The intercooler needs to place in an area that receives the front air to achieve this purpose, to become a “refrigerator” at full capacity. Generally, if its dimensions are large, it is usually placed in the central-frontal part. When it is smaller, a usual position is in the front wheel passes.
It all starts at the moment when we demand power with the accelerator pedal. At that same moment, the turbo blades begin to work, so that they begin to aspirate atmospheric air through the filter.
The advantage that the intercooler placed in a location that receives a large amount of outside air is that it will not take long to cool the airflow that comes from the turbo. If we continue to accelerate, the intake manifold will have the throttle open, and the pistons will request more air. As we can see in the drawing, right now, we would be in the colored part of blue (which refers to a cooler air), which enters the pistons and expels to the turbo exhaust shell (which connected to the exhaust pipe).
In summary, the air enters with an outside temperature in the intake shell, with the pressure heated, the intercooler cools it and sends it with the proper temperature to the engine. Although in the first instance it may seem like a most normal and common invention, the intercooler helps supercharged engines give their best.