Intake system help
Post Fiend
Joined: Feb 2007
Posts: 14,541
Likes: 2
From: Dallas-Ft. Worth
From what I've read, that's a great intake...
Lead Driver
Joined: Dec 2006
Posts: 7,093
Likes: 147
From: San Diego, CA
Anything that replaces the stock air box is an improvement, since it doesn't seal well (even with an aftermarket filter in there).
Sure the 6637 mod sucks in engine compartment air, but the zoodad mod helps with that.
I would love to write checks all day and order everything I wanted for my rig, but unfortunately my bank account isn't bottomless (more like the shallow end of the kiddie pool these days). I can either spend $200-$500 for the AIS, aFe, Volant or S&B and get an intake, or I can spend $50, get a 6637 and do the zoodad for free. Hhhmmm...which do you think my wife gave the green light for...? I'll take anything I can get over the stock box! Plus that leaves me a little extra to put aside for those gages I've been saving up for...
Sure the 6637 mod sucks in engine compartment air, but the zoodad mod helps with that.
I would love to write checks all day and order everything I wanted for my rig, but unfortunately my bank account isn't bottomless (more like the shallow end of the kiddie pool these days). I can either spend $200-$500 for the AIS, aFe, Volant or S&B and get an intake, or I can spend $50, get a 6637 and do the zoodad for free. Hhhmmm...which do you think my wife gave the green light for...? I'll take anything I can get over the stock box! Plus that leaves me a little extra to put aside for those gages I've been saving up for...
Hotshot
Joined: Jul 2003
Posts: 12,177
Likes: 40
From: Newport, WA
If you're worried about sucking in warm air from under the hood, build a cold air box for your 6637 as many here have done.
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Postmaster
Joined: Jun 2006
Posts: 2,647
Likes: 0
From: Fulltime RVer
I'd sure like to hear your definition for "the best" and a summary of you research that indicates the aFe is better than for example the S&B unit.
Postmaster
Joined: Jun 2006
Posts: 2,647
Likes: 0
From: Fulltime RVer
...If you assume that there's 5.28 ft^3 of free air space available in a 7.3L engine compartment from the hood (closed of course) down to the bottom of the engine then this 5.28 ft^3 engine compartment air space implies that an "open element" AF which is sucking in a 528 CFM airflow to supply the engine sucks all of the available air out of the engine compartment 100 times each minute! Where does all of the needed replacement air come from?
It comes from the ambient air but thanks to the Ford design 100% of the ambient replacement air is forced to flow through a 140 F A/C condenser, then if you're at a sustained 18 psi boost it's forced to flow through a 160 F IC, and finally it's forced flow through a 190 F radiator and then it picks up even more heat from the exhaust manifolds etc.. and then it flows directly into your "open element" AF!
And yet people continue to claim that the air flowing into their "open element" AF is only 2 F or 20 F or whatever unbelievable (for me anyway) low number of "F" hotter than the ambient air is!
Now consider an alternative. if you're going 60 MPH=5,280 ft/min a "cold air intake" only needs to have a 0.1 ft^2 (3.8"x3.8") opening in order to supply an AF with a 528 CFM flow of "outside RAM ambient air" which no matter how you want to cut it is much cooler than the ambient air that's forced to flow through the A/C condenser, the IC, and the radiator!
In addition to being much cooler the "outside RAM ambient air" due to its RAM air effect also supplies the "cold air box" with "pressurized" air which reduces the restriction of the "cold air element" by 2" H2O.
This means there's two different ways by which a "cold air intake" reduces the workload on your turbo relative to the workload that's required for an "open element" AF... 1) the cooler air increases the air density at the compressor wheel and 2) the higher pressure air increases the air density at the compressor wheel.
Since MAF={(AD)(CFM)} lb/min an increased AD=Air Density lb/ft^3 means that it takes less CFM to provide a given MAF to the engine and less CFM means the compressor wheel rpm is lower for the same MAF. Conversely an increased AD means that more MAF can be provided at a given CFM...
It comes from the ambient air but thanks to the Ford design 100% of the ambient replacement air is forced to flow through a 140 F A/C condenser, then if you're at a sustained 18 psi boost it's forced to flow through a 160 F IC, and finally it's forced flow through a 190 F radiator and then it picks up even more heat from the exhaust manifolds etc.. and then it flows directly into your "open element" AF!
And yet people continue to claim that the air flowing into their "open element" AF is only 2 F or 20 F or whatever unbelievable (for me anyway) low number of "F" hotter than the ambient air is!
Now consider an alternative. if you're going 60 MPH=5,280 ft/min a "cold air intake" only needs to have a 0.1 ft^2 (3.8"x3.8") opening in order to supply an AF with a 528 CFM flow of "outside RAM ambient air" which no matter how you want to cut it is much cooler than the ambient air that's forced to flow through the A/C condenser, the IC, and the radiator!
In addition to being much cooler the "outside RAM ambient air" due to its RAM air effect also supplies the "cold air box" with "pressurized" air which reduces the restriction of the "cold air element" by 2" H2O.
This means there's two different ways by which a "cold air intake" reduces the workload on your turbo relative to the workload that's required for an "open element" AF... 1) the cooler air increases the air density at the compressor wheel and 2) the higher pressure air increases the air density at the compressor wheel.
Since MAF={(AD)(CFM)} lb/min an increased AD=Air Density lb/ft^3 means that it takes less CFM to provide a given MAF to the engine and less CFM means the compressor wheel rpm is lower for the same MAF. Conversely an increased AD means that more MAF can be provided at a given CFM...
Postmaster
Joined: Jan 2009
Posts: 2,544
Likes: 4
From: Suffolk, VA
Instead of laying a temp sensor or thermometer near the filter and out in the open under the hood, has anyone probed the air intake tube between the filter and the turbo inlet? I'd love to see those measurements between a filter on a stick and a factory or AIS intake; or even an enclosed filter on a stick for that matter.
Damn, I might just have to see if I can borrow or steal a temp probe and do it myself 'cause I'm curious. Not sure what to do with the hole in the intake tube afterward though.
Damn, I might just have to see if I can borrow or steal a temp probe and do it myself 'cause I'm curious. Not sure what to do with the hole in the intake tube afterward though.
Hotshot
Joined: Jul 2003
Posts: 12,177
Likes: 40
From: Newport, WA
Instead of laying a temp sensor or thermometer near the filter and out in the open under the hood, has anyone probed the air intake tube between the filter and the turbo inlet? I'd love to see those measurements between a filter on a stick and a factory or AIS intake; or even an enclosed filter on a stick for that matter.
Damn, I might just have to see if I can borrow or steal a temp probe and do it myself 'cause I'm curious. Not sure what to do with the hole in the intake tube afterward though.
Damn, I might just have to see if I can borrow or steal a temp probe and do it myself 'cause I'm curious. Not sure what to do with the hole in the intake tube afterward though.
