An occasional rider buddy recently decided to disconnect the H-pipe on a Late model Heritage. Slip on exhaust and breather already installed. When I asked why, it was stated he wanted to go True Dual exhaust for better performance. I suggested that what was done will not increase HP or TQ {and possibly decrease performance}. He started to get a bit huffy about my lack of understanding of the Harley System of exhaust. Before I wade back into this discussion, I'm looking for some opinions. Am I wrong on this? Surely wouldn't be the first time!!

 

You're correct. Whatever he did can't be bettre. If he wants true duals, then he needs a new system with a new tune.

 

the merge pipe helps in performance by increasing scavenging in the cylinders. exhaust moves in pulses. as exhaust passes threw one tail pipe it will create a vacuum threw the merge pipe in the other tail pipe assisting in removing exhaust and pulling in additional air and fuel

 

Yes, he has hurt performance as stal94 has described.

 

For the reasons stated above, it is obviously your riding buddy who doesn't understand the Harley exhaust system.