If you have it on 45 now, start at around 30 and vape. Not doing it for you? Turn it up a little... say... like to 32 and vape. Repeat that until you get a slight burnt taste and then back it down a few. That should be the sweet spot for that juice.
Another thought just came through. How long have you been using the current coil? It could be that you need a new coil.