Superchargers and turbo chargers do to engines, what bellows do to a fire. Valve overlap changes help even more, using the compressed air to scavenge the cylinders of burnt fuel. It’s all good!
There are draw backs though; Compressing air creates heat. It’s still got the same heat energy, but now it’s all squished into one space. The higher the boost, the more heat there is in the ‘charge’. For even better performance it needs to be removed. This makes the air less viscous and means more expansion in the cylinders.
The down side of cooling is greater air volume between the compressor and engine. The higher the volume, the slower the boost pressure is to rise. This can mean annoying turbo-lag, which is why some racing disciplines remove the intercooler completely and link turbo and inlet manifold with a short pipe. Others fit huge intercoolers and never let off the throttle. But there is a third way!
The charge cooler is a little used item with many advantages. It’s not for major car manufacturers, who buy intercoolers for £20 each, but it might be for you! The construction is simple enough, being an intercooler that’s cooled by water instead of air. Water can store a lot more heat energy than air, so the equivalent charge cooler can be much smaller. This reduced package size means it can be placed closer to the turbo charger or inlet manifold and can even be built into the inlet manifold. This gives a two fold advantage to turbo lag, in that the air volume is less in a charge cooler, and there is less hose work required to plumb it in.
As the circulating water is cooled at another location, there can be twin coolers either side of the engine rad, so main engine cooling doesn’t suffer from a large intercooler stuck on the front.