I posted about this in a different thread. I don't know about Evos, but I've tested this with a friend on a '01 1.8t GTi. He's repurposed his rear wiper sprayer to mist the IC. He also mixes alcohol with the water.

The results were a 20*C drop in intake temps (according to the ECU). I would assume that the results on an Evo would be similar, if not better. The VW's have side mount IC's and get much less air flow that the FMIC's on Evo's. I would think that more air flow would give better evaporation results.

 

03 evos already have i/c sprayers

 

is it for sale?

 

So how much alcohol would be mixed? Half and half?

 

I get yelled at by the tech crew when ever I use mine before a 1/4 mile run, so they do deliver water.

 

I can't remember exactly. I don't think it was 50/50. I'd think it was closer to 4:1 mix (water:alcohol). I'll talk to him and report back.