I’m working on a custom, one-off exhaust system for a Yamaha XV-TR1. This has quite a few steps. Firstly I need new flanges to bolt the exhaust up to the cylinder heads.
If I can buy exhaust flanges with a few minutes searching on the web, then I’ll buy them, as thats generally quicker and cheaper.
However, if I can’t buy them, I have to make them.
These are the steps involved, and I’ve inserted a video below to show you, in eight minutes, how I did it.
- Measure the existing exhaust flange or exhaust port in the head
- Draw up the flange (I like to do it in scale, so I can confirm it is OK).
- Transfer the drawing to steel (I used 6mm mild steel plate).
- Roughly cut the flange out with an angle grinder.
- Grind and sand smooth.
- Drill the manifold bolt holes.
- Bore out the exhaust port hole (in this case – 44mm diameter – done with a holesaw).
- Quick clean, take off the sharp edges, and sand on the flat bench (mainly for looks).
Part 1:
Once the flanges are done, the exhaust build can start. The following two-part video shows a time-lapse of the build. The pre-bent sections are available online from exhaust/auto suppliers. This is one way of fabricating a custom exhaust. After doing a few of these it become easier, but you have to visualise how pre-bent sections (45, 90, 180 degree bends) can be used as-is, cut or modified to create a shape that you see in your head. You can see from the start of the following video that I had done some planning beforehand, and used this sketch to plan out what bends I would need (before I ordered them). Obviously the customer shouldn’t pay for parts not needed, so the planning process is part of making sure we don’t waste money on the build.
Part 2:
Part 3:
Contact me if you have any questions!
