when I have a soph with a 3.5, I will generally give him 4 or 5 mins and work down if he does okay
if a soph starts the year with a 2.3 earned as a freshman, I would start him at about 9 as a soph and work down or up as needed
for a junior who comes into that year with a cumulative 2.3, I would start him at 6 or 7
all this assumes that you are not at DI or DII in which case you would want to be sure that the kid isnt a former nonqualifier for whom getting over 2.7 matters