Fluid MotorUnion’s mechanics run through four different exhaust pipe/header configurations on the Shelby-tuned Ford, from the standard factory setup through to the all-guns-blazing custom header ...

The 80mm exhaust fan is thermally controlled and supposedly runs as follows: 3,100 @85c; 2,600rpm @ 65c; 2,100rpm @ 45c; 1,800rpm @25c. Good to know, but it doesn't help out much.