Stock Air Box Mod

19LaramieRam

Active Member
Messages
27
Reaction score
30
Points
13
I was searching the inter web and came across a mod for the stock air box the 4th gen guys are using.

It involves adding a 3” hose to the bottom of the air box to increase the available volume of air. The other end of the hose is routed somewhere to the front of the vehicle and down low to provide cool air. Has anyone tried/thought about doing this?

it looks like a cheap mod and the 4th gen trucks were having great results. The stock air box seems good but is limited by air supply. I will link the article when I find it again...
 

7amada

Active Member
Messages
108
Reaction score
17
Points
18
Following...

my only concern with low intakes is the risk of sucking up water if you live someplace that floods (i live in houston)
 

19LaramieRam

Active Member
Messages
27
Reaction score
30
Points
13
 

19LaramieRam

Active Member
Messages
27
Reaction score
30
Points
13
Following...

my only concern with low intakes is the risk of sucking up water if you live someplace that floods (i live in houston)
Yes I thought that also, but with the wheel well opening remaining, the engine would never have enough suction to draw up any amount of water and the pressure differential would then favor the wheel well as the primary air source.
I also might try this in the spring, if it doesn’t workout or I don’t like it there is always the option to cap the opening and return to stock conditions.
 
Last edited:

Damion

Active Member
Messages
172
Reaction score
100
Points
43
Another popular air box mod for the 4th gens is to use the bottom airbox from an eco diesel , the fresh air inlet on it is considerably bigger than the Hemi one, uses all factory parts and unless you knew it was done you'd never know by looking at it. Not sure if the 5th gens can be done the same way though
 

DesertRebel

5thGenRams Supporter
Site Supporter
Messages
175
Reaction score
108
Points
43
Location
AZ
My only concern would be how fluid dynamics come into play... When altering airflow, sometimes you don't get the intended consequences... However it's possible the added airflow would introduce the venturi effect - which "could," be beneficial.

I'm not an expert in fluid dynamics - but did a bunch of beta testing with a previous boring engineer for intake and exhaust mods on a different vehicle - and leaned that fluid dynamics often will have negative effects on things that seems like they'd work.
 

19LaramieRam

Active Member
Messages
27
Reaction score
30
Points
13
My only concern would be how fluid dynamics come into play... When altering airflow, sometimes you don't get the intended consequences... However it's possible the added airflow would introduce the venturi effect - which "could," be beneficial.

I'm not an expert in fluid dynamics - but did a bunch of beta testing with a previous boring engineer for intake and exhaust mods on a different vehicle - and leaned that fluid dynamics often will have negative effects on things that seems like they'd work.
I’m not sure what fluid dynamic effects would come into play. The losses associated with the pipe wall would be minimal/negligible for such a short run of pipe in this application. And air will always move naturally from an area of high pressure to low pressure.

I think the real benefit to this mod would be the increased available volume of air to the air filter housing. We are not modifying the tube to the throttle body or the filter itself or trying to get RAM air, rather provide a “larger” available volume of air to the housing, reducing lag time and improving throttle response.

In the thread I linked, one member did his own testing by adding a temperature transmitter to the air tube and tracking the temps during normal driving conditions and found he had cooler air while moving, the air temp climbing back to stock numbers while stopped in traffic. That itself sounds like a win to me and a true cooler air mod.

Sorry for the long response, that got my engineering mind thinking... (I do not miss fluid dynamics, btw) I plan to do this mod when the weather turns nicer, and will report back on any findings. All thoughts on this are welcome!
 

Goatmann

Ram Guru
Messages
515
Reaction score
326
Points
63
Location
Florida
i do not understand this, need some help.

installed is an airbox designed for the engine. air gets sucked into the motor throught the throttle body which is some diameter. how is increasing the air box air feed going to benefit anything?

one can put a 13 gallon trash can on the end of the intake but only use what the TB CFM's can pull.

i am not a dumb man, just asking.
 

19LaramieRam

Active Member
Messages
27
Reaction score
30
Points
13
i do not understand this, need some help.

installed is an airbox designed for the engine. air gets sucked into the motor throught the throttle body which is some diameter. how is increasing the air box air feed going to benefit anything?

one can put a 13 gallon trash can on the end of the intake but only use what the TB CFM's can pull.

i am not a dumb man, just asking.
I am running on the assumption that the existing opening is a restriction, i.e. the throttle body can open and pull more air than the current opening can provide in ‘X’ amount of time. If my assumption is correct, more available inlet volume should increase throttle response and cooler air will be delivered.
It is possible there is nothing to be gained but for under $20 it’s worth a shot! Also with that logic CAI do nothing..
 
Last edited:

jabara572

Active Member
Messages
119
Reaction score
49
Points
28
Location
Atlanta, GA
Not needed on a 5th gen, we already have a cold air tube/port that pulls air from the grill area. I can almost guarantee that the stock airbox on the 5.7 HEMI is NOT a choke point on a stock or lightly modified engine, its huge and very well designed. Thought i read somewhere it was mean to support about 500hp.

Getting rid of the accordion tube with a smooth one may yield some incredibly small benefit, or replacing the TB with a larger one.... then you can talk about opening up the ducting, but stock TB, stock motor...forget it, it will do absolutely nothing.
 

19LaramieRam

Active Member
Messages
27
Reaction score
30
Points
13
Not needed on a 5th gen, we already have a cold air tube/port that pulls air from the grill area. I can almost guarantee that the stock airbox on the 5.7 HEMI is NOT a choke point on a stock or lightly modified engine, its huge and very well designed. Thought i read somewhere it was mean to support about 500hp.

Getting rid of the accordion tube with a smooth one may yield some incredibly small benefit, or replacing the TB with a larger one.... then you can talk about opening up the ducting, but stock TB, stock motor...forget it, it will do absolutely nothing.
That is some good information! I will be honest I have not taken the time to look in the engine bay much since I got the truck. Since the seem to have redesigned the air box some, would you say that makes aftermarket CAI novelty items unless you have heavily modified? I agree the accordion tube probably does not result in any significant pressure drop to justify replacing it!
 

jabara572

Active Member
Messages
119
Reaction score
49
Points
28
Location
Atlanta, GA
That is some good information! I will be honest I have not taken the time to look in the engine bay much since I got the truck. Since the seem to have redesigned the air box some, would you say that makes aftermarket CAI novelty items unless you have heavily modified? I agree the accordion tube probably does not result in any significant pressure drop to justify replacing it!

That is pretty much the consensus right now is any aftermarket CAI just sounds cool, of course the companies claim all this horsepower but I've yet to see an independent Dyno of one back to back showing a gain. I'm sure they pick up some small hp but is 2hp worth $300 to you? It isn't to me...

You can look into a vararam or RAM AIR system which may add some hp on the highway but again.... Waiting on some proof
 

Nails

Ram Guru
Messages
952
Reaction score
472
Points
63
Location
San Antonio
I’ve looked into this mod the 4th gen peeps do. The main and only problem is the low part of the box doesn’t have enough space to support that mod.
And as stated, this factory set up would support much higher air demands then stock and probably FBO. Say till cammed, even then I’d like to see the evidence. Which is probably main/first restriction with exhaust manifolds and y pipe second. I’ve seen SC 5th gens still using stock box.
 

Bubba33

Active Member
Messages
82
Reaction score
56
Points
18
Stock air box is good. Aftermarket are just a sound box, that makes it sound like it's going faster. Like flipping the lid on a Qjet .
 

Users Who Are Viewing This Thread (Users: 0, Guests: 1)

Site Vendors

Top