There was a post about energy and draw posted last week, Rangeball started it. Take a look and it will help out, there was a lot of good info there. If you are still concerned about penetration, which you probably don't need to be, try going with a cut on contact broadhead or even heavier arrows. I know some will debate the heavier arrows, but few will debate the broadhead selection. Something like a Magnus Stinger or similar would help out. If your distance is known and close, like from a treestand, you really have nothing to worry about and your current setup will work just fine. Make sure your broadhead tipped arrows fly exactly where you aim and you should be fine.
Have fun,
JMAC