[nak]

There is a way for water spray to spike the temps up instead of down.

If the water hits the IC and is heated but not flashed to steam and it is not forcded by airflow through the IC, you have a problem. The initial hit takes heat out of the IC and warms the water. Then this hot water sticks around and restricts air flow through the IC. These cars are not noted for good IC airflow to begin with.

The key to good cooling is flow rate, period. It could be air or air + mist BUT IT HAS TO FLOW to take the heat away.

A very fine mist, in the right quantity, would lightly and evenly coat the IC, heat up, and then evaporate away in the airflow. THis would boost heat transfer in the expected way.

 

[nak]

water isnt gonna just hangout in your intercooler and restrict airflow(if your intercooler is hot enough to flash boil water you have SERIOUS issues) its going to absorb heat and evaportate and if it doesnt air will push it out

even if the air didnt push it out it would still absorb heat and evaportate

there is no way for water spray to increase charge temps unless the water you are spraying is hotter than your intercooler(and even then it might evaporate fast enough to help), thermal energy only flows from a high concentration to a low concentration...

if water spray increased charge temps then how come you dont start to detonate when it rains?

It's about flow rate.

If the water doesn't evaporate (the IC is not hot enough to flash the water to steam) or move through fast enough (low air flow was what got us here in the first place), that water will heat up (a good thing) and then stay there (a very bad thing). If the water build up restricts air flow, the heat isn't being carried away by air and the hot water isn't being carried away. Fine fins and low air pressure could make it happen. The hot water blocks incoming cool water as well. If the water heats up enough and blocks airflow well enough that heat flow into the water is lower than the heat flow into the dry air used to be, the IC performance drops.

If the water evaporates or flows through quickly, it should carry away more heat than air alone. This should be the normal case. Like most everyone else, I was thinking that adding water mist can't make the IC worse. Unless it kills the flow by clogging up th IC.

I think we both agree that the only real steady state cooling comes from mass flow through the IC.