the valve is uneffected by the jumper mod. since the jumper mod still shows an increase even with an aftermarket pipe. in which case, the valve is eliminated.The jumper mod I am aware of refers to the valve in the muffler of the 05+ 636 that closes at 13K rpm. Installing the jumper tells the ecu that it is a UK bike and leaves the valve open all the way to redline.
Is there something I'm missing?
well, the theory of low end is no longer a theory. it(valve) does NOT help, in fact it hurts it.it does every thing u said and the valve u dont notice it on a aftermarket exhaust cause if already flows better.
the valve in theory helps with lowend and emmison.