intercooler water spray

[sambb]

Wondering if I could get a little help with setting up an intercooler water spray system. I've been wondering what the exact mechanism is for the water cooling on the core itself.
I had always thought that the water droplets were evaporating off the fins of the core in realtime and its this evaporation on a surface that causes a temperature drop on that surface. If this were the case , would it not be more effective to spray tepid water (ie underbonnet temp) that would be closer to its evaporative threshold once it hits the surface of the core? Surely spraying chilled water (ie poured in just before a hillclimb start) would just cause a delay in the evaporation?
I ask because my core is often completely wetted down at the end of a hillclimb run. In this state would any actual evaporation happen or would it just be the core transferring heat into the water itself with very little evaporation happening? Perhaps I actually need to spray less water (as finely atomised as possible) to make the system more efficient. any thoughts appreciated.
thanks
sam

[Speedfreak24.7]

From what I have seen the majority of motorsport water injection systems actually inject a mist of water into the air charge that goes INTO the engine cooling the inlet charge. Also as with rally or drag racing. Sometimes methanol is used when lower grade fuels are required by regulations.