Creating your own exhaust manifold

Is there a course/ class that shows how to create your own exhaust manifold. Thank you

Creating your own exhaust manifold can range in scope quite a bit depending on the number of cylinders, chassis, packaging, whether turbo(s) are involved, what tools you have access to and more, but HPA's Motorsports Fabrication Fundamentals course and Practical TIG Welding course include information on fitting, cutting, welding etc. which covers a lot of the process.

https://www.hpacademy.com/dashboard/courses/motorsport-fabrication-fundamentals

https://www.hpacademy.com/courses/practical-tig-welding/

In terms of design, if you're creating a turbo manifold, I found some great info in this HPA podcast with a guest who has been doing it for quite some time.

https://www.youtube.com/watch?v=zK0Mke-vyG8

Beyond that, there's a 3d modeling course if you want to CAD model your manifold so you can buy exactly the pipe you need and reduce fabrication time:

https://www.hpacademy.com/courses/3d-modeling-and-cad-for-motorsport/

Were there any particular aspects of the process you were hoping for more info on?

As Mike said, there's a lot to consider, and you can add material, wall and flange thickness, collector type, etc.

If you can give some idea of your experience, the equipment you have access to, the vehicle, what you expect from the manifold, etc. it would help point you in the correct direction.

Justin, at https://www.youtube.com/@TheFabricatorSeries - has some examples of fabrication you may find useful - and a lot more.

Jody also has some excellent general welding guides - https://www.youtube.com/@weldingtipsandtricks