If CAIs are so great, how come....
 

How come car manufacturers don't put them in their vehicles(stock)? does it cause long term damages to the engine? is it because of the noise they make?

probably cause theyre louder

I guess

all manufacturers put restrictive intakes on them even on sports cars...usually to reduce noise....however be careful using the term CAI or Cold air intake...a lot of stock systems are designed to pull air from outside the engine compartment..i saw the engine bay of a 91 MX-6 and a 2001 F-150 and they both pull air from the fender or wheel well..the main purpose of aftermarket intakes is to use a Cone filter which uses a higher flowing filter and have high surface area,thus they flow more air...plus most aftermarket intakes are dangerous because they pull air close to the ground and risk pulling in water...for most manufacturers reliability is higher on the list than performance

for one its louder and they try to get the car as quite as possible, also, the more restrictive they make a car, the less power it puts out and so they can sell the car for less, and most people don't care about how fast the car goes, so they perfer a quiter car, also in some states, open filter setups(CAI) do not pass inspection, but almost everyone will pass it though.

I'm just not following that logic. If there was a cheap way that an auto manufacturer can add a few horsepower you can bet that they will do it. In the competitive world of auto sales, any advantage can translate into greater sales.

So why don't they make CAI standard? Probably becase the noise and the potential possibility of sucking water into the engine. Or maybe it's because they fear that you'd have to change the filter more often because it's out in the open and exposed to dust, oil and whatever else that's in the engine bay.

well its cheaper to put on rubber tubing into a box that uses paper filters, ford uses k&n now but its still cheaper than using mandrell bend tubing, also alot easier to manufactor. allmost every car has a CAI setup, its just very restrivtive, esp with a crapper paper filter. The tubings bends a flexs everytime you rev the motor, causing turbulance not allowing much air in. Most of it is a cost cutting thing

That's what I thought, along with the noise thing.

There are many considerations, as a matter of fact if a manufacturer like Mazda wanted mandrel bent tubing they could keep the cost so low there would be no no competition from the aftermarket. They (Mazda) design and build cars that they can produce in the hundreds of thousands that will perform in a wide range of environmental circumstances fairly flawlessly. Bottom line... they choose as best a compromise as possible. Anyone who thinks it's cheaper to produce about 15 seperate plastic pieces that need to be screwed together and then assembled into a car engine bay versus seven or so pieces like an aftermarket setup has no clue.

plastic is cheaper than metal along with the paper filter

And you know this how? Do you have any numbers to back this up??

If it is true, then why can't Mazda just design a plastic tube instead of a metal tube? Is there some reason that a CAI has to be made of metal tubing? I don't think it's a cost issue for Mazda or any other car manufacturer to add a CAI into a car.

If you consider how cheaply Mazda could buy tubing in massive lengths and pay a reletively small number of people to bend and cut it compared to the cost of injection molding more (by sheer number) pieces that need more handling, I would bet it's a wash cost wise. Can anyone in the business confirm, dispute, or add their own insights into this?

In mass production situations, the cost of materials typically do not factor in as much as the actual fabrication process (there's also handling and storage costs as well, but I won't discuss that). I would imagine that the molds for the plastic pieces costs a lot more than a couple of mandrels, benders and tig welders. Of course, we should also factor in time, things that are labor intensive (fab and/or installation) usually suck up more of it (i.e. laying pre-pregs for composite parts). Just my $0.02.

Ford put an aftermarket intake on a factory car ZX2 S/R. Thats the only car that I know of.

I think the two main issues that manufacturers deal with are noise and ease of maintenance.

What is the number-one complaint that so-called "enthusiast" automotive journalist have against the Protege? The engine is too loud. And, from having sold cars of many makes, I have found the vast majority of buyers don't want to hear the engine at all... not at idle, not at WOT. Heck, they don't even want to hear the engine when the hood is open! In many people's mind, a noisy engine means lower quality. Manufacturers spend millions of dollars a year (combined) designing and testing intake systems to be as quiet as possible. Take a look at this pic of my stock intake removed. Everything there is designed to quiet intake roar... efficiency is a secondary priority.

http://www.caliprotegemeet.1hwy.com/...ntake Full.jpg

The second issue is ease of maintenance. The stock air filter is very easy to get to. The filter box is easily accessable and you just have to release two clips and its opened. It is not that way by coincidence. I haven't even checked or cleaned the filter on my Injen CAI. You can't see it from any angle and it requires unbolting of the front bumper cover to get to it (from what I hear). One of these days I'll get to it...

I think some folks have said that you can remove the black plastic splash panel in the wheel well to get to it. Only a few screws hold it in place if I recall correctly.