Here are some pics and a graph showing the newest header I've built for my WR250X. I've been trying to broaden the power in the upper rev band without loosing snap off of the bottom. This is the 3rd version for this particular bike. Not a huge difference between the peak numbers, but the power is up 1-2whp from 8k until the rev limiter. Torque was up around 1wtq from 8k out aswell. You can definately tell a difference on the street as it feels much more eager to rev.