M-106 (also known as M-106-1sk) was a M-105PF variation. Major distinction - single-speed centrifugal supercharger, providing intake pressure 1175mm.Hg. As a result, engine gained up to 150hp of output. The supercharger was designed by V.A.Dollezhal.
Other engine changes included:
Single-speed supercharger allowed to eliminate a power drop at 1850m, where M-105PF supercharger had a speed change. Elimination of this power drop (known to and exploited by Luftwaffe pilots) could provide Soviet pilots with certain advantage at low and medium altitudes, where most of dogfight took place.
Trials proved insufficient readiness of the engine. Urgent needs of war did not allow the team to fulfill development of the M-106. It was abandoned.