Well.......my friends motor, which I have had on the dyno at least 25 times through the years, makes a little less than 500 std corrected hp(hp corrected to 29.92 baro, 60deg, 0 humidity), and even in pretty hot, humid, summer air, at the east coast tracks it will run enough speed to show 500hp on the Moroso slide rule.

I'm pretty sure his car isn't so good it would also make 500rwhp........ so, from my perspective......it's engine hp.