I am new to motorcycle exhaust system naming. What is a 2-1, 2-1-2 etc. mean?? What is the configuration name for the stock 2015 HD Ultra limited? I put the American Custom slip ons on. These are original HD mufflers with the baffles taken our. Can buy different baffles to insert if you want to change sound. I thought that was a good idea. Not sure what configuration to choose when I autotune after getting the stage 1. Thanks.

 

2-1, 2-1-2 and true duals all refer to head pipe. 2-1 front and rear cal run into one muffler.2-1-2 (stock pipe) front and rear run into one then split back to 2 mufflers. true duals 2-2 2 separate pipes and mufflers.