After some research on downgrading GT5 from 2.17 to 2.11, I think this should work:
1- Delete your Gran Turismo 5 game data, along with all savegames
2- Start GT5 and let it update to the 24th out of 27 updates (which is 2.11), allow the 24th update to finish installing but CANCEL before the 25th finishes downloading
3- Allow GT5 to install game data normally
Note that you will need to stay logged out of PSN whenever you start GT5, lest you are pressured into installing 2.17 again.
Last edited by
me_brewsta ; 10-30-2016 at 04:09 PM.