DIY: Airbox mod - Cool Air Injector (anti-56k)
#16
Originally Posted by Skaterbasist
CAI don't do squat. This is just a way of redirecting cold air without having to go with a long-ram intake setup.
IMO, its a great approach.
.
IMO, its a great approach.
.
#17
he is replacing a sealed resonator that provides NO air with this duct, which provides some cold air. the intake still gets the majority of its air from up top, but since it now has a colder source for a portion of the air, and since warm air rises, the warmer air will be released through the top openings and this will replace some of it with lower temp air. it's a great idea
#18
Originally Posted by manbeer
he is replacing a sealed resonator that provides NO air with this duct, which provides some cold air. the intake still gets the majority of its air from up top, but since it now has a colder source for a portion of the air, and since warm air rises, the warmer air will be released through the top openings and this will replace some of it with lower temp air. it's a great idea
So, even though it seems like stuffing a tube (whether long ram or a mod like this) is drawing in cold air, it's actually drawing in much hotter air than is being drawn in from the upper intake (through the grille). Which is why a short ram intake being used with the OEM snorkel is actually more of a "cold air" intake than a long ram intake shoved down low (typically called "CAI").
#20
.
During the day, when the ground is heated by the sun, small scale turbulence transfers heat from the ground to the air that is in contact with it. This warmed air then rises because its density is less, and is replaced by cooler air from above it. Wind turbulence enhances this effect so that surface heat is readily transferred through the air mass. At night a different situation prevails. Ground no longer heated by the sun cools by losing radiant heat to the upper atmosphere and to space, especially if the sky is cloudless. The air, particularly layers near the ground, becomes cold, even though turbulence is now transferring heat from above down to the cooling surface.
Cold air is denser than warm air, so the cold air near the ground sinks to the lowest level it can find, while the warm air remains above it. The wind turbulence now has great difficulty in stirring up the heavier cold air layers near the ground and replacing them with eddies of warm air from higher up. So the cold air becomes even colder, and the wind dies away. This reversal of the normal daytime decrease of temperature with height is called a temperature inversion.
http://www.bom.gov.au/info/ftweather/page_3.shtml
the air may be a few degrees warmer in the daytime with the sun beating down on the ground, but still cooler than engine bay air, and less restrictive than the stock setup, and at night, the cooler air is falling to ground level
During the day, when the ground is heated by the sun, small scale turbulence transfers heat from the ground to the air that is in contact with it. This warmed air then rises because its density is less, and is replaced by cooler air from above it. Wind turbulence enhances this effect so that surface heat is readily transferred through the air mass. At night a different situation prevails. Ground no longer heated by the sun cools by losing radiant heat to the upper atmosphere and to space, especially if the sky is cloudless. The air, particularly layers near the ground, becomes cold, even though turbulence is now transferring heat from above down to the cooling surface.
Cold air is denser than warm air, so the cold air near the ground sinks to the lowest level it can find, while the warm air remains above it. The wind turbulence now has great difficulty in stirring up the heavier cold air layers near the ground and replacing them with eddies of warm air from higher up. So the cold air becomes even colder, and the wind dies away. This reversal of the normal daytime decrease of temperature with height is called a temperature inversion.
http://www.bom.gov.au/info/ftweather/page_3.shtml
the air may be a few degrees warmer in the daytime with the sun beating down on the ground, but still cooler than engine bay air, and less restrictive than the stock setup, and at night, the cooler air is falling to ground level
Last edited by UR2EZ; 10-25-2008 at 06:50 PM.
#21
Originally Posted by OCG35
air temps 1-2 feet above the ground is actually hotter than it is from 2 feet and above (as measured by DaveO and myself a couple years ago) - black asphalt absorbs heat and continuously is radiating hotter than the ambient air up higher. This isn’t to say its hotter than what the OEM opening is sucking up (I'm not sure how hot it gets down there - but I'm pretty sure its cooler than upper engine compartment).
So, even though it seems like stuffing a tube (whether long ram or a mod like this) is drawing in cold air, it's actually drawing in much hotter air than is being drawn in from the upper intake (through the grille). Which is why a short ram intake being used with the OEM snorkel is actually more of a "cold air" intake than a long ram intake shoved down low (typically called "CAI").
So, even though it seems like stuffing a tube (whether long ram or a mod like this) is drawing in cold air, it's actually drawing in much hotter air than is being drawn in from the upper intake (through the grille). Which is why a short ram intake being used with the OEM snorkel is actually more of a "cold air" intake than a long ram intake shoved down low (typically called "CAI").
#22
Asphalt ground temps are as much as 20 degrees hotter bellow 18" or so than 36" or so - on a normal sunny day... engine heat is much hotter in the upper part of the bay than down low when this air box hole is... so comparing engine heat soak from down here isn’t relative.
As I stated previously, I cant say whether or not that heat at the point of the OEM hole is hotter or cooler than ground air, I haven’t measured it... but drawing air from just above the ground is definitely not "cold air".
As I stated previously, I cant say whether or not that heat at the point of the OEM hole is hotter or cooler than ground air, I haven’t measured it... but drawing air from just above the ground is definitely not "cold air".
#24
#26
#28