My thought is both a pipe and tune issue. The SE legal tuner is very limited. Just not using the prescribed pipe from hd is enough to blow the tune. Couple that to a less than great tune to fix that and low relative compression and this us what happens. Everything must work together. The shorter cam would not help.
Okay so it's time to say goodbye to the SEPST and get a aftermarket tuner. You say pipe also? I thought the V&H Power Duals was a good head pipe? I understand the Fullsack is better but I was under the impression it was OK?
If you had real tuning devise (TTS recommended) and some one that knows how to use it, you would be amazed !! and even better if you set compression. What muffler do you have?
I have the Khrome Werks HP Plus 4.5". Love the sound of them but not sure if they are creating enough backpressure for what I need.
This is off of KW website so take it for what it is and these numbers are from a M8.
Engineered for performance, style and sound. These mufflers have been dyno tested and show 12% increase in torque and 7% increase in power.
Yes TTS is on the top of my list & PV is my next choice.