Digital BW, The Print

Does anyone know the setting to use in the Epson ABW color wheel so that only K, LK, and LLK inks are used?

I am only looking for ball-park; I can imagine other colors will also be used, but preferably only slightly.

I know I can use QTR - but therein is the problem. My 4800 with custom inks is giving me banding with QTR, yet is silky smooth with ABW.

Thank you.

Shilesh