Reply To: Training in SCY and racing in LCM
1. Long course times are slower than short course times since you have a turn and push-off extra per 50m in short course. A turn and push-off are always faster than continued swimming, you should take that into account when converting the pace to short course. At push-off you would reach a speed between 3.5m/s and 3m/s, during the glide a speed between 3 and 2.5m/s but good swimmers only reach about 2m/s during swimming (see: http://www.swimmingscience.net/2010/07/start-vs-push-off.html). So, suppose you target a pace of 30s/50m in long course, when training in short course, you should target e.g. 29s/50m (or even faster) to take away the advantage of increased speed after the turn.
2. Different coaches use different conversion methods. In my opinion it also depends on the swimmer, some have slow turns, some have fast turns, some have better push-offs, … It helps to have both LC and SC times for the same events. Then you can simply derive the conversion for a particular swimmer.
A related topic: http://forum.usrpt.com/forums/topic/400-free-set-recovery-question/