Getting started with Aerodynamics

[UNGN]

Opening the back of that hood is most likely going to add air under the hood, not remove it.



Abandoning the factory grill opening and getting all radiator air from a deep core support airdam is the best way to go 150 mph in a street car. Trans Am's, corvettes, etc don't have above the bumper grills for a reason.

A NASCAR car, running on a smooth race track can have a front facia 1" off the ground, while a street car cannot. Unless the front facia extends to the ground, the relatively high grill opening will promote front end lift... unless its blocked off.

A Deep core support airdam is liveable on a street car, much more so than effective Chin spoiler or splitter that is deep enough to overcome the lift generated by the grill opening.

If front end lift is still an issue after you've blocked the grill off, then you can extend the chin spoiler until it is isn't anymore. The Chin spoiler you end up with would not be as deep as you would need with the grill open.