Originally Posted by skr00zloose
some bikes, like the 929/954 and the new gixxers, with the valve in the exhaust, actually LOSE power in the lower and midrange with a full system. they make a bit more up top, but 90% of the riding on the street isn't done at or near redline.
There is a guy on gixxer.com that does alot of tuning and so on, and said that they havent been seeing a noticable lack of power in the low/midrange on the new gsxr's with full systems that dont retain the exhaust valve. there are rumor's that its actually just for noise emissions over 'lower end power'. dont get me wrong, my 06 gsxr600 has plenty of low end and mid range power, alot more than a 05 gsxr600 i rode a while back.