[Old Crow]

Yeah, Orrie, you may be right about that, but as a kid all I cared about was the sound.

Then I spent 6 years working on GM motor homes and learned about the hidden spring adjustment for the secondary air flap. The problem we found mostly was the air flap not opening, not the actual secondary blades. Back off on the spring and the flap would open, even with the stock air filter in place.