Fill fill fill,
How many times do we have to go over this?
Every motor made has a very specific valve timing, exhaust flow, backpressure balance point to achieve optimal performance and engine stability. The good folks down under in KiwiVille have found the exact sweet size, shape and design to achieve this highly sought after balance. You can still play with jetting and the such, but the basic balance in exhaust valve pressure and backpressure are constant, unless you start messing with the cams and valve sizes.
There really is a HUGE difference in performance from the various pipes. I tried several iterations and dynoed them all and the difference is right in front of you in black and white.
With that all said, in my opinion, I repeat in MY opinion, there are really just a few pipe manufacturers that worked towards this performance balance end result : Bub and Thunderbike being the top of the heap, D&D next.
I would love to find a dyno this May down in Ga and spend a few hours just swapping pipies with say open air boxes and 130 jets. A good medium point with just the different pipes and see actual printouts. That might make for a very interesting "Techno Talk" afternoon eeh guys? I wonder if a portable dyno could be rented for a reasonable amount, hey, with 20+ riders chipping in some $$ I bet it can be done.
