I just did my first loop yesterday. I have a Raptor 30 V1 with the TT 36. I had symetrical glass blades on. I flew full speed forward and pulled back as it went from 9 to 12 I heard the head speed drop, which scared me. I had started reducing pitch and hence throttle. The rotor sped back up as it came over the top and downward side ( as I transitioned back to positive pitch) of the loop was uneventful.

After 3 loops I decided I needed a mix to goose the throttle when giving hard cyclic. That worked wonders, I hardly lose any head speed now. My mix adds up to 20% throttle linked to % of cyclic input.

Jason