Gasp..must.. get ...more ...air

BiodieselJeep.com · **Posted:** Sat Feb 09, 2008 4:43 pm

I happened to clean the airfilters on both my CRD and my 99.5 Jetta TDI just today. OUR CRD AIR INTAKE IS SUCH A JOKE, no wonder nobody gets much boost. The TDI airbox has twice the size filter dimension and the VW OEM air filters have pleats almost twice as deep....4 times the air intake! And that for a 1.9 liter TDI engine compared to our bigger 2.8 liter CRD.

We have GOT to figure out a better way to get air into our oiler. Amsoil is a great start...

.. with god is my witness, I vow that my CRD will never go hungry for air again!!

All apologies to Ms O'Hara

gmctd · **Posted:** Sat Feb 09, 2008 8:42 pm

I installed a Filter-minder in ours - never even shows first-stage yellow after full-throttle runs - the air volume is there - just keep it cool........and dry......................

geordi · **Posted:** Sat Feb 09, 2008 10:22 pm

I have seen 33-34psi in my Jeep, and spikes as high as 37... So I don't know where you are getting that the KJ isn't getting enough air. Also, more surface area b/c of deeper pleats is a good thing, as it means lower air SPEED through the filter, which will lead to better filtration. But deeper pleats don't do one single thing to increase the air VOLUME. Now deeper pleats could offer longer filter life, or potentially more airflow when heavily clogged, as the suction would be spread out over more area... But that is a sub-optimal condition, and the airbox is not designed with plugged operation in mind.

DarbyWalters · **Posted:** Sat Feb 09, 2008 11:09 pm

Then we should have NO PLEATS...The extra number of pleats and length of pleats adds to the filtering area...but it also means the finite amount of air that comes in the intake has more surface area (opportunities) to pass thru...making it less restrictive. (Speaking of the EaA Amsoil Filter)

geordi · **Posted:** Sun Feb 10, 2008 12:10 pm

Uhm, that is the exact opposite of what happens. If you want more filter surface area (for better filtration) then you WANT pleats, and you want them as deep and wide as possible.

Take three pieces of paper, and fold one of them into 1/2" pleats. Doesn't matter which way. Now, take the second sheet, and do it again, same direction as the first. Place the two folded sheets next to each other, with the flat sheet just sitting for comparison.

See how the two folded sheets are taking up the same amount of room on the table as the flat sheet... Yet there is twice as much paper being used? Yea. That's surface area. More surface area on the filter is a good thing, but it doesn't change the total air needs of the engine. More filtration is better, don't you think?

Goglio704 · **Posted:** Sun Feb 10, 2008 12:20 pm

Unless they are so tightly packed that air can't get to the side of the pleat, more pleats filter better and have more flow capacity.

chrispitude · **Posted:** Sun Feb 10, 2008 12:22 pm

If you have a restrictive media (like filter material) which results in a pressure differential when pressure drop is applied to one side, then you want to maximize the surface area (the pleating) to keep the pressure loss down. The less pressure loss you have, the greater the flow rate (which is volume per time).

Here's one way to think about it. Forget about the pleats completely. Let's say you have one square foot of clogged-up filter material that barely basses a trickle of air. Now, let's say you have 1000 square feet of that same clogged-up material. When you attempt to draw a flow through both pieces of media by applying a pressure drop to one side (like an engine does, since it's just a fancy fuel-driven air pump), the larger piece of media will have a greater flow rate than the smaller piece of media.

To get a larger piece of filter media into an airbox, we pleat it.

I run the Amsoil EaA201 air filter with satisfactory results in my stock CRD airbox. After about 20k miles, it's still in great condition without any visible dirt accumulation.

- Chris

gmctd · **Posted:** Sun Feb 10, 2008 1:15 pm

If it's performing its assigned task, it is way more stopped up than you may imagine - no way you can put 20kmi on a filter and not have an immense quantity of silicate particles in the interstices - up to 50% clogged can appear as clean, until you get down in the pleats - I'd suggest pulling it for a good cleaning, if you have not - just firmly tap the dirty side flat-faced up against a tree or some suitable surface, and watch them little particles scramble for their very lives................

BiodieselJeep.com · **Posted:** Sun Feb 10, 2008 4:11 pm

geordi:

So, I take it you run a stock (ish) air filter. Just for kicks, get an Amsoil and compare.

Steady state is one thing, what about acceleration? Friction (the filter) will slow the airflow increase (increase in rate) which will be noticable in the "butt dyno" but not on the scanners. I would assume that a better (aka larger, cleaner) filter would allow faster airflow acceleration....reducing some component of the "lag" affect.

Or, I could be wrong. But I trust VW vs DC anyday...and I'm guessing VW knew something.

Threeweight · **Joined:** Mon May 14, 2007 5:57 pm **Posts:** 679

I run WIX/NAPA air filters... more/deeper pleats than Mopar/Fram, same price. I always swap filters at 10-15k, regardless of what it looks like. Earlier if I run in a lot of dust during summer fishing trips.

DarbyWalters · **Posted:** Sun Feb 10, 2008 6:00 pm

geordi wrote:

Uhm, that is the exact opposite of what happens. If you want more filter surface area (for better filtration) then you WANT pleats, and you want them as deep and wide as possible.

Take three pieces of paper, and fold one of them into 1/2" pleats. Doesn't matter which way. Now, take the second sheet, and do it again, same direction as the first. Place the two folded sheets next to each other, with the flat sheet just sitting for comparison.

See how the two folded sheets are taking up the same amount of room on the table as the flat sheet... Yet there is twice as much paper being used? Yea. That's surface area. More surface area on the filter is a good thing, but it doesn't change the total air needs of the engine. More filtration is better, don't you think?

My comment on NO PLEATS was in jest. The more surface area, bigger pleats and more of them, will filter better AND let more air in for a longer duration/period of time. As to the engine needing a better filter (with more flow)...of course it is better and it could possibly get more air into the engine. Every point is a limiting factor along the trail...a filter with more surface area can and will supply more and cleaner air up to the engine limits. I think the stock filter on the CRD is definitely too restrictive...IMO

litton · **Posted:** Sun Feb 10, 2008 6:28 pm

It would seem that a filter minder is the first step. If you're not getting enough air.....it will tell you. Sorta takes the subjectivity out of the equation.

BiodieselJeep.com · **Posted:** Sun Feb 10, 2008 6:41 pm

litton wrote:

It would seem that a filter minder is the first step. If you're not getting enough air.....it will tell you. Sorta takes the subjectivity out of the equation.

But, what about my supposition that scanners/filter minders only measure a steady-state flow and not the ability to INCREASE that flow "spool-up" quickly?

Anybody? Bueller? Bueller?

I think Amsoil is a START but we must need more.

geordi · **Posted:** Sun Feb 10, 2008 8:05 pm

BiodieselJeep.com wrote:

geordi:

So, I take it you run a stock (ish) air filter. Just for kicks, get an Amsoil and compare.

Steady state is one thing, what about acceleration? Friction (the filter) will slow the airflow increase (increase in rate) which will be noticable in the "butt dyno" but not on the scanners. I would assume that a better (aka larger, cleaner) filter would allow faster airflow acceleration....reducing some component of the "lag" affect.

Or, I could be wrong. But I trust VW vs DC anyday...and I'm guessing VW knew something.

Is the Amsoil anything like a K&N? (I really am asking, I have no idea)

If it is, no thank you. I like the increased flow of a K&N in theory, but the added crap that passes right through like the filter isn't there... Will cost an engine eventually. I am running a stock filter, and since I can't compare my KJ to a non-F37 type, I have no point of reference for what an un-crippled engine might feel like. I'm still stock except for the SEGR. That was the first mod I bought, and I got that before I even owned the Jeep! :lol:

I have almost 40k on the KJ right now, and I don't honestly know when the last oil change or filter change was. I'm going to do a full tune-up and change all the filters myself at 40k, which will mean that at a minimum, the oil and filters have 8k on them, as I bought it with 32k on the ticker. From then on, I will probably run 10-12k oil changes, and air filter as needed. I typically check that every few months, and change it after pollen season here in Georgia no matter what. 40k should be just about at the end of pollen season this year.

nursecosmo · **Posted:** Sun Feb 10, 2008 10:46 pm

I had to laugh last time I went into the autozone store. They had the K&N ping pong ball machine there at the counter and the guy behind the counter was trying to sell me on how great the K&N airflow was. The machine showed an obvious improvement in flow but when I held the K&N up to the light I could literaly see through it, some holes were so big a grain of sand could have passed through it. When I pointed this out to the salesman he said that particles that small would not hurt the engine, but that insects and leaves were more damaging(ya right). He can keep his high flow K&N.

litton · **Posted:** Mon Feb 11, 2008 12:01 am

BiodieselJeep.com wrote:

litton wrote:

It would seem that a filter minder is the first step. If you're not getting enough air.....it will tell you. Sorta takes the subjectivity out of the equation.

But, what about my supposition that scanners/filter minders only measure a steady-state flow and not the ability to INCREASE that flow "spool-up" quickly?

Anybody? Bueller? Bueller?

I think Amsoil is a START but we must need more.

The filter minder is only a little vacuum gage. It would registar yellow or red even if the need was only brief....probably less then a second. My guess is that it's a very good indicator of a restricted air flow no matter what the reason.

BiodieselJeep.com · **Posted:** Tue Feb 12, 2008 2:14 pm

litton wrote:

The filter minder is only a little vacuum gage. It would registar yellow or red even if the need was only brief....probably less then a second. My guess is that it's a very good indicator of a restricted air flow no matter what the reason.

Oh, so does it "stick" and hold the lowest pressure reading to see later? That's cool, just the thing. Got a link?

retmil46 · **Posted:** Tue Feb 12, 2008 3:12 pm

I've got a V6 airbox and intake installed, along with an Amsoil air filter and a Filterminder gauge.

Only two times has that beast ever registered any kind of reading - when David Dunbar wrung it out on 3 dyno runs, and when I did some semi-WOT trials after getting the Inmotion Stage II tune.

And both times, it was just enough for the Filterminder to lock in a reading - halfway between zero and 8" H2O vacuum.

I did the "swiss cheese" treatment on the bottom half of the airbox, on the side facing the fender. Filterminder hasn't budged since.

Zonie · **Posted:** Tue Feb 12, 2008 7:30 pm

How many holes, Mitch, and what size drill bit?

DarbyWalters · **Posted:** Tue Feb 12, 2008 8:03 pm

I also did the 2002 Air Box Conversion and the Amsoil Ea Filter. I also built an "air scoop" to get more air at speed ect. You can pass your cursor over the grill to see the location of the Grill Blocks and Air Scoop/Air Catch.
http://s205.photobucket.com/albums/bb97 ... P_0209.jpg

Gasp..must.. get ...more ...air

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