also keep in mind that as the rotors spin, it's creating a fan/vacuum effect where it's pulling air from the center. So airflow is not just dependent on front air pressure from the opening in the duct.
One thing to keep in mind - if it's a dual purpose car and you're driving in very cold temps you may want to tape up the ducts when not at track.
When I was doing one lap at daytona, at the end of the oval going 150mph the brakes would cool off enough so that I'd have to apply the brakes a little to warm them back up to get the pads to bite hard
