My experience has been that for non-altitude adjusted tracks, it’s not at all uncommon to have the performance calculators show 5-15% lower power than stp hp from the dyno.
You have the combination of the parasitic losses that are incurred by running the transmission, converter, etc, along with how much the weather at the time differs from a “standard” day.
For altitude adjusted tracks, the difference will obviously be even greater.
In theory, the performance calculator is showing the in car/at the track power for that moment in time.
Keep in mind, the poorer the car set up is, the greater the difference you’ll see between the stp dyno hp and the performance calculator.
I have a few customers who run at fast tracks in good air where the stp dyno hp and the performance calculators are very very close.
Is that enough steam to push a 3000# A body to mid/low 9s?
Using the Moroso calculator, 10% off 790, at 3000lbs is about a 9.25
