I first noticed the low fuel economy and major loss of power in a rainstorm. It acted like the choke was on. Examining the air filter showed that there was water pooled in the housing. The ram air hose (which has since been replaced with clothes dryer hose) channels water in during a storm and saturates the paper air filter element.
After much head scratching, I bought a $22 electrostatic filter from Ace hardware designed for home heating units. It was disassembled and the element layers cut into strips. An old Fram filter from my car was stripped out to just the two big rubber rings and the mesh inner ring, so that what I was left with resembled a spool.
I wound the new strips on this form maintaining the original order of materials in hopes it would still have the electrostatic filtering properties.
The difference in fuel consumption was immediately noticeable, and the losses on rainy and muggy days is gone.
I examine the new filter periodically, and rinse it with a garden hose if it needs it.
It does not use a power supply. The element I am referring to is simply layers of dissimilar plastic that generated a static charge as air passes over them. Take a look here: http://www.riteair.com/filtercat.htm?ai=00020001
The claim is it removes 97% of particles, but there is a companion spray to make the element stickier at $5. You can used Pam cooking spray.
Yes, water in the air filter housing IS a concern, but that was one heck of a storm on the freeway.
Cool. I wonder if there is a way to test if it is still maintaining the same properties (static cling?!?!?! Where's my electron microscope when I need it!!!!). I would think it needs to be changed out more often, but maybe not.
Interesting idea. I wonder what the benefits are as compared to a high flow cotton gauze filter.
As far as water pooling up in the intake, it takes quite a bit of water to hydrolock an engine. In high humidity, the air being sucked in is saturated with water. An internal combustion engine is just as much a water pump as it is an air pump. However, if the filter is soaked you're not going to get much flow through it and that's generally not a good thing. Also, water present somewhere in the intake tract will occupy some portion of the available air flow volume.
I see no reason why fuel economy and power cannot coexist.