Kevin,
While no one would be happier than I if your predictions came true, I do believe they are overly optimistic. I will state my reasoning, and you can then poke holes in it
First off, we need to differentiate between air
mass and air
volume. Air mass is a function of how many gas molecules -- nitrogen, oxygen, etc. -- are present, which is crucial as oxygen molecules combine with hydrocarbon molecules to produce the power we all crave. Air volume is a function of air mass, air pressure, and air temperature (the famous PV=nRT equation).
Now, compressors (supercharger, turbocharger, whatever) move air volume -- which is one of the two main reasons power falls off as intake air temp rises. Hotter air is less dense, meaning lower mass per unit volume, meaning less oxygen to combine with hydrocarbons and produce power. Intercooling does nothing to help this, since it's downstream of the compressor. The compressor moves a given volume of air, and that air -- cooler, denser, but no more massive -- is what emerges from the intercooler and enters the engine. Thus, I believe the statement that "cooling the intake charge in itself WILL increase power" is erroneous on vehicles without knock sensors -- the effect is NOT analagous to driving on a cool night because you're not doing anything to cool the air entering the compressor. This also was the point of my comment regarding the Supra TT ICs -- the power increase they see is NOT coming from increased airflow into the engine, because the turbos are already maxed on those cars.
The addition of an intercooler also introduces a flow restriction into the intake system, which manifests itself as an increased pressure upstream of the intercooler. This increased pressure in turns means less air flow at a given compressor RPM (see for example the compressor maps at
http://www.turbofast.com.au/FlowTO4E.html for an illustration). Thus it is actually possible to LOSE power with an intercooler, if it is too small for the application.
For these reasons, "Bolting on" an intercooler to a supercharged car may, by itself, do very little. If (to pick on Max) the car in question is already tuned to run with un-intercooled air temps, then no additional power will be had by adding the intercooler, as you're not changing the mass of air entering the engine (see above) and you're not changing the timing to take advantage of the lower intake temps (see below). As a case in point, I once "bolted on" an air-to-water intercooler on my Dinan supercharged M3. That car DID have a knock sensor, so it was able to take some advantage of the IC by increasing timing advance. It went from 276 to 285 RWHP, a gain of under 4%.
That said, intercoolers DO allow an FI engine to produce more power. They do so in two related ways:
1) They allow the tuner to run more boost and/or more timing advance. The lower air intake temps quench detonation by reducing combustion chamber temperatures. This effect is most pronounced when the compressor is running at/near the high end of its efficiency range, and is heating the air substantially. Outlet temps can run 100-200F above intake in such situations, and a good intercooler can reduce that differential to 30F. This accounts for the majority of the gains to be had with an IC, but it requires a car with adaptive timing (i.e., with a knock sensor) or additional tuning.
2) They allow more air mass into the combustion chamber by increasing the density of the intake charge in the intake manifold. This effect IS analagous to the "driving on a cool night" scenario.
Finally, an expansion on my point about "systems". I don't know Max's car's configuration (sorry, Max) but if he's still running the stock fuel injectors, he won't have enough fuel to safely support 20% more RWHP. Also, if he's running stock cats he'll have progressive flow restriction from the exhaust side which will limit his HP increase. And so on. You cannot expect to just slap on an intercooler and see horsepower appear -- at the very least, you'll need intake and exhaust flow capacity and fuel system overhead to support the additional power, and you'll have to retune the car and the boost.
OK, fire away.