Once the 1M engine is warmed up (after the usual ± 30sec cold start-up rumble sequence - varying rpm to quickly warm up the cats to operating temp):
- if airco is not operational: idling around 600-650rpm;
- if airco is operational: idling around 650-700rpm.
So, for those who want the lowest pitched 1M engine sound note during idling: switch off the airco for a slight sound pitch drop (around 50-100rpm less). Eventually resume airco after idling.
OT: mere guess, but I assume normal idling for most Ferrari engines is at least 1200rpm.