I can only post what's been published, if it's incorrect it's not my fault. I posted a formula earlier what's been listed in how to calculate rear wheel horsepower, I can't be responsible if they don't show all of the different variables.
If you really want to learn, you should find a shop local to you with a wheel dyno and go watch them run it. Hand around, grab a broom and sweep up. Make yourself fit in. Most people will teach those who want to learn if they aren’t jack asses.
I don’t know why you couldn’t do the same for an engine dyno.
It’s great to read and learn, but eventually you have to get out there and start testing what you think you know before posting off the wall stuff.