At first glance, the 5.4L GT engine may appear to be equipped with the same supercharger found on '03 Cobra Mustangs and Lightning trucks, but it's not. Ford opted for a much more efficient Eaton-built twin-screw supercharger that produces 12 psi of boost. The Cobra and Lightning rely on a Roots-type blower (also made by Eaton) that produces 10 psi for the Cobra and 8 psi for the Lightning. Inside, the secret to high boost levels on pump gas is the integrated air-to-water intercooler that rests between the upper and lower manifolds. After the air is compressed by the supercharger, the intercooler significantly drops the hot inlet temperatures to reduce the risk of detonation, all the while maximizing horsepower potential.