D&D Exhaust 581Z-31F Black Boarzilla 2 into 1 Exhaust for 2006-2017 Harley Dyna Models
2:1 Boarzilla exhaust system is a stepped header system at the head is 1 7/8″ to 2″ at collector and 2 1/2″ where the muffler goes to the header. All Boarzilla full systems are equipped with heat shields, exhaust gaskets, bolt kit and baffles. Each exhaust system is designed and dyno tested at their facilities. Every pipe is designed to increase low-end torque and horsepower. The Boarzilla 2:1 exhaust is for bikes that have 116″ to 131″ motors.
It also comes with both 18mm and 12mm O2 bungs so it can be used with an auto tune module such as the Thundermax Auto Tune.