dna vs k&n vs bmc filters

**orangeback** · 15th March 2006, 21:49

WHATS THE PREFERANCE as ive got a K&N in the bus and run a BMC in the blade id hade b4, and now there is DNA. who's hade one and do they say good things about them????, as im hearing K&N seams to be lossing it in the market place , by not realy moving with the modern materails as the BMC and DNA ????
http://www.dnafilters.com/
http://www.bmcairfilters.com/

The stock air filter flows pretty good, but then again you'll find the guy's out there who swear up and down by their personal preference (K&N or BMC or DNA). Exhaust systems are where your first upgrades usually come along. Bolt-on or slip-on can's if you're looking for just sound, full system's for performance. The gisxr 600's and 750's don't have set valve'shttp://www.bmcairfilters.com/ . Get a Power Commander and have it custom mapped on a dyno after you do anything like air filter or exhaust system.

quote ;

get yourself a fender eliminator for the back to get that snow plow off of there
remove those fugly warning stickers, etc...

**Motu** · 15th March 2006, 21:53

So what's a BMC apart from a defunct British vehicle manufacturer? DNA I know all about,I've used it to build 4 kids.

More detailed descriptions and links to your products for those of us who don't know.

I know about K & N - they make lots of horespower and kill engines,their blurb is all about HP increases and very little about air filtration.

**Toast** · 15th March 2006, 22:03

I asked at Mt Eden M/C for a K&N, and was promptly steered away from it to a DNA. Reason being that, as Motu said, they just let too much shit through. The DNA did seem to make a small but noticeable difference on the first ride, bit more power, seemed to crispen up the throttle response and made a cooler sound...maybe psychological, but at the least, it never gave me any problems with reliability...bike ran like a dream for the next 18,000kms before I sold it on.

**Cajun** · 16th March 2006, 06:41

I have found with suzukis air filters make sweet all difference, unless you are racing, its best to keep with the stock all in all.

I am running a bmc in my k4 600

**Fishy** · 16th March 2006, 06:53

My stock filters are almost buggered @ 12,000k's so I just purchased 2 K&N's (my bike has 2 cylinder shaped filters) from the states... $150NZ landed.

**White trash** · 16th March 2006, 08:22

Interesting what Motu said, I've heard the same from other mechanics. I thought if you kept 'em well oiled you'd be sweet?

On the DNA front, we fired one in a GSX1200Y and chucked the bike on the dyno, it was so lean (from increased air flow) the bike wouldn't idle. If it lets that musch air through, what else is gettin through?

**Fishy** · 16th March 2006, 08:31

So what are the symptoms I should look for to indicate that my bike may run lean after fitting the K&N's?

**jimbo600** · 16th March 2006, 08:53

Originally Posted by White trash

Interesting what Motu said, I've heard the same from other mechanics. I thought if you kept 'em well oiled you'd be sweet?

On the DNA front, we fired one in a GSX1200Y and chucked the bike on the dyno, it was so lean (from increased air flow) the bike wouldn't idle. If it lets that musch air through, what else is gettin through?

Oi fucker you sold me a DNA. Now I'm no mechanic but when I pulled it to check how clean it was I found a possum in the colector.

**Lou Girardin** · 16th March 2006, 11:16

Originally Posted by Fishslayer

My stock filters are almost buggered @ 12,000k's so I just purchased 2 K&N's (my bike has 2 cylinder shaped filters) from the states... $150NZ landed.

That's around what Finn paid, and he had the pleasure of dealing with the best bike shop in NZ.

**DMNTD:Me** · 16th March 2006, 11:54

I'd like to upgrade my air filter to one of the above mentioned and was wondering would I HAVE to have my bike re-mapped?

**The Stranger:Me** · 16th March 2006, 12:13

Originally Posted by Motu

I know about K & N - they make lots of horespower and kill engines,their blurb is all about HP increases and very little about air filtration.

After many comments similar to this when I had occasion to remove the tank after 18,000km with the K&N fitted in the Blackbird I was dreading to see the clean side of the air box.

I opened the air box, took a deep breath, removed the filter and hey shit where is all the crud?
Well it must have accumulated in the throttle bodies, no not there.
Well of course it is, it is just microscopic and I can't see it. I know I'll wipe it out with a clean white rag. Hmm still none, rag is very clean.

This is further to my experience with my son's Nissan Primera which had a completely choked (like all fins filled) K&N in it when he got it and no (visible) dirt on the clean side of the airbox.

So I don't know, how bad can these things be? More power, better fuel economy and no detectable dirt after 18,000km, despite there being at times 260kmh (on closed roads only of course) ram air trying to force anything and everything possible through the filter.
But I do know the first thing I bought for the X11 was a K&N.

Oh and check here for some information on filtration.

**Cajun** · 16th March 2006, 14:13

Originally Posted by TL Rider

I'd like to upgrade my air filter to one of the above mentioned and was wondering would I HAVE to have my bike re-mapped?

It would be best if you are running a pipe and air filter. but best bet is decided on all mods you are wanting to do, and them them all at once, then maped same time.

I noticed when i put the filter in my bike i lost a bit of the ram air growl it had before

**Motu** · 16th March 2006, 14:39

http://theoildrop.server101.com/ubb/...;f=15;t=000504

The oil freaks are the ones to talk to about K&N,even then there are pros and cons.But generaly oil analysis shows higher silicon levels with a K&N.Do a search on that site about K&N,lots and lots of discusion,and generaly they say no.

Heavy trucks and earthmoving equipment are the ones serious about actual air filtration over performance - you won't see K&N there.

Do an oil analysis with and without if you want to prove it - but I take their word for it.

**imdying** · 16th March 2006, 14:45

Interestingly enough, wasn't it K&N that developer the filters to be used on the Apache gunships in the Desert Storm conflict?

/edit: Some info here: http://www.bmwe34.net/E34main/Upgrade/Air_filter.htm Even a response from k&n themselves.