Modding exup valve to stay open on stock exhaust?

Check out the comments from Chuck Graves:

"Motorized actuating plates can fool the system into believing that it has more volume than it really does. This coupled with cross overs and cambers can smooth out the torque curve dramatically. The factories have done a tremendous job at this with rules being considered.
Think of it like this 14 PSI pushing at the back of the pipe and 14 PSI at the intake track. The waves are always changing. Anytime we can mechanically interrupt the 14 PSI at the tail pipe from affecting the exhaust speed at exit we are winning. This is a very simplified way of explaining it. I could write a book detailing the benefits of the mechanical valves.


Think about the exhaust stroke when its job is done exiting and the short period of overlap with the intake. During this period and depending on the RPM VS Throttle Position a condition can occur where the cylinder receives some of its filling from the exhaust port. This is bad!! It causes the exhaust speed to change and in some cases change direction. Change of direction can happen easily on a single cylinder machine much easier. Attacking the wave heading in the wrong direction is an art. Tappers, crossovers, collectors, motorized actuators, tubing diameters, silencer cores including hole sizes and pitch, shape of the silencer exit and much more.


Wiring the EXUP wide open with the stock system will in most cases cause a loss of power depending on the tuning of the EXUP from the factory. I cannot be sure on all bikes since I haven’t tested them all. I can tell you that there are gains to be had from EXUP on the FZ10 and R1. Flash the Graves Slip On map in a stock bike and you will see this. The maps are free to any user of FTECU software and downloadable from the FTECU file manager."

Cheers,

MrHix