Originally Posted by Red__Zed

Cmike, I honestly can't tell if you are just messing with me. If you are, please disregard the following (and insert joke about NYC schools)


OK. Let's talk through this slowly.
Let's say you have a car with 100HP at the crank.

If there is a 20% drivetrain throughout, you will have 80HP at the wheels, because:

drivetrain throughput = 1- drivetrain loss = .8

100*.8=80

Are we tracking this far?


Now, we want to calculate BHP from WHP. To use the same numbers, we have 80HP at the wheels. We know we have an equation that looks like this:

80*Y=X

Where:
X= BHP
and Y = 1/(drivetrain throughput)

How do we get this Y?
Well, from our first equation, we have:
100*(drivetrain througput) = 80

Or

X*(drivetrain throughput)= 80

Or:

80/(drivetrain throughput) = X

Which is of course:

80*Y = X

To get Y, we take

1/.8 == 1.25