Your truck’s stock air intake system is designed to be quiet and cheap to make. Manufacturers know they are leaving some horsepower and torque on the table, but they have other things to worry about. Things like the overall longevity of your truck and all the other parts that work together to tow your big boat to the lake; or race car to the track; or some villain’s beach house off its foundation. They don’t judge; they just want your truck to work when you need it to.
But in the aftermarket the air intake system is considered the low hanging fruit of upgrades. A cold air intake system is probably the easiest single upgrade you can do to your truck that increases power and torque and even fuel economy, all while keeping your precious engine from being destroyed by dust and road dirt.
They are called “Cold Air Intakes” because they are designed to pull air from outside the hot under hood areas. They can pull air through the grill, or through the side fender, or sometimes from the bumper area. The reason cold air is more desirable than hot under hood air is that cold air is denser than hot, meaning more actual air can be ingested by your engine making more useful power.
S&B Filters makes cold air intakes for Dodge, Ford and Chevy/GMC diesel trucks. These intakes are elaborately designed to completely replace the stock air box. They are easy to install as they are computer designed to bolt into the same space as the original air box, while making space for a much larger air filter and larger air inlets. S&B is famous for giving you more than one air inlet; with the option of sealing one to keep noise down; or leaving it open for maximum power. Another nice touch is the clear cover on top of the air box, giving you a view of the big filter.
AFE Power makes heavy duty cold air intakes for diesel trucks from all the major manufactures as well. Their most robust intakes are the Momentum HD Pro DRY S Cold Air Intake System. It requires no cutting or drilling of your truck to make it fit. As an example, the version they make for the Ford 6.7 litre diesel truck increases air flow 21%, gives an extra 12 horsepower, and 32 foot pounds of torque. This performance improvement can be installed in an easy afternoon of wrenching in less time than it takes you to kill a six pack of Raspberry Schlitz.
HSP Diesel makes cold air intakes for Duramax motors. These intakes feature 4 inch tubing and many colour options to make things pretty under your hood.
Last, but not least, is the Stage 2 No limit 5 inch cold air intake kit from PPEI which will outflow any other intake on the market for the 6.7 litre Powerstroke. This system looks more like the traditional cold air intakes where the filter is exposed to the under hood elements. This makes for tremendously exciting intake noise when you stomp the throttle, all while boosting power and torque, and even improving fuel economy by 1 mpg.