Some stuff out there on getting the speed out of the hydros. I’m still experimenting. The stack was really simple. Bent a piece of pipe, welded on a home made flange to mount it to the motor, drilled a bizillion holes in it, took a larger pipe made plates for the top and bottom, drilled those to fit the “exhaust” pipe and the top for the exit stack, made a flapper and welded it all together. Works great and sounds kinda badass. Lol