I sketched out a plan view ( bird’s eye view ) for the shape of the pipes by just putting the car on a piece of paper and outlining where the pipe should hug the contour of the car. I then cut that piece out on the bandsaw making sure that I left a little extra wood for the details of a heat shield and a tail pipe extension that I wanted to add.
Then, by holding this wavy piece of wood up against the sides of the car, I traced in the lines where I wanted the pipe moving up the side of the car and over the rear wheel. Then that got cut out on the bandsaw…very carefully. When I don’t have a flat surface to rest on the bandsaw table, I make sure that I’m very aware of where the wood is going to get pulled by the blade…and I always use a push-stick so that my hands are well away.
With a bit of shaping, it all fits in pretty nicely under the chassis and over the rear wheel.
This next photo shows the progress that I made on the rear suspension leaf springs as well. I made the rear axle assembly, epoxied it into a recess that I made and then made the leaf springs ( it actually looked a lot like a clothespin at one point ) and glued them to the axle assembly. An Engineer at GM wouldn’t be happy with my design…but I think that most carvers would be ok with it.