Yesterday I had the parts all finished up. I put the diffuser disk in the body tube and blew through the center hole, and it had some "backpressure" (as compared to blowing through a "Grieves") so I added the two round holes, which brought things where I thought they should be. I figure maybe the two round holes will make some extra turbulence and mix things better in the stinger chamber anyway... It was about 40 today, so I raised the garage door about 6 inches for ventilation and went at it. TIG welding is truly an art, and I've trashed a lot of thinwall aluminum tube to get to where I'm at... I'm a BSEE by training, and TIG welding is kinda like riding a bike - I can explain all day about how to do it, but until you figure it out by doing it....
Anyway, the welds are definitely a bit on the ugly side, but they hold the stuff together well, with no leaks. The two mufflers are only 4 ounces heavier than my set of stock BME pieces (I don't have a set of stock DA mufflers...) so I figure I did OK. Now I've got to get started on the aluminum headers to match up with the mufflers!
