[RedDevil]

FWIW, I started this thread years ago : http://ecomodder.com/forum/showthrea...i-27765-3.html
but I never came around to actually making the electric WAI.
But I did some tinkering.

On a very cold morning I walked around my car with running engine, as the windscreen was fogged up and frozen on the inside. I was running an e15 gas/ethanol mixture and could clearly smell the ethanol from the exhaust. It dawned how bad the combustion is when still cold.

The theory of heating up the air before it gets into a cold engine is that it would make for a faster and more complete combustion.
I did some testing with hot water bottles and measuring the effect on intake temp and warmup time.

What I found that heating the intake temperature (raising it from around freezing by about 20 degrees) actually increases warmup time slightly; the engine takes longer to get up to temperature.
That seems to confirm the theory; as the combustion goes faster (actually less slow) than when stone cold, a smaller amount of fuel can produce the same power.
The remaining fuel will eventually burn and heat the engine, but not produce as much power because it is late for the power stroke. Less of that means less heat.

I'm still looking for a suitable heater setup.
I'd prefer to have it on top of (e.g. beyond) the air filter, so the trajectory to the actual intakes is as short as practically possible. No need heating up the air filter itself.