I see that no one answered your question so I will try.
I am not sure when the RPI comes out other than end of season.
Boyd Nation does a good job of psuedo RPI.
RPI really means little (to me anyway) until end of season, when the NCAA tournie field is announced. Top RPI teams usually get the regional, which of course is an advantage in the tourney.
Fresno State's RPI was 51 last year, it certainly doesn't determine who will win the championship, just helps getting into the field of 64.