The Air Filter Debate

[Plunk]

Well I've searched all through the forums and come up with a lot of good info on air filters. Basically it looks like the order of preference is BMC race, BMC street, and then K&N in that order. How much difference can be seen between a BMC race and street? I realize more air in + more air out = more power but will the average joe notice it.

My bike is about to get an HMF dual high mount system and a PCIIIUSB. I'm not really a racer and I don't plan on going big bore, turbo, or spray. I bought a BMC street, but after further research I'm starting to second guess my selection. Any opinions from the speed junkies out there?

 

[Johnnycheese]

I have never ran an Air filter in my Busa.. or any other Ramair bike.

 

[Plunk]

Are you saying you remove them completely?

Doesn't that let nasty things inside the engine?

 

[SierraFlyer]

Long time guys, I have been hybernating since the bike is stored for winter. But this question brought me out for Spring!

You may find that the BMG race filter will give you more HP than all the other filter choices ONLY if you fatten up the mixture by remapping. The stock fuel squirt is lean to start with, especially at the low RPMs, and then you reduce the air restriction alot with these high performance filters. More air with same fuel drives the mix even more lean. Not good for power. So if you run a BMG or K&N, etc., do it right and get a module to adjust the mixture too. Otherwise you are wasting money.

If you think this sounds crazy, I fattened up my idle and off idle mixture last July and the fuel milage went UP 4 MPG.

My two cents......

Now back to sleep until the snow melts next month.

 

[Plunk]

I agree with you there. The question I'm really after is there really a noticeable difference in BMC street vs race.

 

[WarBaby]

There is V-E-R-Y strong dyno and track evidence that the stock Hayabusa air filter flows more than BMC or K&N.

 

[BusaFever]

There is V-E-R-Y strong dyno and track evidence that the stock Hayabusa air filter flows more than BMC or K&N.

Tom,

Could you post a link to that evidence. I am all ears. Never heard that one before.

-Bill

 

[WarBaby]

No, I can't.

This info came to me from a prominent tuner who conducted multiple tests resulting in the conclusion I posted. Suffice it to say that I sold my BMC Race filter because of the data. Sorry, I don't mean to be cryptic but I am obligated to say no more.  

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[vincent]

interesting, can we expect to see proof of this anytime soon?

 

[WarBaby]

Probably not from me in this case. I made a committment and will honor that agreement. It's not a secret though, nor is it the first time I've seen "premier" filters result in zero power gains, and even power loss, however small. It is totally understandable if it is perceived as a dubious claim, and admittedly, there is very little performance difference among any of them.

 

[tlronny]

The stock filter is just fine
Most aftermarket filters are pure marketing HYPE !! unless you've done serious mods to the rest of it.
The only bonus is that you can clean em but is it really worth it ?
Spend more time riding the thing and less time looking at it and thinking that there might be summit wrong wiv it !

 

[Plunk]

Spend more time riding the thing and less time looking at it and thinking that there might be summit wrong wiv it ! [/QUOTE]

Amen. Well, that being said I'll continue on my way. Half of my hobby with the bike is the tinkering. But there's nothing like the feeling of cracking the throttle on the Busa. Thanks for all of the great info guys.