Foam vs. Cotton
 

Hey!
Here's a question for the ya'll.

What is the better/best air filter material?
I've looked this up on the internet, and the general consensus is that while K&N (cotton-gauze) outflows foam, it filters less dirt particles than it. Paper filters flow and filter worse than the other two so I have decided to leave that out. I've searched for this in the forums, but not many people run a foam filter. The popularity of K&N is apparant and most people cite the fact that it flows better/lasts longer. So what do you guys think about foam? Is the loss in flowrate made up for the superior filtering ability?

I'm asking this question because I need to replace the filter on my 1984 RX-7 GSL-SE. I'm currently looking at these two panel drop-in filters.

1) Foam air filter element made by Racing Beat
2) Cotton-gauze filter made by K&N (pricey!)

Alright, I hope this thread gathers the general opinion of the first-gen forum on air filters.
Thanks for reading and replying.

go k&n

heres how it works.

paper filter. As it filters dirt and other shit out of the air those particals fill spot on the filter. So the more its used the more restrictive it gets.

Foam will not flow any more than paper but it does not get clogged in this way, so it flows better for a longer amount of time.

K&N works on the principle that as air flows through the filter and around the cotton guaze, the oil catches the dirt. As the filter gets dirty the filtering becomes better but the increase in restriction is minimal

go k&n

very well put 82streetracer... i was going to say somthing along those lines:).. i could tell a big difference when i changed to a k&n filter. not really hp but it felt like nothing was holding the air back...
Cory

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Come on guys anyone else have opinions?

k&n, foam sucks a$$

The difference in flow between a new paper element and a K&N or foam filter is negligable. For the price of a K&N along with the cleaning/re-oiling kit you could buy at least 10 brand-new paper filters and not have to hassle with cleaning and re-oiling. Just an alternative viewpoint for your consideration. I actually LIKE the K&Ns, I'm just kinda lazy, and cheap. -WG

Like most anyone, I have used all 3 of the above methods of filtering. I have personally experimented with them all and come to my own conclusions. Of course, they are pretty worthless considering I have very little empirical data to back them up. However, I also have some input on some VERY high performance street vehicles due to some of the most knowledgable and credible people around, which should count for something.

I was over at Performance Motorsports a couple days ago checking out some of the projects over there. If you've downloaded a single street racing video, you've probably heard of Walser, SW, or Turbo Lexus (Clint) -This is where those cars are built. He is currently working on what should be the highest HP street 300zx in the nation, the fastest Viper in the nation, and some seriously fast Supras. NONE of them had foam filters. They all had cotton gauze (K&N or K&N style) filters to protect their very expensive motors. Take that for what you will, but I trust it as a good example to follow...

PS - If you have the urge to say something like "but those are pissed-on motors," or something along those lines...then by all means, PLEASE run a foam filter. For that matter, run NO filter! :stickpoke: Maybe if it was possible to get a rotary-powered street car to run 150+ traps in the quarter reliably, he'd play with them, but for Austin, that's Pro-Tech and MZM's chore.

Well, I drove my car for months with the paper filter that was in the car. I decided to put a K&N in when it needed to be changed and I felt a huge difference, much more pickup, but thats probalby mostly if not completely due to the fact that my old one was dirty as hell. If I were to do it again I'd still go with the K&N.

My buddy Pat Dolan, who's been heavily into autocrossing and kart racing for about 3 decades, strongly advises against foam filters. They're substandard even to paper in real world perfirmance, which is why they're the cheap filter alternative used by older pushmowers not high end performance cars.

bawahahahahaha.

i agree. there was a test somewhere on the internet with a skyline and a vacuum cleaner. the apexi and k&n tied for filtration and the apexi had slightly more gain in power (1-2hp). the foams didn't flow as well and didn't come close in filtration. a lot of people discredit the vacuum part, but it seems a legit test to me as its pulling through air and seeing how much gets through. just liek a motor.

I use the racing beat Foam element, it seems to work great for me! And its about half the price of a K&N

Thanks, where can I get a (cheap) K&N
 

Hey thanks everyone for replying. I guess I'm gonna get a K&N. Looking around online, I've found one for $56 bucks. The folks over at Racing Beat want $80! Does anyone know where to get a good deal on a K&N GSL-SE panel filter? The PN (part number) is 33-2016

Thanks again for reading and replying

Good Luck!

Is there a big price difference between the 12A and 13B filter prices? I bought a K&N for my 12A '82 for $47 CDN two years ago from the local PartSource guys. $80 seems pretty high for any filter.

ebay

Victoria British

If you're talking about a 4-port 13B, the air filter is the same as a 12A.

the GSL-SE K&N element is about $80. It's a rectangle, with larger swaths of filtering element than the relatively narrow ring filter on the 12A

SWEET!
 

I found this website through the K&N homepage (www.knfilters.com)

It's www.martelbros.com

http://www.martelbros.com/cgi-bin/st...e+1.3L+R2+F/I+

It's a GSL-SE 13B panel filter for $52.65 ! That's a lot cheaper than $80 (duh)

http://www.martelbros.com/cgi-bin/st....1L+R2+4+BBL.+

That's a 12A replacement filter (I don't know what it looks like, except that it doesn't look like a panel) And it sure does cost only (only?) $32.68.
I'm not quite sure if that's a good deal, but I think the 13B filter is quite a find. Anyways, I think they have FREE SHIPPING AND HANDLING, and free stuff is always good. Anyone else find a good place to buy filters?

Sorry, I should have been specific. I was talking to Matt in Canadian dollars, which is about $55 USD :)

I bought a filter for my 12a for only $37.