A Subaru WRX & STI intercooling solution.
To address intercooling there are a number of kits out that relocate the intercooler and some conversions that go water to air. I'd like to make a case to subaru to do both air to air and wter to air and I have a simple cost effective way to accomplish this.
1. Run the water to air system off the engine coolant. Using a radiator with more frontal area as radiators are already very efficient and most of the heat transfer is done within an inch or so (at least with slow moving cars and airflow). next run the air to water intercooler just off the turbo, you wont need a very big one (think lotus Espirit or even a little smaller). There after run it to the top mount air to air intercooler and back to the engine.
2. Run a high pressure water pump and divert a small amount of water off the cool side to the intercooler.
This will require a new water pump design.
The trick to getting the water back into the radiator is in the intercooler design, the cooling pipes need to be one way only, more over the intercooler will produce outflowing water temps far hotter than the engine requiring a system to equalize the temps.
That brings us to the part where money hits ideas, I've designed my share of thermo/ fluid dynamic machinery I can tell you that getting it to work properly is the other 90%, not too big of a deal for Subaru. The huge upside is an excellent inexpensive system running colder than anything out there and solving more than turbocharger outlet temps.
In my time benchmarking cars I've become a fan of the WRX and am looking into a purchase or lease. I think Subaru is making a dangerous decision in expanding its line while ignoring the WRX and the fan base this model created. I would explain that the sales of the other models are a byproduct of such a following and the envy of every single automobile manufacturer including the exotics.