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CAI or Drop In Air Filter?

1K views 19 replies 9 participants last post by  rubberfish 
#1 · (Edited)
Got a 2009 6.7 with a 5" TBE and a WCC high flow intake horn and looking at if it's worth it or not to upgrade the intake system or just replace the filter I'm running? I'm looking for better mileage and to support a few more HP.

I have a AFE Magnum Force CAI with a Pro 5R cone filter off my 2004 5.9 DR . It's got the steel box and the filter is old and a little crushed but I could buy new filter. I measured the openings on the intake tube and it's 3.75" ID at the turbo and 6" at the filter.



I'm currently running stock box, no baffle, with a WIX 46930. It's got 50k on it, ZERO dust in the stock tube but filter needs to be replaced.....

So what's a better set up for mileage and to support a few more HP...

1) stock air box with
A) Wix 46930
B) Mopar Heavy Duty 53034249AA. ( Might be the same as WIX?)
C) Run a 5.9 Drop in that's not as thick.
D) K&N conical drop n E-0784.
*Note: I've tested air filters on my motorcycle in one of the harshest environments known and Amsoil nano dry sucks (replaced 5 under warranty, they all leaked). AEM Dry Flow brute force, leaked after 3 days, and I now run a K&N oiled with Maxima Fab-1 for over 3 years with ZERO LEAKS OR DUST. Even after servicing multiple times. All filters I tested ran an outerwears prefilter clamped over the filter boot.

2) AFE magum force with PR 5 filter with outerwears

3) Something else?

I've read through over 40 threads, most are old from 2008 through 2012, and I can not find any Dyno tested info on one filter/set up vs another looking at what filter flows best while still getting no dust in the intake tube. If you could point me in the right direction that'd also be great.

If you have an opinion and want to chime in please back it up with facts.

Thanks
 
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#2 ·
I'm curious... did the AFE help power and mpg on the 04? I don't care for those kind of filters, especially the cleaning and oiling. Calling those intakes an 'upgrade' is very questionable. A clean 4" thick oem paper element is hard to beat. I've done a LOT of resistance measuring with a water column and I've seen resistance actually go up with aftermarket systems.
 
#3 ·
Hi BFD,
I'm not 100% on how much just the filter helped, I did the 5" TBE, a Hot Juice, and the intake all at the same time. Loved the truck, got 20 mpg avg, even towing a small 14' open trailer.

On your testing, you talking about using a flow bench?

I was thinking heads up dyno results on the same set would be more real would vs flow bench numbers as there's a lot of other variables to making HP on the truck vs one dimension on the bench.
 
#5 ·
The only way to increase air flow without increasing the size of the filter is to lose filtration quality. The 4" oem filter from a reputable brand is the go to unless you like dust where you don't want it.
 
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#7 ·
KRS, your making the assumption that the current material that is not letting particles through is the at minimum amount of restriction possible, it could be over restricted. In other words, depending on material and structure you may be able to have less restriction (more air flow) but still catch most all particles.

Also your not talking in to consideration differentials in material properties and or oils used, or structure, but this is all conjecture, that's why I'm looking for tested results not theory.
 
#8 ·
The benefits you are chasing are negligible in comparison to the reduced quality of filtration. Been down that road when I was younger and more easily manipulated my marketing. S&B oiled and dry, AFE dry, etc. All of them showed no gains. Cost more money than they saved and a pain in the ass to clean and re oil or just clean. Always saw dust on the clean side of the filters.
 
#12 ·
Filtration is to keep dirt out of the engine. Oil analysis has silicates tested and those fancy free flowing filters don't filter and you wind up with worn internals. Thanks but I'll go for proper filtration and let the turbo do it's job
 
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#14 ·
It doesn't even really make much of a difference(other than how much you hear the turbo) unless you're running more fuel or a larger turbo. Until that point you're better off with just the best filter you can get. The stock setup is a "cold air intake". If you want to upgrade it go with an afe intake tube, it'll be the equivalent to one of the aftermarket CAI setups.
 
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#15 ·
Wix 4” pleated filter & OEM box offers the best filtering over everything else in mild builds around 500hp. This is the general consideration on this.
On the contrary, I ran a Banks (K&N) filter for probably over 150k before I switched back to OEM because of possible Dustin g issues with the motor. BTW the original 5.9 is still running good at 672,000km’s so I don’t think the K&N hurt as much as others claimed it would
 
#16 · (Edited)
Hardway (EDIT: sorry, it was FirePunk, not Hardway) did a video series a while back and showed a stock 3rd gen airbox, and a 4th gen airbox, and recently a “5th gen” airbox, will reliably support 550rwhp on a 6.7 68rfe truck with the stock filter. At nominal flow, any filter will probably be fine. Heck, at moderate flow there’s not much difference in the data concerning 95%+ filtration down to a micron size which won’t risk chewing up the turbo vanes’ leading edges. Where the difference comes in isn’t even max flow: all the aftermarket filters GROSSLY outflow by a statistically significant margin the stock filter. But where they fall off is their filtration effectiveness at or above the stock element’s “filtration at max flow” rate. The stock filter remains well over 90% effective at max flow, whereas the best filter I recall which came the closest was the S&B dry in the sealed box was several percentage points lower at the stock fleetguard element’s max flow rate. The PDD filter isn’t far behind, which at about half the price of the S&B is something I think is worth considering. An oiled element on an oil burning engine is just a bad idea waiting to happen if you ask me, but that’s my two cents. I ran a K&N on my 06, serviced religiously like I always have on my gassers going back to my dirt bike and race bike days, and in under 30k miles there was wear on the turbo vanes I couldn’t see - but I could feel it. Remember, force equals mass times velocity, so more velocity means you need either a more restrictive filter to catch an equal percentage or more surface area at the same effectiveness (which you can’t have with a fixed turbo inlet size anyway) and the aftermarket filters just aren’t there. They flow like crazy but they sacrifice filtration to achieve that flow. And in the vast majority of trucks, it’s flow we neither need nor will ever use.

Granted the K&N is the only one I have personal experience with, but looking at the other cheaper options and their filtration-at-flow rates (which it’s been a while since I dug thru the flow data, and now can’t find it again) I’m definitely not risking a $15,000 engine on a $20 filter just to save five bucks every 10,000 miles or get another 100 cfm flow that I don’t need anyway.

Totally understand the bling factor though. Feels good to pop the hood and see an obvious speed part staring you in the face. If you do it, just service it frequently and keep a close watch on those compressor blade leading edges.

Hope this helps. Good luck!
 
#17 ·
Thanks pozzinator, good info there. Probably just stick to the Wix, really tired of 14mpg on a truck that should be getting 20mpg not towing and sub 10mpg while towing 6k lbs, especially at $6 a gallon.

Just put on the 5TBE and the WCC horn, and dropped the cooler so we'll see what happens to mpg with those updates. I was reading a boost tube (shibby or WCC) will also incease milage?

I saw/read grid heater plates do not affect performance & mileage??? Mines pretty caked up just not sure if the juice is worth the squeeze to remove it? Anybody see mpg increases from GHD?

Thanks KHS, I'm running a Baldwin BF1212 water & a Donaldson P551313 fuel filter on a custom frame mount set up I made. No pump like the fass just passive filtration.
 
#18 ·
I had my new 97 for 2 years and I put on a bigger turbo, plate and other pump mods and a K&N dropin. 3k later it was due for an oil change. I pulled the turbo hose to get to the oil filter and there was dust in the hose and turbo. That's when I checked DPs with a 25" Magnahelic on different filters on that truck. Redline/wot runs... a new paper filter was 17" wc (about the point the filter minder started moving) and K&N was 11" wc.
I got a Fleetguard catalog and I found the biggest round element that would fit and I made a round neck for it. I hooked up the Magnahelic and went for a drive. At first I thought I had the tubes reversed on the gauge and then I figured out at higher speeds, the fan makes the under-hood pressure positive and it makes for ram induction... at times, I had higher pressure on the outside of the filter than on the inside. That filter was 3" wc DP.
Later, guys were using a BHAF that was smaller than the filter I chose but theirs had a round neck molded on the ends already.
Then, I had an 03 and I moved the battery so I could use an even bigger filter (2 round elements, end to end. Those filters were 1.2" wc DP at redline/wot.
My 12 had an oily rag filter/CAI and the PO also gave me the oem paper intake. The freshly cleaned, but not yet oiled, oily rag intake had higher DP than a new 4" paper element in the oem intake. That truck was the first time I started measuring static at the turbo mouth and I also measured DPs of the filter boxes and the DPs of the tubes between the boxes and the turbo, so I could play with the oem turning vane, with different intake parts combos. I found it's an instant detriment to replace the oem tube that has a turning vane with a CAI intake tube that doesn't have the vane.
Long story short... I had 36" wc static at the turbo mouth, with the oily rag CAI intake, and I got it down to 18", with my 2 round elements and by building turning vanes in the 4" CAI tube.
All the screwing around I've done with intakes and all I've ever noticed was a little better spool up but NO power increase on my timed empty runs or on my hills, towing. That money goes a LOT farther, other places!
 
#19 ·
I had my new 97 for 2 years and I put on a bigger turbo, plate and other pump mods and a K&N dropin. 3k later it was due for an oil change. I pulled the turbo hose to get to the oil filter and there was dust in the hose and turbo. That's when I checked DPs with a 25" Magnahelic on different filters on that truck. Redline/wot runs... a new paper filter was 17" wc (about the point the filter minder started moving) and K&N was 11" wc.
I got a Fleetguard catalog and I found the biggest round element that would fit and I made a round neck for it. I hooked up the Magnahelic and went for a drive. At first I thought I had the tubes reversed on the gauge and then I figured out at higher speeds, the fan makes the under-hood pressure positive and it makes for ram induction... at times, I had higher pressure on the outside of the filter than on the inside. That filter was 3" wc DP.
Later, guys were using a BHAF that was smaller than the filter I chose but theirs had a round neck molded on the ends already.
Then, I had an 03 and I moved the battery so I could use an even bigger filter (2 round elements, end to end. Those filters were 1.2" wc DP at redline/wot.
My 12 had an oily rag filter/CAI and the PO also gave me the oem paper intake. The freshly cleaned, but not yet oiled, oily rag intake had higher DP than a new 4" paper element in the oem intake. That truck was the first time I started measuring static at the turbo mouth and I also measured DPs of the filter boxes and the DPs of the tubes between the boxes and the turbo, so I could play with the oem turning vane, with different intake parts combos. I found it's an instant detriment to replace the oem tube that has a turning vane with a CAI intake tube that doesn't have the vane.
Long story short... I had 36" wc static at the turbo mouth, with the oily rag CAI intake, and I got it down to 18", with my 2 round elements and by building turning vanes in the 4" CAI tube.
All the screwing around I've done with intakes and all I've ever noticed was a little better spool up but NO power increase on my timed empty runs or on my hills, towing. That money goes a LOT farther, other places!
So in summary run the stock box with a WIX unless your going for big ponies/tq race type set ups?

I was asking about running the 5.9 drop in in the 6.7 box because I read a thread where a guy picked up 2 mpg running the thinner stock 5.9 filter VS the thicker 6.7 filter.

The bottom 1/2" of my Wix drop in in coated in oil gunk but the rest of the 3.5" are pretty clean making me think most of the filtration happens in the bottom 1/2" of the filter and a stock 5.9 Wix may offer the same filtration quality as the 6.7 but offer less resistance for better milage???
 
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