[duplox]

A few things.. I'm suprised no one has mentioned water/alcohol injection. Basically, you have a nozzle that sprays a mix of water and alcohol(rubbing alcohol works fine) into the intake, when water and alcohol atomize, they reduce charge temps by a huge ammount. It also has the effect of cleaning your combustion chambers, so it prevents carbon buildup. Carbon buildup will increase your compression ratio and hot spots in the chamber, making it more likely to detonate.
Also Buzz1167, your calculation for intercooler efficiency is wrong. 200* discharge temp is right, intercooler efficiency looks about right, but a 133* temperature drop is impossible. That would mean that your charge temps are now 67*, when the outside air temps are 100*. Intercooler efficiency isn't just compressor discharge temp * efficiency.. this is the formula:
(Tco - Tio)/(Tco - Ta) = E
Tco is temperature at the compressor outlet.
Tio is temperature after the intercooler.
Ta is ambient temperatures.
E is intercooler efficiency.
So rearranging the equation for temperture after intercooler you get:
-E(Tco - Ta) +Tco = Tio
so for your example, -.65(200-100) + 200 = Tio
-.65(100) + 200 = Tio
-65 + 200 = Tio
Tio = 135*

As for air to water, if you have a large enough water cooler out front, it should do better than a air-air setup, unless you drive your car hard. If you just occasionally floor it, air-water will work great. The more you push your car, the bigger the water cooler out front will have to be. Water transfers heat much much better than air. It requires a much smaller core compared to an air-air of the same efficiency.. smaller core means less pressure drop, less pressure drop means less compressor discharge boost for the same manifold boost, less compressor discharge means lower temps... so with the same intercooler efficiency and same manifold pressure, an air-water will have lower intake temps than an air-air. The problem is keeping the water cool. If you only have a small cooler out front, then yeah, air-water wont work so great. For my turbocharged v8, I'm going to be using an air-water and a big A/C condensor radiator(same size as my radiator except thinner.. 26"x19"x1" or something close to that..). I like air-water better mostly because when I do go to the track, I can fill it with ice water and get 100%+ intercooler efficiency.