One of the reasons I'm definitely a fan of Superfastmatt on YouTube isn't just his dry, hilarious sense of humor; it's all the cool design and engineering work he does. More importantly, it's seeing how he manages to shepherd those ideas from his brain into actual parts for whatever he's building. Although a lot of it is cars (including the parts you'll see in this video), sometimes it's bikes, and the processes outlined here could easily work for any powersports vehicle you put your mind (and money) into building.
We've talked a bit about 3D printing in the past, from professional racing teams to startups using it to make entire motorcycles. In both cases, although the parts being made were obviously pretty robust, they weren't actually made of metal. Sure, custom CNC fabricators exist and have done so for a while, but having more tools in your wacky, dreaming brain's potential toolbox isn't really a bad thing, is it? I didn't think so.
The part of this video that might make your jaw drop (as it did mine) will probably be the exhaust headers. Depending on your skill set and the tools available to you, you might be able to whip up whatever exhaust header configuration that your project needs on your own, from raw metal. And that's awesome; I love that for you! But at the same time, I also love that there's more than one way to reasonably get to the particular customization path you want to go down, such as 3D printing your exhaust headers to your design specifications.