The Rotax triples are a nice conversion and will make the power when built properly. Still one of my favorite engines. I have to wonder why you oppose the turbo idea? Here's what I tell guys I talk to about wanting to turbo a ZX or Rev chassis. After the initial investment my turbo kits can be changed over to the other chassis if you step up into a newer chassis and take the turbo kit with you. I will build a kit for a ZX and Rev, but our production units are for the XP. If you have any questions call me or pm me, I don't check the general section much.
Dave Halverson