% of power lost in drivetrain

Wicked complicated subject, but it's not exactly as easy as putting a horsepower number on it or even a percentage. Now I'm only guessing but I would start with how much the internals weigh and how much drag the trans fluid puts on the components at every rpm ( drag goes up as speed increases )..... ok so it would be easier to dyno the motor then slang it in a car and dyno again to see.... at least it would make my head hurt less :)
All I know is that a non-lockup converter will always be slipping and thus always be gobbling up power, and after swapping to a 4-speed, the slant "feels" much more peppy :)
SO.. does anyone have engine dyno vs chassis dyno results??