What is a Cold Air Intake system?
#11
The engine is a great big air pump. More air equals more hp, right? Now, a CIA is supposed to give more air volume along with colder air which is supposed to translate into more hp and potentially more mpg. Now, the air goes through the throttle body, right? Isn't it true that only so much air volume can got through those holes or am I way off on this? Thus, to get more air, you need a bigger throttle body, but many people on this forum have said that they are a waste of money. Thoughts??
#12
The engine is a great big air pump. More air equals more hp, right? Now, a CIA is supposed to give more air volume along with colder air which is supposed to translate into more hp and potentially more mpg. Now, the air goes through the throttle body, right? Isn't it true that only so much air volume can got through those holes or am I way off on this? Thus, to get more air, you need a bigger throttle body, but many people on this forum have said that they are a waste of money. Thoughts??
Cold air is denser and thus will move more air into the engine but in most cases this is negligible as the temp difference will not be great enough.
Mileage will only be effected if the air intake is restricted. If you flow more air into an engine you will need more fuel to burn it lowering fuel economy. This is an over simplification as many other factors will come into play to affect mileage.
TB is not a restriction on stock or mildly modified Magnums. Getting a large TB would only help if it is a restriction.
Last edited by Gerehead8; 04-06-2011 at 10:31 PM.
#13
#16
A cold air intake is designed to do 2 things: make it easier for the engine to breathe by offering is bigger piping to go through and give it a place to draw colder air.
Think of blowing through a coffee stirrer vs. through a large restaurant straw. The latter represents the CAI.
The "cold" part implies that it draws its air from a source where ambient temp is lower than that of the rest of the engine bay. Cold air is better because it is more dense, and thus, a given volume of cold air has more molecules of oxygen in it than the same given volume of hot air (example: a 1cm^3 container at 200* has less air in it than the same container at 100*).
Simple definition of temperature-dependent density: The hotter a gas is, the more energetic. A hot gas is more "spread out" than a cold one.
The only variable I have left out of this explanation is pressure.... but since a naturally aspirated engine only pulls air from the atmosphere, pressure is (nearly) always the same (16psi; or 1 bar).
Mine gave me a little better throttle response, and a hair of mid to top end power. I also recently modded my throttle body to allow my engine to better make use of the bigger piping.
Think of blowing through a coffee stirrer vs. through a large restaurant straw. The latter represents the CAI.
The "cold" part implies that it draws its air from a source where ambient temp is lower than that of the rest of the engine bay. Cold air is better because it is more dense, and thus, a given volume of cold air has more molecules of oxygen in it than the same given volume of hot air (example: a 1cm^3 container at 200* has less air in it than the same container at 100*).
Simple definition of temperature-dependent density: The hotter a gas is, the more energetic. A hot gas is more "spread out" than a cold one.
The only variable I have left out of this explanation is pressure.... but since a naturally aspirated engine only pulls air from the atmosphere, pressure is (nearly) always the same (16psi; or 1 bar).
Mine gave me a little better throttle response, and a hair of mid to top end power. I also recently modded my throttle body to allow my engine to better make use of the bigger piping.
#17
The reason the TB is not really a restrictive point on our engines is because we utilize plenum design intakes. This means that the TB only needs to flow enough air to keep the plenum supplied with air, not necessarily enough to fill each cylinder to max on each intake stroke. So as long as your TB flows enough air (along with the other sources of air it is getting, like vacuum and crankcase blowback) to keep the plenum full, then anything bigger then that doesn't help much because you just can't flow more air into the plenum space then it can hold without compression (which you need a turbo or supercharger to achieve). So bored out TB's (or smoothed out TB's) are a good mod to a point. They make it easier for air to enter the plenum, (which is good, and makes a noticeable difference). But after that, there isn't much else they can accomplish.
Last edited by Silver_Dodge; 04-06-2011 at 11:16 PM.
#18
This laminar flow is broken up when it hits the TB, but up to that point the CAI has made it easier to draw in air; and thus, has made the engine more efficient.
#19