Once you eat your cake, it's down in your stomach where you can't see it anymore, sorry. However, that's given that you don't crank up your draw weight or make any cam changes. Obviously if you turn up the poundage you gain both speed and KE. However yet again, you don't want to make the bow so hard todraw that you are unable to do it under less than ideal conditions (like when you're hunting, are cold, got layers on making it harder to draw, muscles aren't warmed up) jfyi I draw 70 easily indoors but shoot 60 in the woods.

Read this info I found when faced with the same question a while back
http://www.huntersfriend.com/arrowhelp/arrow-selection-5.htm


And here is a KE calculator
http://www.goldtip.com/calculators/kinetic.asp

Honestly, 50 foot pounds is said to be enough to take elk. With that in mind, I think your efforts would be better spent at the range. With 50 lbs KE or more, it's all about shot placement. I'm sure there are guys who shoot an 80 lb bow and can't always blow through the shoulder blades.