In response to this quote:
Originally posted by suzmcman
A guy I know is putting a slip-on on his 1000 and stated that he has heared that if you do any more then that you will kill your bottom end and hurt the mid range some. I don't remember what pipe he is using but you might want to check on this if you are thinking of a full exhaust.
PS. Your header I believe is titanium
This is a frequently heard rumour which circulates around, pertaining to liter bikes with the special exhaust valve systems designed for more low-end torque. Specifically, this exact same rumour circulates around the YZF-R1 with its EXUP system, the CBR929RR with its HTEV system, and the Suzuki with its EXUP-cloned valve system. The gist is this: these special valve systems alter the exhaust flow and air pressure depending on what rpm you are at, and are designed to get you more low-end torque, then at high rpm they open-up and get out of the way for the engine to run at high intensity. The story we hear is this: if you replace any other part of the exhaust system except for the muffler, you'll be removing the EXUP-style system, and therefore getting rid of your low-end torque advantage. Well, it makes sense logically, and that's why we hear the story all the time. But on the other hand, I hear people say the best thing you can do is totally get rid of the system, it is more of a nanny to keep the power buildup more linear. If you go to www.hardracing.com
for example, you can see their special article they have there about the HTEV system on the CBR929RR. When they rip the whole stock exhaust system out and put a full system in, they have huge horsepower and torque gains everywhere, across the board. The horsepower gains on the 929RR were something like 14 ponies
, which is rather impressive, and comparable to what the other guy said in this thread with the GSX-R1000 and the full Yosh system, that he gained 13 ponies. Myself, I don't have any direct experience to corroborate any of this, but I have seen the dyno printouts which, if true, confirm it, that the best thing you can do is rip the shyt out and put a full system in, and you will gain power and torque across the board.
Hope this info helps,