Al, what you’re describing is exactly why I say it’s never a good idea to compare numbers from different dynos.

Many times it’s not a fault of the dyno at all........ but a room that’s got some strange things going on.

If a motor I test goes into a car that’s really well set up(hooks, has the right gears, good converter, no fuel system woes, etc), and it’s being raced in “decent” air, the numbers will be very close to what the Moroso chart shows.

It happens that way sometimes, but it’s the exception rather than the rule.

What I use as a general rule to see if you’re even in the ball park is 90% of the corrected hp...... in “reasonable” air(not mineshaft air).

As an example....... 800STP power, 2800lb car, DA around 2500’, temps in the 70’s.......,the number on the Moroso chart should be 720hp(800 x .90) or better(800hp would be an 8.65@155....... while 720hp would be a 9.05@149.5)
If you can’t get it to come that close(or better), there’s a good chance you might have some happy dyno numbers.

If you run at tracks high enough in elevation to use a correction factor....... then that has to be figured into the result as well.