Many have asked about true dual exhausts for Harleys. There are some advantages and some disadvantages to the systems.
True duals will loose a bit of torque on the bottom end from the loss of scavenging but some like them for looks and sound in any event. It's a personal preference for the most part. They will also remove some of the heat on the newer bikes from the under leg area because of the absence of the pipe from the rear cylinder that exits out the right side.
You also have to be careful which mufflers you run when you change the pipes to true duals. The stock muffler on the left side on 07 up bikes has very little flow to force the exhaust to exit to the right muffler which provides scavenging. This is due to the baffling in the muffler on the later models.
Using the TD setup with stock mufflers will cause a problem for the rear cylinder because there will not be sufficient flow to exhaust the cylinder. Changing to slipons like Vance & Heinz , Reinhardts or the equivalent will solve this problem and allow both cylinders to breathe properly.
Reinhardt True Duals have a stepped header design and end with a larger diameter pipe then the stock setup. The Reinhardt true dual mufflers only work with the Reinhardt true dual head pipes.
Also see this tip...
Full-Sac exhaust - Harley Davidson Community
True duals will loose a bit of torque on the bottom end from the loss of scavenging but some like them for looks and sound in any event. It's a personal preference for the most part. They will also remove some of the heat on the newer bikes from the under leg area because of the absence of the pipe from the rear cylinder that exits out the right side.
You also have to be careful which mufflers you run when you change the pipes to true duals. The stock muffler on the left side on 07 up bikes has very little flow to force the exhaust to exit to the right muffler which provides scavenging. This is due to the baffling in the muffler on the later models.
Using the TD setup with stock mufflers will cause a problem for the rear cylinder because there will not be sufficient flow to exhaust the cylinder. Changing to slipons like Vance & Heinz , Reinhardts or the equivalent will solve this problem and allow both cylinders to breathe properly.
Reinhardt True Duals have a stepped header design and end with a larger diameter pipe then the stock setup. The Reinhardt true dual mufflers only work with the Reinhardt true dual head pipes.
Also see this tip...
Full-Sac exhaust - Harley Davidson Community