Bios Mod To Change Min Fan Speed

I have a request but not the typical request around here, i have an ex485 which i upgraded the cpu however it heats up to fast and shuts down, because of the fans are not controlling correctly the temp to prevent this, i looked through the bios settings but didnt find where to alter this, maybe it has to be done on the "behind the scenes". can anyone help me with this and change it or point me to the right place

the mod bios can be found here

http://adapt.gen.nz/files/bios/EX48X_2011_02_20.zip