Up until just before christmas I has Motad stainless pipes with a straight through end can, with 110 Keihin jets and on a tank (from full to reserve) I could just about get 90 miles before reserve most of the time, mostly riding sensibly with the odd flick of the wrist to overtake someone etc.
I fitted the Dic alu system and rejetted to 110 Dynojets as recommended by Graeme France, and not only have I noticed that the bike is a bit pokier (bit dead under 4k, ballistic much over 9k) but it's better on fuel, I've got 109 miles so far without hitting reserve, I had to check I hadn't left it on reserve last time I was so surprised! If I've worked it out thats a bit over a 22% increase for increasing the fuel flow, and also, seeing as it's new and loud I've been riding like a bit of a tit where it's possible, with lots of high revs and wide open throttle

Anyone got a good reason for this?