The aftercooler is essentially a system comprised of two heat exchangers, a pump, a reservoir, and a coolant. One of the heat exchangers is mounted (welded) on a plate on the bottom of the RSX JRSC access plate. The other is mounted in front of the car much like an intercoolers heat exchanger. The hot JRSC air is cooled by the heat exchanger within the JRSC. The water flows constantly through the JRSC's heat exchanger, through the pump, and through the front mounted heat exchanger. This keeps the coolant nice and cool.
JRSC Heat Exchanger
http://i218.photobucket.com/albums/c...DSC00252-3.jpg
Mounted on the JRSC
http://i218.photobucket.com/albums/c...k/SNC00027.jpg
Methanol Injection is just like what it sounds. You have a trunk mounted reservoir, a pump, some lines, and an orifice (nozzle). You fill the trunk's reservoir with some methanol/water mix and shoot it directly into the intake. This allows for cooler intake temperatures and gains with tuning. Usually 20-40whp and 10-20wtq on SC'd A2s and K24s. I believe a membere here has a tuned A3 on methanol injection hovering at just a littler over 270 to the wheels.
Together they are good for about 50-70 hp on tuned A2s and K24 motors. Id expect close to 300-310 on a properly tuned A3 with good supporting mods.