Every word of CB's post was spot on. You can never adjust the charge correctly on this system after the condenser airflow has been increased over its engineered value, unless you make a few other modifications. One of those is the piston size, just in case you don't remember that post that I spoke to you about. With the old piston and higher condenser airflow the system is mismatched. The subcool will run too high and the superheat will never correspond to the superheat chart over the range of ambient temps that the unit runs under. Moreover the system will be easier to freeze up, i.e. it will do so at a higher ambient than it did before. Even when you change the piston out, the indoor air volume will now be a tad too low since by increasing the condenser airflow the capacity of the unit will be a tad greater than before. Now don't get me wrong, the system will work, but it will never work as it was engineered to work. Put a TXV on the evap coil and you have yourself a blanket fix to all of these potential problems.
Now there's the issue of the under-loaded condenser fan motor and premature failure due to overheating. This can be fixed by selective capacitor sizing as a hack fix, but it isn't supported by the motor manufactures unless you have the trip-saver, but I'm not even going to go into any of this with you since you already have enough to digest for one night :)
hvacrmedic
hvacrmedic