Ok, everyone...I had the absolute pleasure of meeting Len in his shop on Sat. afternoon. I do not have enough time to type the accolades, but suffice it to say that Macrotech as a shop and Len as the leader of the pack, are without a doubt, the finest pro-shop I have ever seen in my life!
Every tune-up tool and gizmo know to modern man.
The level of professionalism is first class.
If Len and the people at Macrotech can' t fix or tune it, it can' t be done!
If you need to drive an hour+ to get there...go.
I would gladly make the trip. In a word...Unbelieveable!

But back to the original question...." What I learned Saturday about bow effeciency"
The short version goes like this: For each pound of bow draw weight, you should get 1 pound of kenetic energy. This would be your end result, in a perfect world, if all your components are perfectly matched, etc.

Using my bow as an example: 386gr arrow @252=54# K.E. off of a 63# bow= 85% efficiency.

So to increase my bow efficiency it appears as though I would have to tweek my arrow weight:speed ratio so as to affect my KE number to get it higher. Right?