The Power Now Plus works by controlling the air stream after the slide. At lower throttle openings (idle to half open), the area (diameter) between the slide and carb throat in front of the slide causes the air to expand or “break into the larger area quickly. In a stock carburetor, this airflow is uncontrolled and spins around. By reducing the area in front of the slide via the Power Now Plus, slicing this air into two smaller masses, the airflow does not break as far, and cannot spin. It is forced to move forward filling the cylinder in the shortest time and making the most power at lower throttle openings. The result is instant power gains.