The R-11's were only 'junk' in the eyes of the bureaucrats and number-crunchers.
The R-11 set was made specifcially as a 'test train' for the then proposed Second Avenue Subway. When the line didn't pan out the order for additional cars was scrubbed. However, the R-11's had better ventilation and ligthing over previous car orders.
Because of their experimental status they could not be fully integrated into the rest of the NYCTA's fleet and remained 'orphaned' throughout the remainder of their careers (mostly based on the Franklin Avenue Shuttle under their rebuilt designation, R-34).
Having ridden on the cars in the early 70's, I can state with much authority that the R-11's were far from 'junk'.
BMTman