Well Alessondro has said, that with the Brullen Cat-Back and the Brullen Y-pipe, that the sound of the exhaust becomes a little deeper. It adds to the already throaty sound of the Brullen Cat-Back. But the awesome thing about this y-pipe is that it eliminates the drone produced by the stock and SHO shop y-pipes. This is due to the equal length. If you have any other questions please ask. Thanks
