Horsepower % lost

[tholyoak]

This 15% number is always thrown around.

Let's think about it for a second. If I have a 100hp car with a 15% drive train loss. That means 15hp is lost to the rotation of components between the flywheel and the tires (friction heat etc), fine. Now I take the same car and drop in a 300hp engine, by this flat 15% loss method the components between the flywheel somehow now consume 45hp. Doesn't make much sense does it. I am open to suggestions as to how this is but it seems to me that the parasitic loss from the flywheel should be constant for a particular car and not a function of the amount of horsepower being produced.

My take is that the trend of comparing runs on different dynos is worthless, also trying to extract accurate flywheel hp numbers from chassis dyno numbers is also a pointless pursuit.

Todd