I think there's a slight difference between 'I lost track of the time' and 'I lost track of time'.
The first means that I was so engrossed in whatever I was doing that I didn't know whether it was two, three or four o' clock. I had no idea what the time was.
The second refers to 'time' as a concept - minutes and hours flying by. I was so engrossed in whatever I was doing that I had no idea how much time had passed.
Obviously, they amount to the same thing, but the angle is slightly different. I think you could say either.