how does humidity affect an efi motor

[dallas]

i just got my 500 hp super charged with a m3 pro charger. first time out me and my son ran about 94 mph at 5600 rpm it was about 72 out. now about 2 weeks later it has gotton warmer about 85 and the humidity is a little high and we lost about 400 rpm and about 5 mph. is this normal or should i be looking at somr thing else? thanks

[XLGPP]

It is very normal. air is much more dense. We are at 4200ft here, but in mid-summer (100+degrees) and monsoon season, while humid, the air density makes it equal to aprox 6500ft elevation. I dont know all the terminology but if you know any pilot, he could tell you all the logistics of it and how much hp you lose. I have a 500hp with whipple and I typically lose 500-600rpm between 70degrees in early spring and 100+ in summer.

[Donnie]

The best way that I have heard it told is this...How does it affect you eek!
We don't have much humidity in Phx but the heat sure does zap the life out of the motor, about 5 mph for me frown

[Robbie Racer]

High humidity, high temps and low barometric pressure will all sap horsepower. While at Lake Shasta last week, the temperatures were only in the mid 80's to low 90's, but the humidity was over 50% and the low barometric pressure combined to give us a corrected air density reading of around 4,000' on the weather computer. R/R