[olddog]

Rambling thoughts:

Shelby and his racing team had to think the turkey pan was doing something benificial or they would not have waisted the time and money.

Since the frontal area that air flows into the radiator is small, my intuitive thought would be that the under hood area would be at a low pressure, when going down the road.

Since the turkey pan is open, there will be no ram air affect, however the question is which air has the higher pressure? If the hood scoop air is at a higher pressure than the under hood pressure, then the cooler outside air will be flowing through the turkey pan, out the holes, and into the engine compartment (minus the air sucked into the engine). If this is the case (I suspect it is), cooler air is a good thing, providing flow restriction does not overwhelm the good. When going down the road at speed, I would have to think the air flowing through the scoop would have to be moving fast enough to overcome the restriction of the pan.

Seems like a simple thermometer in the air filter with the pan on and off would answer half the question.