Is Water to Air for me?
A Water to Air Intercooler setup is similar in principle to a traditional air to air setup, except that there is water passing through the core of the intercooler instead of air which is responsible for drawing the heat out of the intake air. There are many benefits of using a water to air intercooler setup.
Water to air means incredibly low pressure drop.
Pressure drop on a standard water to air intercooler core is only .05 PSI. That's not a typo, pressure drop on a water to air intercooler setup is up to 20 times less than a comparably performing air to air setup.
Water to air means better engine cooling.
Many people who try to road race with a front mount intercooler have overheating problems because the air going to the radiator has to pass through the hot intercooler first. With a water to air setup, you have far more flexible options. The core will probably be in the engine bay, and the radiator can be mounted in the trunk, under the car, or in some applications a radiator is not even needed.
Water to air means better throttle response.
Instead of the horrible mess of pipes that is normally associated with an air to air intercooler, a water to air intercooler can be mounted in the engine bay, directly between the turbo outlet and the throttle body. A shorter intake route with fewer bends is beneficial in every way.
Water to air means no heat soak.
A water to air intercooler setup circulates water through the core even when the car is not moving. This is especially useful during drag racing, when the core temperature raises significantly during a pass, and then the car sits still for several minutes waiting for the next pass.
Why does it work?
Water does a better job of drawing the heat out of metal than air. Look at engine cooling - how many air-cooled engines are there? Not many, because water does a much more effective job at cooling. So much more, in fact, that it is impossible to engineer a solution for a modern high performance engine that is air cooled.
How does it work?
The reason it is easier is because you have extreme flexibility as to where to mount all of the components. Mount the core in the engine bay. The air inlet/outlet should, of course, be piped in between your turbo and throttle body. The water inlet should come from the pump, and the outlet should lead to the radiator.
If it is so great, then why does everyone use air to air then?
The reason is simple. Custom water to air intercooler setups have always been extremely difficult to build because they require so many unique, expensive components. However, now we are offering all of the components in one Kit. In the late 90's, everyone started using air to air front mount intercoolers because of their many advantages and very few drawbacks. The next trend is water to air.