Its not wise to make schedule by flying at the upper limits, that makes no economic sense at all. Keep your initial cost index (which is probably around 8 or so), request directs, hit LRC if you want to gain a minute - nothing you can do will make a considerable difference
RTA is on progress page 2 or 3 depending on the software bits, punch in the initial approach fix, take your scheduled landing time, subtract eight minutes or so, put that into the RTA field, expect RTA UNACHIEVABLE in the scratchpad
