varble4u

I bought the parkflyer.com 182 with the standard NiMh cells, I was getting 5 minute flights (brushed motor). I then bought their 2s lipo upgrade with 1C charger and then got 10 minute flights. Next I went out and got the Mega 16/15/7 motor, Jeti advance 18 speed controller APC 7-5e prop and Kokam Cellpro 2000 mah, 15 c discharge LiPo. On my bench test ran the plane or 13 minutes before I heard the motor sag a bit. I checked all components and they were barely warm. I will flight test tomorrow, would going with a 3s pack give me more speed? Also thinking about trying the APC 8-4 or 8-5 e prop as the 7-5e prop does not seem to load down the motor much. Any suggestions? Also trying to find the Cellpro 4S charger but after doing a web search , see that it will not be out until late Jan. Any suggestions for an alternate charger, I really wanted the Cellpro 4s with balancer since I am going with the Kokams with taps.
Also I can program my controller for voltage cutoff, my two choices are 3.0 and 2.7 volts per cell. Should I stay with the more conservative 3.0 volts or could I go to 2.7 per cell without damaging the pack. Thanks in advance, this electric stuff is fun. Ken