Minor crack to the air box, should I do the V6 upgrade?

kjcrd117 · **Posted:** Sat Jan 12, 2008 12:56 pm

First off, the crack isn't very substantial, and the lid seems to be seated normally. Basically, I went to flip the left clip to secure the lid, and the area where the leftmost tab goes into the lower half of the air box cracked.

It can be seen in this picture (barely):

Seeing as the seal all seems well, I know I can go a bit before I address the problem, but I am just wondering if I should do the V6 air box upgrade.

I could just as easily get the stock replacement CRD lower half and be done with it, but I want to go with the "best" option.

For reference, I drive about 50/50 city/highway, at least 60 miles a day, and drive through rain and snow frequently enough (living in western Pennsylvania).

I know there are different views, but what is the latest from those who have already performed the mod? Go for it? Stay away? No opinion?

I'm re-reading all of the old threads on this topic, but would appreciate any more recent input anybody can provide.

Thank you.

gmctd · **Posted:** Sat Jan 12, 2008 3:00 pm

That's a latching area, not a sealing area - you'll need to worry if that creeps across to the other side of the slot and into the sealing lip area, but I don't think it will - you can pull the lower box, ruff-up the area underneath that lip, use black polyurethane glue to contain the crack, dries to hard rubber-compliant consistancy - otherwise, V6 airbox is up to you

FYI - DCX spent extra money on the CRD box and associated bits and pieces than the V6 version - that would include the plastic pieces and fasteners required for ducting thru to the grille area - they could have simply used the V6 version as is, since it had been around for several years and was in ready stock - if you're having trouble with damp filter elements, the V6 version seems to solve that problem - the CRD version was designed for the increased airflow required by a Diesel engine - even one strangled with EGR.

kjcrd117 · **Posted:** Sat Jan 12, 2008 4:05 pm

Thanks for the reply.

Yeah, I was thinking of just trying to fix the crack by melting (via soldering iron or a plastic welder), but I think your directions are more sound. I think I'll just repair that lip for now (even if it isn't really necessary) and then go from there. I haven't really paid much attention to the filter getting wet, so maybe I'll monitor that for a while before I make my decision regarding the V6 upgrade.

I do understand what you are saying about the qualities of the new design. It does seem dumb that they would spend extra money on engineering, design, and manufacturing if it wasn't necessary. Then again, I have to scratch my head when I look at the catalytic converter and muffler that they decided would work equally well on both the gas and diesel setups. It'd be nice if they had spent as much thought on improving that on the CRD as they did with the air box.

In any case, I'm not really drawn towards one option or the other at the moment, so I just wanted to see what the latest thoughts on the mod were.

I'd appreciate any input on the topic from anybody who can shed some further insight as well.

Thanks again.

gmctd · **Posted:** Sat Jan 12, 2008 8:01 pm

That's actually an oxidizing convertor, not a catalytic - it's mainly a soot trap, to catch the heavy particulates - then, when you get up on the hiway for awhile the intense heat cremates the particulates, and they're blown out as harmful ash with the exhaust gases - enter ULSD and low ash motor oils, intended to reduce the amount of those particulates, which also helps with your EGR, reducing those nasty solids in the intake manifold

kjcrd117 · **Posted:** Sat Jan 12, 2008 8:15 pm

Cool, thanks for correcting/informing me.

I guess I do remember now that you can't use a catalytic converter unless you are running something like biodiesel (or maybe ULSD?)?

I do plan on doing a bunch of the mods. I have a ProVent and Racor fuel filter assembly sitting here, along with a box of hoses, fittings, and parts from McMaster-Carr, so I will put them on in the upcoming weekends after I get my state inspection done next week.

I thank you and everyone else for all of the information you have shared. I don't think I can count how many pages of information I have printed out from here. All great stuff to make this vehicle run the best that it can.

warp2diesel · **Posted:** Sun Jan 13, 2008 12:28 am

Our 2.8L CRD engines can ingest about 1 tea spoon of dirt before the Engine is dusted out. I was shown a bunch of documentation on International DT-466 engines that were dusted out by 1 table spoon (3 tea spoons) of dirt. When I had my shop I replaced rings on several VW Diesel that were dusted out and lost compression by having air cleaner clips pop off.

Steve :wink:

kjcrd117 · **Posted:** Sun Jan 13, 2008 12:39 am

Steve,

So what are you telling me? Where do you stand on the 2002 V6 airbox versus the 2005-6 CRD airbox? I realize that one teaspoon is a third of a tablespoon, but am still unsure if I should jump into the V6 camp.

- joe

warp2diesel · **Posted:** Sun Jan 13, 2008 1:03 am

To do the proper analysis you would need to have a manometer stuck upstream from the air filter and mount the top end in your cab. Then:
1) Seal up the crack in your CRD box, top off the fuel tank, weigh your self, and drive up a hill with the throttle in the full throttle position and mark the manometer.
2) Install the V6 air box very fast before any weather conditions change, top off the tank, weigh your self and drink some water to make up for any loss of weight resulting from the sweating you did from swapping the air boxes, and again drive up a hill with the throttle in the full throttle position and mark the manometer.
3) If you want a Masters Degree and want to write a big paper, you will need to repeat the two tests above at least six times over different weather conditions. Record every variable you can think of and then write your big paper and be ready to defend it in front of a bunch of PHD egg heads.
4) If you don't want a Masters, let us know what you find out , we would all like to know how many millimeters of water column differential there is between the two air boxes. This information may help us trim a few milliseconds off the quarter mile at the drag strip.

Since I have my Masters and done stuff like this before and dazzled the PHDs, I will run my stock air box and save my money to have my ECM flashed after I install my ORM kit I am building. My electric fuel lift pump has added the most performance of any thing I have done so far.

Steve :wink:

kjcrd117 · **Posted:** Sun Jan 13, 2008 1:19 am

Steve, thanks for the injection of humor. Was just wondering if somebody had done something as simple as a CFM measurement at a set speed between stock and V6. That in and of itself would probably tell me the answer I seek.

Yes, I know barometric pressure and moon sequence, etc. may matter, but like I said, I wanted to go with the best option at the time. I guess I'll stick with the stock CRD setup for now.

Steve, don't you care about a millionth of a millimeter of mercury? With that kind of precision, I could sue for three quadrillion dollars...or whatever that BS lawsuit is for. In any case, I see what you are getting at, but I'd still like to see a simple CFM flow between stock and V6...that should spell out the obvious.

- joe

warp2diesel · **Posted:** Sun Jan 13, 2008 1:53 am

A flow bench uses one big tapered tube type flow meter to test the CFM flow.
Dwyer http://www.dwyer-inst.com/ may have what you want if you want to pay for it through the nose.
In all truth there are so many variables that can change the CFM flow through the air boxes, the flow bench test with out an air filter may be the only way to make a absolute determination.
I suspect the test flow through the air boxes would exceed the demand of the engine before any turbulence caused a loss of flow.
Since none of us are stupid enough to run our CRDs with out an air filter element, the flow bench is the only way.
One thing I have noticed about both the 2002 3.7L gasser and the 2.8L Turbo Diesel is they both use the same filter element which is most often the limiting factor on air flow.
K&N filters offer more flow but are weaker on dirt removal.
Therefore, selecting the filter element with the least restriction and most cross section of filter paper would produce the most cost effective results.

Steve

retmil46 · **Posted:** Sun Jan 13, 2008 11:43 am

Main reason for the V6 airbox mod is that quite a few people were seeing their air filters turn black with dirt in short order (ie, in between oil changes), or end up soaking wet with 1/8" of standing water in the bottom of the airbox after driving thru a heavy rain.

One gent, RFCRD I believe, actually ended up with his air filter caked over with road salt from winter driving in Ohio. It was caked over to such an extent that he considered it probable cause for causing his turbo seals to fail, dumping a quart of oil every 1000 miles into his air intake and requiring replacement of the turbo.

Mine was the same way - air filter would literally turn black in between oil changes, and while I never checked it immediately after driving in a heavy rain, I could see the "ring around the tub" watermark in the bottom of the airbox where there had been upwards of 1/8' to 1/4" of standing water in it at one time or another.

This problem isn't so much to do with the stock air box or filter, but with the stock air INLET. Genius that designed it didn't realize that the gaps around the headlight and foglight in the grille would allow water/dirt/etc to completely bypass their whamerdyne baffle arrangement and dump straight into the inlet tube for the airbox. And if the seals for their baffle arrangement weren't installed correctly at the factory, you could end up sucking in even more crap off the grille.

Going to a V6 airbox and inlet has at least doubled the useable life of an air filter in my case, if not more, and no more "ring around the tub".

As far as air flow - I have a Filterminder on my airbox. First time I saw the beast move was when David Dunbar did 3 dyno runs on it, sucked it down to 4" water vacuum. That was with a stock tune with an Amsoil air filter in the V6 airbox and ORM. After getting the Inmotion tune, I was able to pull it down to 4" water vacuum when I did anything resembling a heavy throttle takeoff pulling out into traffic. Before the last trip to TX, I did the "swiss cheese" treatment to the fender well side of the bottom half of the airbox - drilled a dozen or so 3/8 to 1/2 inch holes to let in more air. Even with giving a few "demonstration" runs since, Filterminder hasn't budged.

kjcrd117 · **Posted:** Sun Jan 13, 2008 12:28 pm

retmil,

So basically you're saying the V6 mod is good enough, even without drilling any holes in the airbox?

- joe

retmil46 · **Posted:** Sun Jan 13, 2008 1:15 pm

kjcrd117 wrote:

retmil,

So basically you're saying the V6 mod is good enough, even without drilling any holes in the airbox?

- joe

For normal driving with a stock tune, I'd say yes. As far as towing, no idea - I don't have the tow package and have never towed with mine. Only time I've seen the V6 airbox exhibit any restriction with the factory tune, as indicated by the filterminder, was in the extreme situation of a balls-to-the-wall dyno run done by a professional operating the vehicle.

With an Inmotion tune or performance module, where you're trying to pull out significantly more HP/torque (up to 30 HP increase with the Inmotion if mine and Ranger1's dyno results are any indication), especially at lower rpm's, you COULD end up hitting the upper limits of air flow in daily driving with a heavy foot on takeoff. But then again, I only just hit the limits - just enough to make the filterminder register and lock in a reading that it had seen something resembling a vacuum or restriction in air flow.

FWIW, Ranger1 told me that with his Eqqus scan tool he'd noticed a difference in air flow at idle between a stock paper filter and the Amsoil synthetic filter - the Amsoil filter registered 0.1 lbm more airflow at idle than the stock filter. No idea what this equates to as far as restriction or CFM airflow.

In short - no, drilling holes in the side of the V6 box isn't a necessity, should be entirely adequate as is. And the main reason behind the V6 airbox idea wasn't to improve air flow, but to keep from sucking a bunch of crap and water into the air filter - ie, reliability and longevity.

Minor crack to the air box, should I do the V6 upgrade?

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