I don't understand much about this stuff Hanso but I'll try my best.On the air/fuel graph on the dyno print outthe lines start at 1200 rpm and on the air/fuel level it starts at 13 rises steadilly to 14 at 3000 rpm then falls steadilly to just above 13 at 5800 rpm. I hope this is what you wanted to know. My R3R with standard headers straight into one muffler first run 131.46hp - 152.48 torque. and alot of overun pop. After a few runs I ended up with 136.97hp - 154.61 torque and all of the pop exept for a superbike like bang at 1800 rpm on overun. witch appears to be to do with the pipe and not air/fuel mix. The dyno bloke said it was caused by cold air getting sucked back into the pipe and igniting so we tried disrupting the air flow behind the pipe on decel and we could stop it poping. So I came home and tack welded 100 ml long peice of exhaust tube on the pipe. It fixed the poping so Igot a reverse cone made up to go on the end of my pipe this looks better than the exhaust tube but still pops a bit at 1800 rpm but I'm learning to live with it.