I'm curious about the stock exhaust... is it like the KFX400 where it has metal baffles with offset holes or is it more like a performance exhaust with a straight shot through the center just plugged up with something?
I have yet to see any dyno numbers on the stock exhaust etc. But take this into account. The LTR with the lid off and full DASA system only made 2HP more than the same set-up with the stock exhaust.
Point is, no one knows for sure if the Stock exhaust is complete junk. I know for sure with teh bafle out and lid off witht he power commander, the bike wakes up nicely, I have my KFX to prove it.
For PEAK performance an aftermarket exhaust is the way to go though.