The 07 had great low end power and the 08 exhaust system is redesigned so I was thinking this had to be the reason for the lack of low end power on the 08. Thanks for the explanation.
It may have something to do with it, but they also changed the cams in '06, again in '07, and again for '08. There's also the question of the advance curve
, which is the only significant change made among the 3 distinctively different '03-'05 models.
The exhaust might well be a factor, though. I know that low end power was improved a little on my own '06 by adding a Dr.D
system, and I've seen reports that exhaust mods have improved the '07. One guy stated that all he did was to put the end cap from an '06 on his '07, and that that gave the low end a boost. Exhaust systems are "tuned" by selecting their diameters and lengths (in the most simplistic sense), and by the positioning of "steps" in the pipe, to control the timing of pressure waves within the pipe so that they arrive at the exhaust pot at a particular moment. These waves move at the same speed regardless of engine speed, so the pipe only "works" within one narrow RPM range. Below that range, the best thing to do for increased power is to reduce any restriction to its lowest possible level.
I clearly recall that when the '06 came out, most people complained that it had weak low end. The same complaint was made about the '07 at its introduction. It's kind of funny, don't you think, that each of these 3 bikes has been criticized for being weak off the bottom, but when the next successive year comes out, they all of a sudden have great low end power?