I'm not sure the dogma is quite dead . . .AZRickD wrote:thebleakness wrote: . . . In my 2003 KDX220 with the head, carb, and reed mods, the rev pipe mutes the bottom half of the RPM range while not doing anything particularly earth shaking or useful in the upper RPM range. Your 220 might be different, but I kinda doubt it, and nobody here has done the research to prove otherwise (or at least they haven't bothered to post during the last seven times this subject has come up).
I've proven to myself that this Fredette-based conventional wisdom on the rev pipe for the 220 is not all it's cracked up to be and might not be worth the trade-off in low-end torque that a fleeting hint of upper revs brings.
This dogma has died.
Rick
There are a number of factors that would need to be considered, right? I don't doubt your words - better performance for YOUR 220 when you compared the pipes running your 220 down the street.
There's so much more to consider.