Well did you take into account the dimensions of the Ripp Vortex unit in comparison to the Prodigy Unit? Size is a big deal. What about the gear ratio that Ripp uses in the unit-- that matters. In your turbo, like the one on my diesel it is only run on exhaust gas pressure; so lower rpm means less pressure on the rear turbine so less Boost. Where as a supercharger usually has a gearbox so that at low rpm it creates a significant amount of boost.