RE: Nitro % question
Blazer,
The RPM difference from changing from 15% to 30% nitro fuel is typically ~200-300 RPM.
The fuel consumption is ~30% higher with the 30%, so your overall fuel costs will skyrocket.
Changing from down 30%; you'd be surprised how frugal your engine has become...
You would have to close both the high-speed and the low-speed needles, by a significant amount.