Increase flow area up to 103% over the stock 2-3/4" boost tubes with Banks' huge 3-1/2" OEM left and right side boost tubes. Stock hot side tube is dented at the factory, bringing it's diameter down to a tiny 2-1/4". Banks boost tubes are 3-1/2" constant diameter mandrel bent with larger radius bends. More air allows for more fuel which means more horsepower.