Magnum Flow Stage 1 Intake System (51-10651) by aFe. Filter Series: Pro Dry S. HP Gain: +4 hp. TQ Gain: +5 lbs. x ft. Includes: Air Filter, 1-Piece Air Box. The Stage 1 Cold Air Intake System is a quick and inexpensive way to gain horsepower and improve performance. It replaces your factory air filter and airbox with a large free-flowing aFe air filter and open element airbox/heat shield, dramatically increasing airflow to your engine. For a little bit of time and money youll get a noticeable gain in low end torque and horsepower.