The stock ECU's can be reprogrammed w/o needing a daughterboard to compensate for bolt-on upgrades. I was under the impression that a daughterboard was only added to control NOS or a turbo safely, with the daughterboard holding revised timing/fuel/ignition maps when boost/NOS is added versus stock settings on the ECU. Go to
www.jimwolftechnology.com, get their contact #, and verify this with them. They do the majority of Nissan ECU reprogramming.