OK so the warm engine air is going to have a hard time moving to in front of the radiator, while driving and also when sitting at a traffic light. When driving the air coming in through the radiator is blowing in the direction of the firewall. so any hot air in the engine bay is not going to try and make a mad dash through the crowd to get in front of the radiator. and when the fan is running the same thing happens....
This movement also causes the air from the air cleaner location to get pulled into the engine bay this causes a low pressure condition. Air is going to have a really hard time getting to that spot from the engine bay because it is being told to go in the opposite direction either by the movement of the car or the fan. And what adds to that is the removal f air that takes place due to the intake sucking it in. If you open the solstice hood and walk in front of the car then look straight down between the headlight and the bumper cover that is where the air comes up from. The air down there has not been heated at all this is the air that take care of that low pressure condition
You can test this by running your car for IDK... 1 or 2 hours if you like. Then stop the car and shut it off, get out and open the hood. Stand in front of the car and stick you hand under the edge of the hood and touch the front of the air cleaner box.
Do the same thing and let the car sit there idling for an hour. You need to have the hood closed during the entire hour. after an hour is up shut the car off open the hood and check. I am pretty confident that the front of the air cleaner bx is not going to be all that warm if at all.
FYI technically speaking only an intake that has a pipe made from plastic can be classified as a cold air intake. Aluminum is a fantastic conductor of what?? Heat. When there is moving air across the aluminum what happens?? It transfers that heat into the air that is moving across it. The velocity of the air that is moving inside the intake is going to be faster then outside, so an aluminum pipe is going to transfer engine bay heat right into the intake air. Not really cold air after all is it?
When they came up with these devices is when they were using doughnut style air cleaners that sat on top of the engine. so yes. an aluminum pipe with an air cleaner at the end of the pipe and that air cleaner was in a fender... or some where other then the top of the engine is always going to function better then the doughnut on top of the engine.. Now before someone makes a statement about an old school hood scoop, that kind of a design is not included in this example. I am talking about a plain Jane up to the mid 1970's type of air cleaner that was found on top of the engine and that air cleaner sat right on top of the carburetor. my point being the air going in at that spot is going to be just about the hottest that is inside that engine bay. So doesn't matter what the pipe was made of so long as it got air from the edges of the engine bay it was always going to be colder. Most cars made currently will pull air that is not engine bay air. Now there could be a power improvement because of a restriction in the stock intake system, any improvement seen when installing a CAI on a modern vehicle is not because of the temperature of the air.
If you want the intake to make more noise, and keep the air going into the engine cold... get out the hacksaw and cut the stock air cleaner box off as close as you can get to it. Go and buy a cone style air cleaner for 40-60 bucks that has the same size opening as the diameter of the pipe where you cut the stock box off clamp it on. and you now have the best CAI that money can buy.
