MX100,
What is GJ? For your question I used sheet styrene for the manifold baseplate and styrene tubing for the exhaust tubing and used a pair of tiny needle nosed pliers to bend and shape, then used Tenax-7R plastic welder to attach all pieces. turbo and compressor are made from heated tubing and the inlet on turbo is made from larger diameter tubing. I can't explain this very well- I just build it. I'll show some finished pics in a few days. Give it a try. Its not hard-just a little creativity and a will to finish. It takes practice. Good luck !!
Walter