Hey, I have read alot about you lightening guys dynoing your trucks and everyonce in a while someone not seeing the Numbers they expected.

Not sure if it applies to your trucks but interesting just the same. Artical from Car and Driver about dyno and cool winds through the front off the truck.

Sled...

 

Sorry, forgot the link. Here it is.

http://www.caranddriver.com/article....&page_number=1

Sled...

 

Same car, same day, same dyno and almost a 100 horsepower difference...interesting to say the least. I'm not real sure that Ford is up to par with BMW as far as onboard computers go though.

 

well generally when you go to a dno they have one or two huge fans blowing air through the radiator and heat exchanger.

This isn't accurate though, as the force of air never changes and remains constant, so at low RPM's the air is flowing at 100mph (example) and at 6000 rpm's the air is still flowing at the same 100mph.
so the cooling is better on the low R's and worse on the high R's.

Also,Gregg Evans is the transmission guru and calculate the efficency of the drivetrain. I forgot how much loss is due to the transmission.
I'm not sure if it takes into account the parasitic loss from spining the A/C, power steering and of course the eaton at higher R's/

Also I know that the faster the Eaton spins:
1. the more power you make
2. the more power it takes to spin it faster
3. the more heat it creates

so #1 must be greater than the loss caused by #2 and #3.
to spin an Eaton at high RPM"s I've read can take a considerable amount of HP. I forgot the number but it was shockingly high.
(I want to say around 60hp, but it was a long time ago that I read that could be way off, I just remember it was high)