Injen SP1978BLK: Air Intake Nissan Altima 3.5L V6 04-06, SP Series Black Cold Air Intake System (Converts to Short Ram) (SP1978BLK) by Injen. The SP Series Cold Air Intake System is made for the enthusiast who wants maximum horsepower from a tuned cold air intake system. This cold air system positions a high-flow air filter behind the bumper, where it can take in cooler, denser air. Cooler air contains more oxygen for more complete combustion and more horsepower. This system can be converted to a Short Ram air intake system if desired. Up to 15.6 HP and 19.4 ft.lbs TQ Gain.