Limits of V6 Airbox/Stock Panel Filter

retmil46 · **Posted:** Tue Oct 09, 2007 12:13 pm

I believe we may have found the upper airflow limits with the V6 Airbox mod and a panel type filter that fits the stock airbox.

Before the dyno runs the other Saturday, I made sure to reset the Filterminder restriction indicator and blow out the Amsoil EAA filter before starting on the trip down. With everything that was going on that day, I simply forgot to check the indicator afterwards.

Yesterday, after sending off my ECM to Inmotion, I was doing a quick check under the hood and looked at the restriction indicator. It looked to be halfway between the first marking of 8" and zero. When I pushed the reset button, it popped back down to zero.

It seems that on the three dyno runs, clocking 150 to 152 RWHP, the beast managed to pull at least 4" H2O vacuum across the air filter.

This was with the V6 airbox mod, Amsoil EAA air filter with less than 3K miles on it and just cleaned, last stock factory reflash prior to F31/F37, MAF unplugged for ORM (for dyno runs only).

I'm wondering how much vacuum it would have pulled with the Inmotion tune in place, adding an extra 35 HP.

Granted, having David Dunbar do 3 dyno runs on your vehicle is as flat-out WOT as you can get, and it shouldn't be a factor in normal daily driving with a clean air filter. But it would seem we've found the upper limits of what our semi-stock air intake can do.

gmctd · **Posted:** Tue Oct 09, 2007 12:43 pm

Is your filter-minder calibrated in "H2O or "HG - for what you were doing, 4"HG would be more like it

Neb' mind - I'm still thinking big V8's...............................

onthehunt · **Posted:** Tue Oct 09, 2007 7:38 pm

4" is not much at all. I think it takes 25" for the filter to be restricted enough to change it. You probably pulled 4" just doing full power dyno runs through the stock system. Not even close to upper limits of intake system.

nescosmo · **Joined:** Sat Jul 14, 2007 11:17 pm **Posts:** 202

Open the hood and look right above it there is a rubber gasket that when you close the hood will restrict the air from the difflector, at list mine has it.
I took a telescoping mirrow when the hood was close and it was restricting the air..... Check it out.
:cry:

retmil46 · **Posted:** Sun Oct 14, 2007 12:02 pm

Rechecked the air filter indicator after doing a couple WOT tests with the Inmotion Stage II tune (

). Pulled the indicator down to 8" water vacuum.

I've developed a sudden craving for swiss cheese. :wink:

onthehunt · **Posted:** Sun Oct 14, 2007 7:24 pm

Will it make a difference? You have the old gas airbox set-up? Wonder how much water it would pull with the stock crd system? Maybe less?

Tinman · **Joined:** Mon Apr 10, 2006 10:45 am **Posts:** 308

Question is where is the restriction. Air box or filter? If its the box, no problem; start drilling holes. If its the filter, then we have a problem, need more surface area of filter media. What I'd like to see is a drop in cone type EaA with more surface area than the flat stock one. I'd also like to see on of those the the new Cummins too. (They make them but they are the oiled type elements, which I have no use for.) Speaking of Cummins, the newer airbox is very similiar to the CRD and in stock trim people are pulling down the filter minder regularly. In my case, I put in a cool air mod which is basically a 4 inch hole in the bottom of the air box with a tube to pull cool air from below the front fender. Now (with stock paper filter) I can't pull down the minder. So maybe that's all the CRD needs, an air box with more area to draw from. I've been considering drilling the bottom or our Libby air box for a while.

Jeger · **Posted:** Mon Oct 15, 2007 2:22 pm

Mitch....care to do a run without the filter in place? Take one for the team?

CATCRD · **Posted:** Mon Oct 15, 2007 7:01 pm

Jeger wrote:

Mitch....care to do a run without the filter in place? Take one for the team?

Or how about a run with a K&N, not that I'm advocating their use on a daily driver.

retmil46 · **Posted:** Mon Oct 15, 2007 7:38 pm

Well, crdmike quite a while back did the "swiss cheese" treatment on the bottom portion of his airbox - drilled several 1/2" ID holes in the side facing the fender well. He says that seems to have made quite a difference in it's ability to breathe.

I'm contemplating doing the same to mine, plus getting a roll of fiber filter material from the local hardware store that they use for house central air filters and attaching it over the extra holes as a prefilter to cut down on dirt and trash sucked in.

As Tinman mentioned, over on TDR people with late model 5.9 HO Cummins trucks have been experiencing similar problems with the stock air intake. My friend out in Wyoming with an '06 5.9 and a stock intake and filter can nearly peg his restriction indicator when he gets on the throttle. From reading thru the comments on TDR, seems to be a combination of both the stock filter and the airbox.

Guess that shows just how far DC went down the road of cost-cutting before the sell-off - they even managed to stick a crappy air intake on what is arguably one of, if not the, best selling and most profitable vehicles they have.

I'm already running an Amsoil EAA air filter, which seems to have been an effective remedy over on TDR, along with opening up additional inlets in the airbox. So it seems some airbox modification would be next in line.

Couple things I can try before breaking out the hole saw - I remember Ranger1 reported that removing the plastic water dam for the V6 inlet seemed to give something of a "ram air" effect at speed - I can try removing this, and also try removing the 90 degree snorkel as well, let it suck thru a straight hole. If either or both of these has a positive effect when doing a WOT, that would indicate that some additional air inlet area would make a difference.

retmil46 · **Posted:** Mon Oct 15, 2007 7:46 pm

Tinman wrote:

What I'd like to see is a drop in cone type EaA with more surface area than the flat stock one. I'd also like to see on of those the the new Cummins too. (They make them but they are the oiled type elements, which I have no use for.)

Hmmm, from looking over at the AEF website, they make the Super Stock IRF drop-in cone filter in a Pro-Dry version for '03-'07 Cummins now.

Tinman · **Joined:** Mon Apr 10, 2006 10:45 am **Posts:** 308

That's a good find retmil46. I knew they made an oiled element like that but not a dry one. Looks like they have 2 different types. Can't find any tech info that states what the media is and how good it filters. I'm partial to paper because it filters so good but just so restrictive. Using a large paper element is what I like. This AFE unit may be the ticket for the Cummins. Of course, I just ordered a EaA. I may sent it back and try one of these. I doubt the CRD market is big enough for AFE to R&D one of this type for the Libby. That'd be great.

DarbyWalters · **Posted:** Thu Oct 18, 2007 10:37 am

Did I miss it or did you run a "Stock OEM" filter for comparisons sake against the Amsoil EaA201? It would be nice to know the Stock vs Amsoil numbers.

0311_DoC · **Posted:** Thu Oct 18, 2007 12:32 pm

Since I don't understand half of the techno babble on this thread.. Does this all mean that the V6 airbox mod for the CRD isn't all its cracked up to be?

Cowcatcher · **Posted:** Thu Oct 18, 2007 12:43 pm

0311_DoC wrote:

Since I don't understand half of the techno babble on this thread.. Does this all mean that the V6 airbox mod for the CRD isn't all its cracked up to be?

I don't think it means that. What it means is that while the V6 mod helps the CRD would be happy if it could breath even more. If you don't do the V6 mod and you get into heavy snow or rain you will end up with a soaked air filter and dramatically reduced performance.

0311_DoC · **Posted:** Thu Oct 18, 2007 12:49 pm

Cowcatcher wrote:

0311_DoC wrote:

Since I don't understand half of the techno babble on this thread.. Does this all mean that the V6 airbox mod for the CRD isn't all its cracked up to be?

I don't think it means that. What it means is that while the V6 mod helps the CRD would be happy if it could breath even more. If you don't do the V6 mod and you get into heavy snow or rain you will end up with a soaked air filter and dramatically reduced performance.

ok that I understand.. Thanks for breaking it down Barney style for me :lol:

onthehunt · **Posted:** Thu Oct 18, 2007 6:57 pm

Quote:

I don't think it means that. What it means is that while the V6 mod helps the CRD would be happy if it could breath even more. If you don't do the V6 mod and you get into heavy snow or rain you will end up with a soaked air filter and dramatically reduced performance.

That is not proven unless someone has done a stock run with a restriction gauge and has numbers stating otherwise. I really doubt we'll ever see those. All air filters lose some flowrate in heavy rain and snow. I see it all the time during the winter. Snow can plug a filter fast. Never seen rain plug a filter but if your filter is already restricted it can add to it. No one has even proved that the v-6 box flows any better than the stock box.

brew1 · **Posted:** Sun Nov 04, 2007 3:28 am

I'm up late thinking about mods.

Interesting discussion you have here, especially for someone such as myself that is considering adding the V6 airbox.

Just a couple questions. Wouldn't a K&N filter flow more air than your paper element filters? Over on the TDI side, the K&N is shunned by many that are of the opinion that the K&N doesn't filter as well as a paper element and also kills the MAF, usually when folks don't read the directions and over oil the filter. None of the K&N haters I know of would dispute that it flows more air.

Second question. Even if the V6 airbox with whatever filter and modification you make to it, flows more air, will the intercooler be able to keep up with the increased airflow or will heat soak be an issue and require an intercooler upgrade?

gmctd · **Posted:** Sun Nov 04, 2007 2:03 pm

Correct - the K&N flows more air than the stock paper filter - BUT, it doesn't clean the air as well UNLESS it is oiled - most folks stop the oiling process B4 the original can of oil is emptied, due to the messy job of clean-up, dry, and re-oil - so, they're losing the inherent advantage of an oiled screen filter over a paper filter, for the advantage of a paper filter over the oiled type - ease of replacement\disposal = catch22.

The CRD airbox flows better than the V6 airbox - BUT the inlet is down low, where more of the after-spray of the
vehicle(s) you're following will be the heaviest, hitting the grille area with greater force, with greater volume entering the intake - dust, dirt, water, snow - whatever, but the denser liquid quickly reduces ability of the filtration media to flow air - get the intake up into higher real estate to reduce that effect.

Then, compare reduced air-flow event to WOT event to determine which configuration is suitable - how much actual time do you spend just cruising, and how much time at full throttle.

The airbox debate may be a matter of necessity depending on where you drive and incident of inclement weather - but, the DCX engineers didn't go cheaper on the CRD system, no matter what you may read - there's more components in the CRD system than in the V6 - components cost, more components affect the bottom line - the off-shore KJ CRD versions prolly got the V6 'snorkle' due to the increased probability of unpaved roadway in other countries, where increased reliability in adverse conditions takes precedence over stoplite racing.

You'll do more for increased air flow-thru by replacing that restrictive muffler - that will help to reduce EGT by allowing the hot exhaust gasses to quickly evacuate - the turbine and soot-trap helps muffle objectionable noises, so a good straight-thru muffler can be used to efficiently clear the pipe so the TD engine can develop more of it's inherent power - remember, it's an emissions-compliant system, with much factory detuning intended to help it sneak thru the lite-duty Diesel line.

Far as the charge-air cooler, if you're not racing, prolly removing it for a good cleaning out will keep it suitable for the little four-banger, no matter what the airflow - there's no room for expansion, and the a\c condenser completely covers it - note your IAT with a\c vs without a\c - the c-a cooler should keep IAT at ~ 20deg above ambient when the a\c is off - if you can keep IAT below ~150degF max, the engine will run better

If you wanna do a little street-racing, just turn the a\c off for the run - that helps a bunch.

BTW - our little mule had the Edge module and the magnaflow muffler - was fairly peppy - installed the Suncoast\Transgo, and it was much better - uplugged the MAF to throttle the EGR, and it's a whole bunch peppier - quicker throttle response, and all the stuff that goes with clean air intake

Cowcatcher · **Posted:** Sun Nov 04, 2007 2:13 pm

It is important to note that the non-North American Liberty CRD pre 2004 (maybe pre-2005) had the V6 air box.

Limits of V6 Airbox/Stock Panel Filter

Who is online