Originally Posted by
OHL
Brake cooling air is mostly taken from the front bumper for the front brakes.
The vents that you see in the hood are there to evacuate air that has passed through the various coolers in the front of the car. Air going in the front bumper then passes through the Radiator(s), Intercooler(s), Gearbox Oil Cooler(s), Power Steering Cooler(s), etc. then out through the vents in the hood. The turbo intake is also usually through the front bumper.
Air management through the front of the car is something that takes a lot of clever thinking and hours and hours of testing and design revisions. The air hitting the front of the car is both a blessing and a curse. It can cool, create downforce, cause drag and create lift all at the same time. How you manage it is the key. The are myriads of little splitters, ducts, guidevanes, block-off plates etc. all doing their part to help manage the air flow to get the desired benefit.