaust (a slip on by the way). Well, that's my $00.02.
 

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It's very important for each motorcycle manufacturer to be able to claim that their bike makes the most HP.

If they could safely produce more HP by just changing an air filter, don't you think that they would do it themselves?
 

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Ivan of Ivan's Performance says stock filters work fine on his jet kits. My '02 6R is rejetted, repiped and has a Factory ignition advancer and I gained about 2.5 hp. Not a big gain like I was hoping but what the jet kit did was fill in the hole in the dyno chart between 5 and 7K. The best mod for the money imo is a 520 conversion. I dropped one tooth in the front and went up one in the back and it really gave the bike some "pop."
 

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K&N's do NOT work....They let all kinds of crap in the motor that a foam (Uni type) or OEM paper type filter will stop. They do have a great marketing department however and that is why they are popular. Also, as a BMW tech, we have seen cases where the K&N filter oil has ruined oxygen sensors. Buyer beware and stick with OEM for maximum filtration.
 

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I have K&N air filters on all my bikes. One is a '75 CB750F with 102,000 miles on it. The K&N has been in there for 90,000 of those miles. I lived in a house at the end of a mile long gravel road for almost six years in Alaska, and presently live at the end of a 1/4 mile gravel road here in Idaho for the last 5 1/2 years. The road in Soldotna, Alaska had the extra ingredient of volcanic ash from the Redoubt volcano - very abrasive stuff. The engine has never been overhauled and I do not have to add oil between changes every 3000 miles. I believe that if K&N filters let dirt through like a lot of people claim, top end wear in that engine would have resulted in oil consumption. Read K&N's website for a discussion of those pinholes.
 

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Yeah um don't listen to that guy that mutterred something about your bike not being able to keep up with current 600's..... I know a guy with that exact bike, which I believe only had the filter, a exhaust, and jet kit, and no engine work and it was dynoing at around 109 hp at the rear wheel which is pretty comparable to bikes today.



Also keep in mind that I had a 2000 600f4 that had the same mods (filter, exhaust, and jet kit) which dyno'd a maximum of 98 rwhp and I kept up, if not beat him, all the time. That's the difference a hundred pounds of body weight will make.



You definitely need to do an exhaust, and if you do so you definitely need a aftermarket filter at the minimum. They provide the extra air flow you need for the extra fuel you can add w/ your jet kit, and to balance the more air you can kick out with your aftermarket exhaust.



I have not seen any 'driveability' issues in low to midrange power band (or anywhere) on all 4 of the bikes I have done these mods to and I have done the mods one at a time. (600f2, 600f4, ex250, and a 900rr).



My experience overall is that the filter normally doesn't increase hp by much if at all, it does normally smooth out the powerband though which makes the bike more fun to ride. This smoother powerband is also probably the reason why most people say they feel a 'seat of the pants' increase in power. It does also allow you the airflow to play w/ jetting and exhaust. I'm a K&N guy, but have no experience w/ other brands and assume they would be just as good.



The key to these bikes in general is solid carb work. It took me a long time to iron out the kinks and for a beginner your best bet is to take it to a trusted mechanic and have him tune it on a dyno while tweaking your filter, carb, and exhaust setup. I would argue that any driveability issues are more then likely from a poorly tuned jet kit then any issues with the filter itself.



Do those three mods and you ought to be seeing 100-110 hp which brings your bike to simply a matter of skill and who has it. You'll prob. get toasted by anything other then a 600, but you ought to be able to keep up w/ new generation 600's at least in the straight lines we have here in Florida. If you are not happy w/ that, I recommend selling your $3500 kawi, going Honda like me with a nice used fireblade, and start enjoying toasting modern literbikes *grin*.



Rob
 
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