I admit my blog has gone a bit quiet recently, but in all honesty that's due to the fact that my shop is buzzing with projects and stuff. (Some of which I will quite gladly share in the course of the next days and weeks!)
I am lucky to have a friend by the name of Karl-Heinz, who already had faith in the exhausts I built for the Yamaha TR1 models, long before they were up to the standard they are now. So far Karl-Heinz did some indepth testing of my Mk.2 model. This is a 2 in 2 system, with downtubes of (almost) equal length. But various discussions via e-mail showed up the flaws of the design.
Due to the lack of a connecting pipe there was no additional scavenging and the individual cylinders had to be jetted quite rich resulting in a pretty dramatic fuel economy.
As such, when I decided to build a Mk.6 exhaust for myself, Karl-Heinz asked me for one for himself. A wish I gladly obliged.
So here we have the Mk. 6 on the bench. As you can see it's a two-in-one-and-a-half setup. Meaning, that I use the pulse from the front cylinder to help with scavenging, but also have a second exit just to make the rear can shift enough exhaust gas.