Dave,
The numbers are approximated based off of dyno results of a friend's truck, one which is not setup quite as well as mine. He pulled about 480 HP / 960 ft-lbs on a recent dyno day. I have better air/exhaust setup than him and run a higher output program, thus I'm nudging his numbers up just slightly for my estimate. I was hoping to hit a dyno this past weekend, but that didn't happen.
I can't shift fast enough for a 0-60 like that, and don't have access to 500 HP throughout the RPM range, obviously. My buddy's truck is quicker than mine, since he has an auto, his shifts are quicker and his turbo stays spooled more between shifts. I'd need about 200 HP more than I have today in order to make up for gearbox lag... more for the extra torque than the horsepower, though.
The high power isn't there for FE, obviously. It's only there to have fun. It's rarely enabled, otherwise I'd get myself into trouble.
The UG is just one of the tools in my box now to help push my FE higher, and to gain a better appreciation for what changes make to the big picture. I never expected the HP/Torque numbers it shows to be reasonable, I just thought it was interesting that it thought I was making 505.6 ft-lbs at 0.38% engine load at idle.
Hopefully after a few weeks/months using UG I'll be in a better place with it all.