Casper,

I have a 1600cc M45 engine running 18psi and very hot temps out of the SC. I spray right after the IC (100% meth) to give the longest mixing and cooling time. I have tried spraying before the SC, I really didn't see much change, as the mass of the case is so much that in normal driving it didn't seem to help. Maybe in a endurance race with a sustained spray you could lower the temps out of the SC.

Do try to put the jet as far away from the manifold as possible, right after the IC if possible. Water doesn't turn as easy as methanol, so the more time to evaporate and mix the better.

I've used this example before, on a 100F day my SC outlet temps at redline is 350F, and the temp in the manifold in the midrange is 60F climbing to 110F at redline.