Originally Posted by Doc
I don't think there really can be a standard curve/straight line because there are too many variables. You've got torsional elasticity of all the various materials, frictional resistances which are a combination of efficiency of design, component tolerances, assembly tolerances, fluid viscosity, and then temperatures messing with all of that.
I've always heard that as a ball-park average you can generally assume around a 15-20% loss percentage but I've noticed in the last few years as computerized processes and synthetics have improved things that percentage has dropped to around 12-15%. For a Camaro assume 12-13% with the drivetrain completely stock.
Interesting. In my personal example above if you take the 22% increase of power as the right new crank HP number of 520 then the drivetrain loss is 520 -461= 59 which equates to a percentage of 12.8%. Again this is for a manual tranny. I would think a torque converter style auto would be a little higher.