Solved

Mandatory wet pit

Is mandatory do a pit stop in a wet race?
Game makes me stop in the strategy but not sure if I can ignore that in the race.

No. 

Though the game doesn't allow a no pit strategy during setup, you can get around that by setting your number of laps for your first stop beyond the length of the entire race.

So, for example, if the race is 50 laps, set your first stop at lap 51. Then just set your second stop for whatever.

Thank you