As promised, here are some pictures I took of the propane turbo snowmobile in development. This is the Arctic Cat that I believe he developed it on before going to the Yamaha. I honestly have no details on this kit. If people want details I can call him up and ask. But I don’t think they even went to production with this version. As far as I know they only produced the Yamaha version. Again, I think these are being sold as Simmons Propane turbo kits. Not sure what happened to the HP^3 concept.
So as you can see. This one is a propane turbo kit for a 2-stroke engine. The 4-stroke version of course is basically the same. You just don’t have the expansion chamber. And tuning is probably a bit less finicky on the 4-stroke. Although my dad never complained about tuning on the 2-stroke. But he wouldn’t. He would just get it done and make it look easy. He’s pretty damn good at that kind of thing.
BTW, here is some more shots of him out on the snow. I am pretty sure I stole these off his computer. No idea where they were taken or by whom. Also, these look like they are the Yamaha Apex, not the Arctic Cat.
Just post a comment if you want more information or better pictures. I could probably figure something out.