Fwiw, here's Cosworth vs. HKS on an Evo...

http://i725.photobucket.com/albums/w...opinfilter.jpg

I take it Cosworth doesnt make a filter that would fit on my Gen 3's do they??

i haven't seen one. aFe might though...

K&N--because I'll sell you a set. :tiphat:

Oiled cotton or synthetic dry works best, with slightly better flow on the oiled cotton at the cost of some filtration (slightly better for the dry). Both should flow and filter better than paper, so no worries.

Foam filters suck. The HKS is a foam filter.

I too just sell off the old for someone else to clean and purchase new ones. Less of a hassle.

based on my UOA's, which also measure particles that indicate poor air filtration, my K&N's work well.

Have you compared silicates from K&N vs. non K&N filtered on the same vehicle?

i had the HKS drop ins for about 6 months. they seemed so flimsy and the filtration looked like something off my vacuum. :\

ive had the K&N's in for a year now. so far so good!

:icon18:

LOL

You got the UOAs posted up anywhere? I'd like to check some out on the Z.

What filters are you going with now?

This discussion is specifically for OEM replacement or is cone type inicluded? I want to replace the mushrooms that come w/ the Greddy unit with a cone type filter (dry type).

Hmm. To be fair, no I have not. But silicates were all below levels of concern, so whether or not they filter better than x or y filter is unknown, but they do work well based on the ppm criterion.

Frankly, I found the oiled medium to work better (i.e., better throttle response) in humid or wet weather relative to the dry synthetic stuff -- that could be all in my head, but I've heard a similar observation from others as well, and oil does after all repel water.

If we're talking ability to filter the crap out, i won't touch K&N with a barge pole these days.

Yes they do breathe more than most filters, however, they filter fairly poorly. When i start seeing the cotton material turning up in UOA's, then stop to think for a second what the path would be to get there, i figure i'd like *some* filtering on my engine.

I don't like wet type filters anyway, dry has a lot more benefits and consistency than oiled types.

BTW, paper is the medium used to see what passes through all these performance filters, you should be using the factory/paper medium filters as a benchmark for filtration ability.


My next filter will likely be an Apexi drop in filter if not the factory fit.

Cotton was showing up in UOA's??? :icon14:

Yup :(

Re-used or fresh, never used?

One of the reasons I would just as soon switch them out rather than re-oil (provided I have the $$) is that it's all too easy to cause minor shredding in the cotton when you wash it.

And not just cotton -- I had a dryflow (i.e., synthetic, dry media) AEM filter almost completely fvcking disintegrate on me -- just from washing :icon14:

If fresh, that's a new one to me -- never heard of such a thing. If re-used, I'm not completely shocked...

I don't recall tbh, but the very nature of their makeup means they're going to fail at some random unknown point, that kind of service life is silly in some areas.

Yeesh... well, food for thought. Thanks for letting us know :tiphat:

Cosworth

What about a k&n with an outerwears cover??

A what now?

Not applicable for 370Z application IMO.