My experience a pump whining means there is a restriction causing the pump to have to work harder. You changed the filter and strainer, so my next check would be the fuel dampener and pressure regulator, and also verifying your return line is not restricted.
Getting a reading of your fuel pressure with a gauge off the rail would be first step, making sure its within spec (see clarks below).
Fuel Pressure Regulator - General Information and Replacement
Fuel Pressure - Checking
"The Bosch fuel pumps used in Porsches are generally extremely reliable and not prone to failure. If you have a fuel pump that needs to be replaced, there is likely something else that has caused the fuel pump to fail. So, before you simply replace the fuel, you may want to see if there is another problem that caused the fuel pump to fail. A clogged fuel filter can cause failure of the fuel pump.
A failing fuel pressure regulator can also result in pump failure. It's a good idea when installing a new pump to perform a fuel pressure check and pump delivery rate check. This will check the condition of the entire fuel system and may prevent pre-mature failure of the new pump by identifying potential system problems."
FUEL-10, Fuel Pump Information and Replacement