Originally Posted by azkid110
what most people don't understand is that the air box is designed to pull in fresh air, most people get the CAI for the sound it makes, and the small performance increase. drilling a few holes into it will not make a big effect on performance if any at all, and you can possibly lower performance.
That's a rather rash statement to make.
It depends on the car. The majority of stock intakes on cars are designed to be cheap, and fit pretty well in the space thats given. We're talking sharp bends, tube diameters smaller than the hole in the throttle body, really really
long paths. It's usually a mess. An aftermarket CAI on average frees up about 10-20 horsepower on stock vehicles, depending on the stock design. The power gain increases exponentially the more power your motor makes, because it will need more air.
However, the most important thing about aftermarket CAIs is where they draw the air from. Most stock cars draw air directly from the engine bay. Yes, that is fresh air. However, as any high schooler taking a science class could tell you, colder air is denser air. Which means, air drawn from underneath the car (rather than air in the engine bay, hot!) will contain more oxygen for the amount of space that it takes up. This, in turn, means that more fuel will be injected resulting in bigger BOOM, also known as "more power."
It should be noted that CAIs are not a gift from the high Lord himself sent down for Circle K racers to masturbate on. But they do help. You will feel a difference.
And to finally answer the original question. No, drilling holes in your airbox will not act like a CAI. If drilled into the filter box, it may allow more air to reach the filter, but that isn't the problem with stock intakes. It's the bottlenecking from the small piping and convoluted path. Holes drilled into the piping itself will mess with your A/F ratio, since it won't be read by your air flow/ pressure sensor.
(This turned out to be much longer than I thought it would. Cliffnotes : You're both wrong. Have a good one.)