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dssilvestri 03-19-2012 11:54 AM

Hemi Factory Ram Air ?
Did anyone notice the vent from behind the grill leading to the airbox on their hemi ? what exactly is this ?

JeepCoop 03-19-2012 12:02 PM

It acts like ram air kinda. Just allows fresh air to flow to the stock air box and into the motor

dr.lee.baugh 03-19-2012 12:46 PM

Re: Hemi Factory Ram Air ?
I think they use this set-up for a couple of reasons.

1) As mentioned above, it allows a passage for fresh (often cooler) air from outside of the engine compartment to be used in combustion.

2) It lessens the likelihood of water making it's way into the system by preventing a direct flow from the outside to the air filter.

Walt 03-23-2012 05:44 PM

Re: Hemi Factory Ram Air ?

Originally Posted by dssilvestri (Post 596421)
Did anyone notice the vent from behind the grill leading to the airbox on their hemi ? what exactly is this ?

It's the combustion air intake. As stated previously, because it takes air in front of the radiator support, the air temperature tends to be somewhat cooler than if it were pulled from the engine compartment (like older cars).
My IAT tends to run in the vicinity of 10-20F above ambient, depending on ambient temperature, vehicle speed, and whether or not MDS is active.
The denser air contains more oxygen per unit volume, and thus, the engine can can produce more power per ignition cycle. PCM uses IAT and MAP sensors to determine incoming air density and then calculate appropriate fuel charge delivered by the fuel injectors.
Jeep did it right with a compromise design to get coolest air, while still protecting against unwanted debris intrusion into the air filter cavity and a high location that minimizes the chance of accidental water ingestion. Since it is sized to flow enough air to reach red-line full power (maximum air flow), it will have more-than sufficient air flow for normal driving (1,500-3,000 rpm) conditions.
Factory has already given you a CAI! :D

jeep5.7 03-24-2012 08:57 AM

Re: Hemi Factory Ram Air ?
i think its a great design

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