What % gain does a Warm Air Intake yield?
 

Does anyone have some A-B-A tests to show? I keep hearing it helps, but how much does it help? How do I do it? Will my 2001 Accord run properly with it, or will I have to buy higher octane gasoline?

As you can see, I'm confused...

I have a scangauge II so I can check results, etc.

Well, this is one of those things no one can really say. It depends highly on the car, the temperatures, and other junk. The best way to tell would be to test it for yourself with a SG

it helps some cars and hurts others, I like to think it helps my corolla, but i havent done any actual testing (besides the throttle response sounds cool when/if i ever have to step on it. )

You don't have to use higher octane. It's just you have less O2 in the air so you need less fuel to run. You will have a little less power and need less fuel. On my Suzuki Swift it makes i think about 4-5%.

It's like the same with a Turbo. A turbo compresses air, so you got more air and need more fuel. And as a side effect you have also more power :D. I know someone with a Swift with a turbo went from 40 MPG to 25MPG.

You may need higher octane when you change ignition timing.

I can say with some certainty that a WAI neither helped nor harmed my FE. Interestingly, it did quiet it down some, vs. the CAI.

SVOboy -

I would be leery of using the SG to quantify the actual % gain. From what we (think we) know, the SG is using an algorithm to determine MPG, and the IAT is a significant parameter in that algorithm (see here). The ECU/PCM, however, is using the 02 sensor's Air/Fuel ratio to determine how much fuel to inject.

CarloSW2

Modifications that reduce the maximum horsepower do not necessarily reflect on the fuel usage at other throttle settings. The main potential benefit of WAI is to aid fuel vaporization, and to quickly turn off the rich "starting" mixture setting.

Thanks Bob!

If you're right, and I assume that you are, then I'm not going to mess with doing a WAI. My car is garaged, and goes into closed loop almost immediately.

Another thing I have read is that the warmer air is thinner. This in theory allows you to open throttle more reducing pumping loss.