I've welded several small projects for one customer's turbocharged Harley Davidson motorcycle. I've never heard turbine whine coming out of a motorcycle exhaust before. It looked like a pretty nice cruising machine.
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One bike project was splitting a single exhaust system (ceramic coated stainless steel) into a dual system. The customer wanted the "sleeper" dual exhaust look (as a turbo is not expected with a dual exhaust.) I removed a small amount of ceramic coating around the area where the weld needed to be and welded a "Tee" branch he prepared, with a custom internal air deflector to help persuade some of the exhaust gas to take the side branch. Here is how the end result looks after being installed underneath the bike (it's pretty hard to see this location in casual bike observation):
Attachment 1948
Another project was a custom boost gauge mounting bracket designed by the customer. This was highly visible, mounting in a central, focal point of the bike's instruments. Originally the customer just wanted me to weld the side fillets of this 304 stainless assembly he brought in jigged up "ready to weld". Since he was going to polish it down afterwards, I encouraged him to let me weld the front and rear faces as well, being very careful not to undercut at all, so he could grind/sand the weld bead down and make the two pieces disappear into one. That's what we ended up doing, and I'd say it turned out pretty good!
Ready for welding:
Attachment 1944
TIG welded:
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After smoothing, polishing, and installation:
Attachment 1946
He seems to be really good at polishing stainless steel. When I first saw it, I though it was chrome plated it was so reflective!
A third small project on this bike (that I haven't seen installed yet) is some sort of low-mounted stainless steel sheetmetal bracket or cover, about .065" thick 304 stainless material. I just welded the pieces he gave me together in the way he had them arranged, all lap welds. I can weld these without oxidizing the back side very badly with low heat input (DC low frequency pulsing is helpful.) He said he was going to polish it out before installing it also, so I am looking forward to eventually seeing the end result. Here is what it looked like after welding:
Attachment 1945
I generally used a #8 gas lens cup with 15 cfh argon on these.