Building an exhaust

[mioraet]

Anybody who knows stuff about exhausts feel free to put in your 10 cents worth...

I've obtained a Yamaha TDM 850 which is way too quiet. Given the relative rarity of these on our roads, I am picking that a well priced after market system is going to be unobtainium.

What I was thinking (I use the term loosely) is, can you take a couple of cans off a similar displacement twin and build a system around them as long as they fit?? It has to work obviously with no big holes in the power delivery. Quite keen to construct something as the bike is as loud as a bernina sewing machine at present and the factory 2-1-2 with collector box probably weighs a ton or two...
Opinions please..

[Sensei]

Open core the original's is the easyest & cheapest way to go & shouldn't effect the performance but help if you don't go crazy inside them & make them to free flow . But you can see about getting some ones off Trademe but then if from a different model they may not work either without modifiying them as well .