From my few personal bows ranging between 50lbs to more than 80lbs over the last +/-15 years I've found that they typically ranged from 2.0 to 2.5FPS/LB........my current Bengal, between 60 - 68lbs, worked out to 2.47fps/lb.
Originally Posted by cyclepath
Each bow and it's efficiency within a weight range, the arrow weight and various set-ups would be different to some extent........just like IBO ratings are different between bows for same draw weight, so would this loss or gain (to a much lesser degree).
This reminded me of a book I have from about 1990 called Balanced Bowhunting by Dave Holt. In it talks of improving trajectory and one of the things mentioned is draw weight, where he states "Arrow speed will increase approximately 1 3/4 FPS for each pound of draw weight that is added".
His example is discussing an old round wheel bow set at 55 lbs, shooting a 620gr arrow at 170fps. Bow efficiencies have improved a bit since then.
2009 Martin Bengal M2 Pro Cam w/factory STS & CCS.....66lbs, 29" DL, 422gr @ 272fps, Winners Choice string/cable, Trophy Taker drop-away Rest, Scott Release
1996 Martin Firecat XRG Pro Series w/Ultra Sonic wheels.....69lbs, 29" DL, 465gr @ 245fps, w/fingers & Martin leather glove