Turbos have to spool bro. On top of that, you are running immensely more air/fuel and the operating temps raise dramatically. The Banshee's have cooling and operating temp issues enough as it is before impeller switches, coolant changes, etc. I'm doubting there is a large intercooler system in place to dissipate this effect to a large degree. Even then, the turbos on a shee will be peaky and this will only complement the peaky powerband of the Banshee as it already is with just a set of pipes.
I'd really love to watch it though. I wish we had 2 quads available to test this out on. I'd love to watch the forced induction or drag related banshee on trails or an MX course for longer than 10 minutes. I'll throw down $$$ the engine is toast by the time it's over. I:I