In my experience i have found that dynos often tell lies.
I beleive that it is only used for tunung and are very inconsistant in there power figures.
I have an r33gtst with I/c, 14psi standard trbo,air filter, 3inch exh turbo back.
1st dyno run @ PET: 198RWKW(14psi)
2nd dyno run @ club Meet: 170rwkw(14psi)
With these mods described above i ran a 13.8 1/4 mile.
Then
Installed Microtech plug in at PROMAZ
Dyno run @ Promaz: 165RWKW Although the car is a lot quicker then what it was with previous dyno runs.(14psi)
Hope that info can support why i think as i do about dyno power figures.