When setting up idle 3 for inverted flight using half stick of zero degrees- how much throttle should the heli be set at as to prevent overspeeding (seeing as to how there will be no loads on the engine at 0 degrees of pitch)...

...I used the 9CH's graphs to plot out a smooth V shape and came to about 20% throttle- would this be ther right way to setup the amount of throttle?

(10 degrees positive turns out to be 100% ATV and 10 degrees negative is also -100 ATV....- hover turns out to be 60% of servo travel in either direction - so from 60 to 100 is a 40% servo move- so I deducted 40% movement from below 60 to arrive at 20% throttle- is this right????)

I hope I haven't confused you guys....I'm just figuring this stuff out myself- I can't fly inverted but want my friends to try my Q30 and want to set it up correctly in case they'd like to try some inverted flight on my machine.

If you have any other setup tips- feel free to post them.
Thanks experts.

Just set it up so that at 0 pitch the head speed is where you want it i.e. 1750. You won't overspeed at 0 pitch but at a power descent. That will be controlled by the engine mixture and or pitch and throd curves.

I think that 20% is too low. I worked into mine by looking in normal mode. I set my 25% collective stick setting for 0 deg pitch, with hover at 5 deg at mid stick. I did power descents as in setting up for autos at 1/4 stick and listened for head speed. I added about 5% and this is what I set for the bottom of my V-Curve. It ends up between 35 and 48% on my 3 helis. You just don't want to overspeed or drop the head speed too much.