sentipede

Which is better for everyday driving conditions?
K&N or BMC replacement air filters?
And what is required for installation...Do they have to be oiled?

Thanks....

willard

K&N is useless for any type of driving.

Sorry, more than useless, actually detrimental.

Oil wicks off the filter and coats the downstream mass airflow sensor. Lower particle filter efficiency results in earlier engine failures, 190k instead of 250k.

Rob in WA

They come pre-oiled, fairly easy install; just pop the cover off the airbox. BMC is what Porsche uses in their race cars. I don't think there's any discernable difference w/K&N though.

SPR

I would go with the BMC and yeah it is what Porsche uses. as to the auction oil wicking etc. Honestly that is because someone oiled it too much, and didn't let it dry for a day or so and put it in immediately. It could also have been from using the old K&N oil which was much thicker. They now have a new cleaning kit that is a spray that goes on much easier, more consistenlty, etc. Go with a bmc though, I hear it puts out more ponies. I have it and it is loud. swwooooosssshhhh. With the gemballa exhaust it seems to work quite well! There is also a new bmc cone filter setup that is in a canister with tubing so it's not like those crappy ones. Check it out <a href="http://www.bmcairfilter.com/VisModel.asp" target="_blank">http://www.bmcairfilter.com/VisModel.asp</a>
also look at the links after you choose your model and you will see the other one that I am talking about. I don't know where the mass air flow senser is supposed to go in the pic, though! ehhe

wwest

"didn't let it dry out for a day or so"

Water will evaporate in a day or so, oil will not. In a day or so the oil coating may increase its viscosity slightly due to more volatile components evaporating away.

The fact is that the excess oil will not evaporate but it will "wick" away with the high air intake velocities at WOT.

If I wanted to "prepare" a newly oil soaked K&N for use in my 996 I would fire up the old trusty home vacuum cleaner and use it's air velocity for a few hours to remove the excess oil coating.

But I don't consider myself stupid enough to not realize that a 60% improvement in airflow is anything but a marketing gimmick.

If OEM air filters are, say, 90% efficient (10% inefficiency), then a 60% K&N improvement in efficiency over an OEM filter would only mean an improvement to 96% overall efficiency. And that 6% improvement only applies at of near WOT.

Rob in WA

Haven't we already had this discussion?

SPR

Seriously! someone is angry, and wants to destroy air filters by flowint out the filter element!

willard

Huh....?

flowint...cannot interpulate.

SPR

blowing

willard

Blowing out...

I simply can't imagine that a simple (3HP max {20 amps}) home vacuum could damage any filter, even one with only 80% efficiency, capable of handling a 3+ liter engine's intake airflow at 6000 RPM.

Trojan Man

The guys @ By Design say to stay away from K&N. Apparently they are not constructed strong enough and can actually get damaged by the airflow / turbos. (OK maybe i sound ridiculous, but i'm just repeating what I heard).

They said to go with BMC.

Hope I was somewhat helpful.