Hi nice job man, only I would suggest to open up the hairpin slightly more with a mild bend towards T11 to create a more flowing entry into T12, and also open up the first proper left corner of the lap T8, therefore T7 needs to be moved down about 50 meters. The run-off will still be big enough for that part of the turn.
I abused your sketch too but like this it's more clear what I mean
You managed to use the space quite effictiently but only 4100 meters length, that is included the current oval?