I've been playing with the idea of modifying the air intake on my mostly stock AE86. As I searched the net for some examples only a few popped up. I've seen some posts that show people moving the intake to the inner fender with a cone filter mounted. I should start by saying that I am no professional mechanic, however, I was a jet mechanic in the USAF on F-16's so I do have some knowledge on the theory of how engines work. Please correct me (respectfully) if I'm wrong with any information below. My first thought was - if more air passes through the stock filter than a cone why would I not use the stock air filter. The only info I can back this theory up with is forum advice, but it seems that the thinner more porous stock filter would allow more air to pass through. I am not saying that it is the better of the two, just the higher flowing of the two - if this theory is even correct. From that point I thought about how to redirect cold, fast moving air to the current air box setup. I removed the left blinker with plans to move the blinkers to the fender lights if my idea would work. I thought of using the hole left from the removed blinker as a way to funnel air into some aluminum tubing that runs in through the bottom of the airbox from under the fender. This idea seemed easy enough to fab but the length and amount of bends needed for the tube to reach the air box was more than I anticipated. I'm not sure if this would have a great effect either way but the mockup looked "messy" for lack of a better term. The last idea, and the one I am looking for advice on is the idea of flipping the airbox cap (the top section containing the filter) upside down, and cutting an air dam in the hood to redirect the air down into the filter. My two main concerns are water and whether the sensor contained in the cap will function properly if flipped upside down. i.e. -would gravity effect the sensor? Any advice or help is greatly appreciated.

This looks like it would float your boat:

http://www.racerpartswholesale.com/category/Naca_Ducts2

The stock filter is more dense/better filtration than an aftermarket K&N deal. It's a trade off, better filter less flow OR more flow less filter. Youre thinking down the right path though of feeding cold air to the filter. Every 10 degrees you drop the intake charge is 1hp. I thinking cutting the hood will make baby jesus sad, but adding one of the naca ducts would be racecar-ish. Flipping the intake upside down shouldn't effect the sensor, but like I said, I think a nice duct-plumb job will meet your needs without confusing onlookers as to what is going on in there.