I had my bike dynoed by the same shop after fitting TDs and again after fitting my Supermegs 2-into-1. I lost 1HP and gained 4TQ, but those are the top numbers. Engine is an S&S 107". What I gained in the mid-range was up to 15% more torque, plus the bike is much smoother running and a greatly improved ride. No going back for me! Sound? What sound - feel the smooooth torque!