Take a look at a normal turbocharged engine. It is straight-mounted with the turbocharger mostly flange-mounted on one side, which presses the intake air through a large intercooler up front, to the individual cylinders on the other side. A long distance to travel, which certainly does nothing to improve the, anything but exciting, turbo-response.
It's even worse in older, transverse-mounted engines in which the intake- and exhaust gasses flow in and out on the same side. In this case, the air flows around the whole engine before it finally reaches the intake valves. The intercooler prevents this by transferring its heat to the coolant instead of to the air.
Of course, it is not that simple, as a rule the coolant temperature is far too high. What we now need, is a two-part system linked only to the compensation tank. In addition, there is a small electric pump which the engine management only switches on when required.
Should the air-temperature difference before and after the intercooler be too small, or if the engine requires, at the moment, a particularly high power thrust, the pump provides the cooling. This of course, also happens when the engine is shut down and the turbocharger is still carrying too much residual heat.
Because the temperatur is being measured right now anyway, one can also register possible errors. If one takes a look at the the above picture, one can see that the whole thing is certainly more compact. It can take the direct path from the engine to the inlet manifold with integrated intercooler. 04/10