Driving in the rain has always given me higher fuel economy and the hot dry season here really kills fuel efficiency. This is how I simulated high humidity conditions to give me that fuel economy boost in the rain.
Step 1: Pump and Reservoir.
I used an aftermarket windshield washer pump complete with reservoir. This provides good pressure and flow for the intended project.
Step 2: Programmable Timer.
This frm01 12v timer I programmed for 0.2sec on, 5min off, infinite cycles. It switches the 12v power from the accessories circuit to the aftermarket windshield washer pump.
Step 3: Installation and Results.
I used a length of nylon tubing to make a ring at the top of the cone air filter. I drilled a dozen small holes on the inner circumference of that tubing. A Tee fitting completed the ring sprayer. To ensure the engine breathes only air through the damp section of air filter, I sealed off the top section typical of cone filters.
The pump and reservoir I bolted near the engine radiator. The negative wire I connected to chassis with the positive going into the cabin via the firewall. The timer relay is mounted inside the dash.
Since Commissioning this project, I have gotten an extra 60km per full tank of gas. I am most pleased with the results here. During drives the engine idles smoothly in traffic and has slightly better power during acceleration. This project is similar to water injection without the direct misting of water into the air intake manifold. The benefits for my implementation will not be as large as a water injection setup but the fuel savings is what I'm after.
A downside to this project is the air filter frame has gotten rusted. I don't mind since I have several spares and for the fuel savings involved, changing the air filter every 4 years is worth it in my opinion.