The 550 size is slighty bigger than the 540 motor in the tt-01,mine runs a bit hot after 20mins or so all good then,if you think its starts running too hot get hold of a fan to cover the ESC/motor those pc fans are pretty good had one running on a 9v battery on top of my motor to keep it cool in the sunshine
sounds like that ESC is a 20turn limit as the tamiya standard silver can is a 27t you could probally drop a faster motor in if u wanted too just saty around 21turns that what i have in one of mine drfits well on pvc too [8D]