[HELP] D16Z9 swap into EK - Alternator Problem

[beavis]

hi ppl . i recently swaped a D16Z9 into my EK Chassis and used some OBD2 parts , as the crank pulley from my old D14 engine(european model) and the OBD2 alternator.

After the swap , i noticed that my starter was a little weak and my dash lights also , so i measured with a multimeter and i was surprised , because even with my engine running i get only 11, 5 volts....

I checked the belt , and tension is correct , i raise to 2000rpm and still 11,5 volts , so the crank pulley is not the cause ( the D14 one is a little bigger but lighter than Z9 one),, afetr a short ride i noticed that the battery goes away , and stops the car , so can i conclude that the D14 alternator is not enough to the Z9??