Editing Cold air intakes

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When I think of Cold Air Intakes, the first car that I think of is the 1964 Ford Fairlane THUNDERBOLT. Dearborn Steel Tubing, known as DST purpose built these cars for drag racing for Ford. The engines that they were using were 425 HP 427 Cu. In. How do you feed cold air to a engine of this size? BIG PIPES! How big? About 6 inch diameter. When you need to get cold air from the frontal area to the gigantic carburetor intake you take the most direct route. Kick out the inner headlights (who needs four headlights on a drag strip), add some grills to keep out large debris, run the expansion pipe up to the aluminum intake box and you have it. Check out the pictures on how they did it back in 1964.

[[Image:Headlight_intake_grill.jpg]]


[[Image:Side_view_of_cold_air_intakes.jpg]]


[[Image:Dual_intake_pipes.jpg]]

Of course, other people have their own views on what cold air intakes should be, and they're entitled to them. '''BIG IS BETTER'''

This is really quite simple; a great project for the budding automotive enthusiast.

First you need to know the diameter of the stock intake tubing, and where you want your filter- usually a cone type reusable gauze filter.


Then you look under the hood... 
It probably looks something like this
[[Image:http://www.ayocee.com/cmine/albums/oilchhowtwo/normal_Oil%20Change%20Howto%20002.jpg]]
It's a stock 1.9L Saturn engine, of the SOHC (single over head cam) variety.  Notice the stock intake tubing on the right side of the picture.  It's designed to be cheap to make, reduce noise, and be easy for the guy on the production line to install, with minimal care for performance, especially in a non-sports car (think Corvette or Porsche).

Take the measurements of the throttle body outside diameter (OD) and head to the parts store.  Since the throttle body is horizontal (if it were a carburetor, it'd be a sidedraft), you'll need a 90-degree elbow to follow the general path of the stock stuff that has .  Make sure it's heat and oil resistant, and then get some tubing with the same inside diameter (ID) as the throttle body.  The intake tubing (some people use pvc pipe, I prefer metal such as aluminum) needs to have the OD the same as the ID of the 90* elbow.  Using various parts, being creative and inventive, piece these together ensuring you have enough room for the air filter at the end!

Lastly, make sure you have provisions for crankcase lines (or a crankcase breather filter) and have enough hose clamps for all joints in the system.  The picture below is of a Saturn 1.9L engine (the twin cam variety) with a shortram intake.  It's not a true cold air intake since the air going into the engine is from the engine compartment.
[[Image:http://hotrodders.com/gallery/data/3121/IM000157.JPG]]

Normally a shortram/warm air intake is a better idea if your car sees snow and other wet, inclement weather.  A CAI is better suited for track use or for a car which rarely (if ever) sees bad weather.  If your car pulls water up in the intake then you'll hydrolock it and if you're lucky you can pull the spark plugs out, crank the engine a few times, reinstall plugs, and be on your way.  Lots of times you'll ruin the internals of the engine since water will not compress.  The engine parts will bend before water will compress! In some instances you can use a bypass that eliminates the threat of sucking up and water.


Bigger is not always better?  Your engine will only breathe in what it can, unless it is forced in, turbo, blower, etc.  Ramming it in does not produce more power, it still will only breathe what it needs, unless you are cruising at 200+ MPH...

Cold air intakes are used in applications where the owner/operator feels that the vehicle will produce more power with an outside air charge.  Huge misconception, cold air intakes do not produce more power, at least not power that you will feel in the seat of your pants.  Most vehicles built today are set up pulling air in from the outside, not from the engine compartment.  If you notice that the air filter housing/box is located on one side or the other of the engine compartment, and has ducting that goes through the inner fender.  Thus, this is pulling in outside air.  It seems that most aftermarket cold air intake kits include the ducting that is smooth, not ribbed or corrugated, this allows for less disruption of the airflow, which in most cases is a heck of a lot more important than the incoming air temperature.  High flow air filters in stock intake boxes/housings with smooth ducts works just as well as the high dollar kits that most people invest their money in.  Another look, most newer vehicle's air filtration systems flow just as well as the aftermarket competitors, it has been proven.  And, some just like the look???

Then there's the other line of thinking based on physics which states that for each 10* drop in air temperature going into the motor, power will pick up by 1%. This is because when the air is colder, it is more dense and therefore contains more oxygen. Of course, a tuner would have to compensate for more oxygen by jetting fatter to get the air/fuel mixture back to correct. I don't know much about EFI, being a carburetor guy, but I would think that a computer-controlled system would sense more oxygen and automatically richen the mixture. It just makes sense that if you are pulling in engine bay air which was just pulled through the radiator at 200* and you install a system to pull in (for instance) 100* air from the outside of the car, you have a 100* drop in air temperature which should equate to a 10% increase in power. On a 400 hp motor, this would work out to 40 hp. I would think any tuner in his right mind would jump at the chance to pick up a power increase like that just for running some tubing to the outside. I see these Honda guys all the time who install an aftermarket pipe and then terminate the air filter right behind the radiator in the engine bay. This is obviously monkey-see, monkey-do without any idea of what they're doing. Just money thrown away in my opinion. If they would simply extend the tubing to the outside of the car, they could take advantage of the colder ambient air and make more power.

[[Category:Engine]]