LFA951

I have an Autothority MAF 4" with an LR pipe and I've seen shorter cone filters with different shapes and even opening in the middle of the filter for better air entry and some that are like sponges, rounded, not cone shaped, but shaped like small pillows. I currently have an old K&N long cone filter, it's about 9" long and I am thinking of changing it, any suggestions, if it's even worth it?

LFA951

Come on, anyone?

George D

The foam filters mess with the MAF metering. Most of us use the K & N TYPE filters. The shape of your filter shouldn't matter. Whatever fits best and has a good seal is more important. Changing your K & N filter to another shape will be just cosmetic only.

LFA951

So you don't think that an opening in the middle will increase air flow or performance as opposed to the current K&N filter I have that is closed?

Ski

No I don't, just keep it clean.

reno808

With K&N you have to keep on cleaning the meter because of the oil from the filter thats leaves behind. which cause the meter to do funny things.

George D

True, but try a foam one. Keep your filter clean and don't over oil it after cleaning.

S2cab

Do a Google search for AEM Dry Flow. It's a sythetic media filter that requires no oil. No more worries about fouling the MAF sensor. You will need the OD of the MAF housing, & measure the length you have available in the space the filter goes. You might also need to measure the depth you have available in the space the filter goes. They look like K&N filters, but don't require oil. They are also cleanable.

George D

We tried these in our ATV's. Many Suzuki KQ 700 motors required rebuilding. We don't see nearly as much dust in our street/track rides, but I don't like what happened. We can't prove it's the filter, but my foam oiled filter KQ 700 motor is just fine.

TRP951

I thought they dont filter as much or they dont flow as much cant remember which one it was. I did reading on them and decided not to switch to it

LFA951

I never oil my K&N...

George D

Think about what happens when small particulates come in your intake. Paper filters are NOT as good as a properly oiled cloth or foam filter. If we could get flow from paper, that would be the choice. K&N cloth when oiled properly do let more through than a high end paper filter, but they flow better. Foam is the best, but the cells are larger than cloth, so the oil gets sucked into the intake. No big deal for a motor that sucks. The velocity is much less that a motor that gets air RAMMED down it's throat. Foam doesn't absorb the oil, it holds it withing it's large webbing. Cloth has a much smaller webbing to hold the oil, plus it absorbes the oil within the fabric which allows much less blow through.

Long theory short, cloth oiled filters for our cars are best, paper is second best, and foam requires too much maintenance. No oil filters are stated to be fine, but seeing blown motors in quads leads me to say no to them.

Street driven cars, its probably fine, but I'm not using them.



Anyway,

George D

Fine, it came oiled.

LFA951

I figure if I oil it, it will impede air flow, reducing it...

S2cab

There was a dyno done on a friends FZR600 many years ago. The used stock air filter was dynoed first. A brand new K&N straight out of the box was dynoed second. The same K&N filter washed & reoiled (sprayed) by hand was dynoed third. The K&N out of the box lost two HP to the used stock paper filter. The washed and lightly oiled K&N filter gained two HP on the used stock air filter. That's a four HP swing just by cleaning & lightly reoiling the K&N. It's almost like they dunk the filter in oil when K&N does it.