Air filters - why not plastic? - Page 2 - Fuel Economy, Hypermiling, EcoModding News and Forum

Funny · 04-10-2008, 01:33 PM

Quote:

Originally Posted by Otto

So, Funny, what filters do you recommend to use, and to avoid?

AC Delco (A division of Cummins I believe) usually have a very well built, solid filter. As does Baldwin and Donaldson, in that order. When you buy the filter, don't be afraid to take it out of the box and inspect it. The pleats should be straight, the corrugations (if it has them) should line up (that's so the air filter doesn't collapse under load, and keeps the pleats separated so the filter lasts longer), the plastisol gasket should have no gaps or bubbles so you can have a tight seal, and the glue that holds the pleats together at the ends should be even and have no gaps in it.
I'll have to take a picture or two of a good filter because just describing it sometimes isn't enough for some people. I'm a "I'll believe it if I see it" kind of a guy myself, so don't just take my word for it.
Get reviews on the filters you plan to buy. Don't always believe what manufacturers tell you, K&N is a good RACING filter, nothing more, nothing less. It is not made for longevity of the engine.
We're all about longevity

.

LostCause · 04-10-2008, 07:34 PM

Minimizing waste is always a noble task, but I don't see a very pressing need for a reuseable filter.

A normal filter should last 30,000 miles. Cars probably average 150,000 miles during their lifetime, so 5 filters (@ $8 each) will total $40.

Someone who blows compressed air backwards through the filter (being sure to seal off the engine side from contamination) could probably run their filter 45,000-60,000 miles. At 150,000 miles, 3-4 filters (@ $8 each) totals $24-$32.

What about waste? 3-4 airfilters is very minimal waste to begin with (6 x 8 x 1.5 inch box) and they are made of paper. I don't see why an airfilter cannot be recycled, at least the paper element (which is >80% by volume).

For those who visit dusty sites, then a low efficiency, cheap, removable plastic pre-filter would help keep the primary filter clean. Interesting conversation, though. I would be interested in an efficient, reuseable filter if they did become available.

- LostCause

Funny · 04-11-2008, 02:23 AM

Here's some data I gathered on an AC Delco panel filter at work today.

I took apart the filter and was able to obtain ten samples (A-J) that were usable. I then ran CFM (Cubic Feet/Minute) tests and averaged a flow of about 65+. Not bad flow for a panel filter, but that is a Flat sample, it would be folded back up in a pleat, so flow would be slightly reduced.

The Mean Flow Pore (MFP) tests on the samples and concluded that it had about a 31 micron MFP. That is the highest point on the bell curve for the filtration, so thats the average it will filter down to.

The base weight is just the Pounds per Ream (3000ft^2).

I also included a picture of the side of the box for reference, I'm not even sure of the application for this, just know that it's for a car or truck

.

Hope that helps a little, I know how frustrating it can be when a pompous wind-bag gets on a forum and just starts spewing data and not substantiating it

. I am not one of those.

Just so I don't that I don't have this one come back and bite me in the behind, I will not be able to get the exact figures for the K&N filter unless I was to run a flat sheet test for beta ratios. My boss told me today that comparing paper media to oil impregnated cotton is like comparing apples to oranges. The only way to compare the two would be to get betas. I'm not an engineer at this company, just a lowly tech

,so I can't request it myself. I'll ask my boss if it would be worthwhile pursuing a beta test on it for a reference point

.

Also, just a totally different thought on this filtration issue. We haven't discussed Face Velocity. In short, the lower the face velocity, the slower the particles are moving and as such, more particles are captured.

How do you lower the face velocity you ask?

Well the easiest (and only economical choice

) is to get a larger filter. Like a cylindrical or conical filter, over sized for the application.

Again, thanks for the interest in this thread, it's one of my passions.

WTFM8 · 04-11-2008, 01:18 PM

FYI: AC Delco is a subsidiary of General Motors.

Peter7307 · 04-11-2008, 10:35 PM

Quote:

Originally Posted by LostCause

Minimizing waste is always a noble task, but I don't see a very pressing need for a reuseable filter.

What about waste? 3-4 airfilters is very minimal waste to begin with (6 x 8 x 1.5 inch box) and they are made of paper. I don't see why an airfilter cannot be recycled, at least the paper element (which is >80% by volume).

- LostCause

My thinking is this is one step on the road.
By reducing the "one use" mentality many people have for this item not only will it help reduce pollution but it may even get some to think (I live in hope)

My parallel is like increasing fuel efficiency. You get there on small gain at one time.
Is it worth it on one car and will it make an appreciable difference to the overall picture?
Probably not. But if every car had one it certainly would.

Pete.

AnDoireman · 04-15-2008, 11:36 AM

When they mention K&N filters are useful under a high load, just how high a load are they talking about? Is it the sort of high load a fast driver of a modded car won't see?