Here's the pile of pipes. Two factory headers (with extensions already welded on). Two crappy headers that came with the bike. And the aforementioned U-Haul table leg. We also used some conduit scraps from work that we salvaged, but they are not in the photo.
I took a bunch of measurement photos for reference.
We ended up cutting everything with a hacksaw and shaping with hand files. Yes we have power tools but there is a bit of zen peace you get from cutting and shaping by hand when it comes out just right. I may have used a grinder here and there for quick touch-ups but almost everything was done by hand.
These washers were cut down and filed to be the endcaps of the mufflers.
This was a test fit onto a sample of conduit for the inner baffle.
We didn't have any muffler packing, but we had a ton of that terrible fiberglass muffler wrap. I figured we should put something in the cannisters to reduce resonance, so I loosely used some wrap around the baffle pipe. The fiberglass dust got on everything. Ugghh. Not fun stuff.
I used a long threaded rod and spacers and nuts to hold the cannisters together for welding. We shaped the endcaps with a chamfer so the tension on the rod would naturally form the cannister-wall into a seal when it was pulled tight.
My buddy did some the of the welding on the connector pipes. He has a tig setup while I was using my flux-core. So there are some differences in the welds. Sometimes the tig was better and sometimes the mig was better.
When two people are in a rush, it really multiplies the chances for errors. We did most of the work in little bits of time just before going to work. So there was always a hard deadline. Racing the clock does not make for great quality work, but we're both so busy it was the only way we could do it. I was glad to have him take some of the welding load. He was already on another deadline to get the U-Haul camper done before he and his wife went on a two-week road trip.
One snafu was due to a miscommunication. of what areas were ground (to remove zinc plating etc.).
We lucked out in that most of the botched areas were in areas that were going to be out of sight.
Are you happy with how it sounds?
I'm planning on making a similar exhaust for my scrambled Z400, but going for a high level stainless steel system with both pipes on the same side.
I'm going to use 1.5" going into 2" muffler packed with exhaust wadding, so I should think the sound level will be about the same as yours.