Ok, so you lose some horsepower from the flywheel to the wheels? Where do you lose it at (what takes it away) or is it just measured differently? Is there anyway to get some of it back? And when your Turbo builds up PSI... Where is the PSI being measured at? Thanks guys!! (Just questions I've been wondering for awhile about)

 

The flywheel is a rating (usually unbacked, from the factory) of horsepower which the engine makes without the drivetrain attached. There is typically a 20-25% power loss through the tranny (moving parts are susceptible to friction etc.) and which is measured at the wheels using a dyno. So they are measurements of the same thing, simply at different "stages".

About the turbo, I'm pretty sure that the pressure is measured at the turbo manifold, though I could be wrong.