Setting amp gains with vehicle smart charging alternator

[Miatakoss]

My new used car has a smart charging system Ford Focus 2007. I just installed a 220 amp alternator however at idle it only puts out about 12 volts until you tip into throttle and then you get 14.7 14.5 consistently. I've never installed amplifiers in a car like this so when setting the gains on the amplifiers, is it best to slightly ramp-up the vehicles RPMs to attain the 14.4 or so voltage for proper gain setting? Anyone with experience on this I would love any information knowledge you name it so I can get these set properly, thank you very much