Thats correct, the engine was kept under load by a dynamometer and the load was varied to change the RPM. Am i right in saying this is the same situation at with a constant speed prop? coarser pitch puts a higher load on the engine, thus reducing RPM ?
if that assumption is correct then yes i'm generalising what i saw in the labs to what i'd expect to see in the air. I must admit i've never observed changed in MP with changes in RPM simply because I haven't been looking for it (and i wont be flying for a few weeks so i thought i'd ask for help here)