It's a dumb idea for a few reasons... first off, with turbocharger technology being as advanced as it is today, you can have a high HP setup with minimal (read: almost none) lag. Also, since positive displacement superchargers (Roots type, like the JR unit) are around 50% efficient and will only add to the thermal rise of the intake charge.
Basically... after the turbo heats the air up some, the blower is going to heat it up a TON. How much is a ton? Typical blower outlet temps are around 250°F above ambient. Add the 150°F from the turbo, and you're at 350°F intake charge temps. But it gets better... That 250°F is assuming that the blower is ingesting unpressurized atmospheric air. The design of the Roots blower is such that it will take whatever pressure it recieves in the intake and add to that. So... we have 10 PSI from the turbo, which is already hot, and add 8 from the blower that adds more heat, but since the blower is already working with compressed, hot air, you can't just add the two temps together. I have all the math formulas on my other computer, which is in storage at the moment, but an off the top of my head guess would put the intake charge temp after the blower at somewhere around 425° for that setup.
Generally, everything has been tried in the way of power production. If you don't see it being used today, there's a good reason...
