gamelay quarter lengths vs simulation quarter franchise mode

Could some one please provide some assistance. I am playing (attempting to at least) a franchise mode for nba live 09 on my PS2. I wish to simulate non user games at 12 minute quarter lengths. However, when I play the actual games with my franchise team, I don't want to play 12 minute quarters, due to the unrealistic scores and stats that develop. Does anyone know how to adjust played quarter lengths to 8 minutes, while leaving the sim quarter lengths at 12 minutes? Thank you

It cannot be changed for the PS2.