Is pīti physical and sukha emotional? I always read piti: joy is mental happiness and sukha is physical. But lately i have been reading pīti is physical, sukha is emotional. At first i thought this didn't matter but now for Jhana training I'm reading move from the piti physical sensation to sukha emotional sensation, which completely throw me off. Any help?
Can't separate like that. Mental-emotional-somatical is a continuum, not discrete. Or, more precisely, they are layers of the same, like different frequencies that can be isolated within the same signal function - not separate. 

Sukha is that mental/emotional state/feeling when everything is just right. Everything is just the way it should be. It feels peaceful, subtle and sweeeeeeet. It also has somatic component. The breath becomes fluid, the body feels light, the movements are spontaneous. It's like that feeling when you just woke up after wonderful sleep and you feel refreshed and blissful, gentle and peaceful.

Piti is a much more coarse condition. It is like that feeling when you listen to a very inspiring lecture or a song and suddenly realize - and feel - profound significance and gratitude, and then you may get goosebumps or the tears may start rolling. Somatically at that moment, you may feel being aflame or tingling or orgasm-like waves going through your body. Unlike sukha, piti is kinda taxing, one can get tired of it.

So yeah, piti is coarser of the two and sukha is subtler - in this sense you could say, piti has a stronger somatic component and sukha is more focused on the mental/emotional end of the spectrum.