You are correct, it basically routes more air into the engine. It also has an air pickup from under the front valance as well. It isnt restrictive like it seems to look rather increases the amount of cool air reaching the intake. At speeds above 80 mph you can sometimes actually hear the shaker sucking air in, kinda cool. Increased cooler air flow at higher speeds is a good thing
. Some have even called the system a poor mans supercharger. Actually, if you close of the air pickup from the valance and removing the heated air near the road surface, you can get better gains from the system as a whole. Ford merely added the valance pickup as a backup in case something were to get trapped in the scoop( small birds, chevys) and blocked the air flow. Hope this helps.
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