Better flowing intake for 5.7 w/Ecodiesel lower airbox

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Chris Kyle

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Has anyone who has done this modification noticed improvements in fuel mileage? I wonder also if my exhaust would sound a little throatier under throttle.
I haven't noticed any fuel economy improvement around town or any louder engine/exhaust noise. I have yet to get the truck out on the interstate, though.
 

kurek

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I imagine it would be the same reason that K&N and other free-flowing air filters claim more power and better mpg.

I'm guessing those product manufacturers have an incentive to say whatever they can get away with to sell merchandise.

There's probably some truth to the idea that this specific modification can produce more power; like just doing napkin math if you achieve 97kpa (14.06psi) at WOT outside the throttle body with the OE intake assembly and 100kpa (14.50 under the same conditions with the airbox/filter/horn being discussed here that's pretty similar in effect to having a 0.44psi boost which might nudge your 395hp engine just barely over 400hp peak.

But that's just the difference you measure at WOT, it might be like 99.97kpa vs. 100kpa at 1/8th throttle and the fuel trim will just adjust to compensate since it can't really differentiate between the restriction presented by the throttle blade and any restrictions occurring upstream of it. If you find yourself using 0.03% less throttle to achieve a given target acceleration (using the same total volume of air and fuel) and the engine calculates your shift point 0.03% earlier since it's measuring 0.03% less commanded throttle from your pedal, would you notice that on your fuel receipts? I wouldn't.

Not saying I'd mind a plausible five peak horsepower if it's there and almost certainly without any drawbacks or gotcha's but there's just no mechanism by which this would improve fuel mileage.
 

bfill_rebel

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Installed the 6.4/EcoD box this evening - excited to see if any change tomorrow. If not, I've wasted $70 on worse things - so little downside.

Thoughts after the first month??


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emjohn4

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Thoughts after the first month??


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Good question! Gas mileage unchanged; intake noise maybe slightly louder, but no perceivable difference in power.

Bottom line: No difference observed. Mentally, I am happy I have it just because it should flow more, but functionally, no difference at all.
 

46RamMan

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I see that if nothing else the deeper pleats on the new filter will last longer between changes and the motor will breath earier.. a win win I think..:D:D
 

VaDimZH

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The link posted by OP is pretty expensive for shipping!
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DO NOT PAY FOR SHIPPING $30 (OP link) !!! Its crazy expensive!

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VaDimZH

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Good question! Gas mileage unchanged; intake noise maybe slightly louder, but no perceivable difference in power.

Bottom line: No difference observed. Mentally, I am happy I have it just because it should flow more, but functionally, no difference at all.

I was going to buy it but now I don't know...
 
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VaDimZH

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The filters are the same outer dimensions so you can swap back and forth.
The EcoDiesel airfilter is the same part# used in the 6.4l Hemi, the thicker airfilter will flow more air and hold more dirt before it's clogged up.
Why 5.7L need thicker air filter.

As I understand the EcoDiesel/ 6.4 needs it because it's a bigger displacement motor.

?
 
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VaDimZH

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I’ve ordered the lower air box, inlet and the OEM eco diesel filter. A little better breathing combined with factory water protection and good filtering sounds like a win/win.
Isn't a stock breathing and filtering are good enough for 5.7L?
 
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Joes1500

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Why 5.7L need thicker air filter.

As I understand the EcoDiesel/ 6.4 needs it because it's a bigger displacement motor.

?



The eco diesel is a 3.0 liter. Almost half the size of a 5.7.

More/thinker pleats means more surface area that has to get dirty before restriction happens.
 

VaDimZH

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The eco diesel is a 3.0 liter. Almost half the size of a 5.7.

More/thinker pleats means more surface area that has to get dirty before restriction happens.
So,why Ecodiesl 3.0L needs more thicker pleats/more surface area than 5.7L HEMI,with less surface/thicker pleats?
 

crash68

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So,why Ecodiesl 3.0L needs more thicker pleats/more surface area than 5.7L HEMI,with less surface/thicker pleats?
As @Joes1500 pointed out, being a turbo diesel it uses more air. Depending on the load mine will usually build about 15-18 psi of boost at about 2100 rpms and I've seen it peak at upwards of 25 psi
 

VaDimZH

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This means that there is no need for a more thicker pleats/more surface area filter for 5.7L,because 5.7L is not a turbo charged diesel and not a 6.4L bigger displacement motor.
 

kurek

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I think the real mystery is why they even needed to make different parts for the different vehicles... clearly they all fit the same place since this swap is possible, and there can't be any harm in putting a "too big" air filter designed for a 6.4 on a 5.7, the throttle body regulates air intake so there's just no way it could possibly suffer any problems from having "too much" clean filtered air available...

I could imagine the ecodiesel and the V8's having different airboxes if the box itself is meant to act as a resonator to reduce intake noise since 6cyl engines sound inherently different from 8cyl engines no matter what their displacement & geometry looks like. But the V8's could just use the same box and avoid needing to stock two different parts both in manufacturing and in repair/maintenance inventory. Maybe something I don't understand about supply chain, I know they make enough of both trucks to justify each part existing but if you have an opportunity to streamline shouldn't you take it?
 

Joes1500

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This means that there is no need for a more thicker pleats/more surface area filter for 5.7L,because 5.7L is not a turbo charged diesel and not a 6.4L bigger displacement motor.



There is never really a need to do any modifications to a vehicle. If you need a vehicle for a specific task then buy one that suits those needs.

But the bigger filter will give you a longer service life.
 

ckleinfeld

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So,why Ecodiesl 3.0L needs more thicker pleats/more surface area than 5.7L HEMI,with less surface/thicker pleats?
The Eco does not use more air, all things being equal it would need to produce ~28psi boost to even use the same air flow as the 5.7.

Turbochargers are sensitive to intake depression (pressure drop) for a couple reasons. First, compressor efficiency. Intake temps would increase with a more restrictive air intake system, hurting performance. Secondly, oil usage. As the filter loads up, and depression increases, the turbo will start to pass oil across the compressor side seal and the engine will see increased oil consumption. The is the #1 reason turbos are changed for suspected failure. Increased filter capacity reduces the risk FCA would face with folks trying to claim warranty for a "faulty" turbo when it's nothing more than a dirty air filter.

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