My attention has been drawn to an article that appeared in Classic Bike Guide for Feb 2012.https://covers.magazinecloner.com/covers/37920/mid/0000.jpg
Norton Blackcap Silencer - the inside story.
Brian Dolman worked for NVT on developing/ improving the black cap mufflers, and details the stuff they did to test and improve them.
Significantly, he mentions the best results were with a balance pipe in the exhaust system and a distance of 28 inches from the port
seems to have given the best results - improving both the low end and higher rpms torque, as well as keeping a healthy midrange.
That would place it somehere about under the gearbox, the actual pipe isn't shown, or how they achieved that.
A little hand drawn dyno chart shows the results though, 55 bhp (engine hp presumeably). Quite healthy for a Mk 3.
And reports that by then, management weren't interested....
The 1st part of the article was Oct 2011, anyone got this issue ?
Or seen the discussion.
Hmmm, my guzzi has a balance pipe in the zorst under the gearbox, wonder where Brian went to work after NVT ?