Product DescriptionBolt-In Collector or Exhaust Pipe Velocity Venturi Tube. Fits inside 3.5" OD Pipes or collector *Creates a venturi from backpressure *Back-pressure is increased at low speeds resulting in increased low RPM power and torque. *Increases exhaust gas velocity at high speeds. At low speeds, the tapered venturi increases back pressure resulting in increased low RPM power and torque. At high speeds, the venturi effect increases exhaust gas velocity. This maximizes engine power by increasing the rate at which the exhaust gases are drawn from the exhaust ports. Laymen description: Imagine water flowing through hose, if you pinch the hose, the increased back pressure accelerates the speed of the water. Other sizes available |