Instead of putting the restrictive factory airbox back in the truck, we installed a Banks Ram-Air intake system. This modification helps get the most power out of the tuner since colder air is denser. More air mass decreases EGT and smoke while improving fuel economy because there is more oxygen to mix with the fuel. The 4 1/2-inch bellows allow for engine movement. This is very important, because a failure here could let in unfiltered air that will ruin an engine and turbocharger.