Originally Posted by Ben Diss

Whoa there big fella. I didn't mean to pi$$ all over your online calculator parade. I just asked how you calculate the effects of humidity on density altitude. I understand how moisture displaces oxygen, it's just that us pilots have never been taught that math. We consider pressure, temperature and mean sea level when we calculate density altitude. I just went back to both of my most prized textbooks and looked for some way to factor in humidity when calculating density altitude and neither Stick & Rudder, nor Aerodynamics for Naval Aviators mention it (although there is a good section on transonic flows and the compressible nature of air that would be of interest to most Vararam customers, but I digress).

So ... how does one factor in humidity when calculating density altitude?






I suggest that he remove the door skins and carpet next, but that's just me.

Originally Posted by HOXXOH

My only response to your lack of understanding is to ask what airline you work for, so I know which one to avoid. Of course, that assumes you're an aircraft pilot rather than a riverboat pilot or any other profession with the pilot job description.

Originally Posted by AirBusPilot

Relative humidity has little affect on DA, you might get a 500' swing going from 0% to 100%.

Originally Posted by AirBusPilot

...Ah gee, AirBusPilot, yer jus jelus u elitist over edyacated smert azz. Yeah, sure I am. lol I know most that have posted in this thread have seriously fast cars no matter where they run...

Originally Posted by Ben Diss

So ... how does one factor in humidity when calculating density altitude?

Originally Posted by Ben Diss

Can't imagine why this would be ...

Originally Posted by 1.8t

I don't understand what you are saying?

Since I am a Mech. Engineer, I am sure my Thermodynamics 2 book could easily find a direct relation if thats what you want, however I no longer have that in my possesion.

Originally Posted by patton

i see a pad lock coming soon..that should clear the air

Originally Posted by AirBusPilot

Relative humidity has little affect on DA, you might get a 500' swing going from 0% to 100%.

Originally Posted by Ben Diss

Can't imagine why this would be ...

Originally Posted by AirBusPilot

Relative humidity has little affect on DA, you might get a 500' swing going from 0% to 100%.

Originally Posted by HOXXOH

It's a bigger factor at higher temps than at lower ones. About a 150' difference around 50 degrees, but 1000' when 100+ degrees.


It would just be a relief to me knowing that you're not in the front seat lacking an understanding of the relationship of RH to DA, anytime I'm in the back. I guess I expect more from professionals who ferry me from place to place.

Originally Posted by AirBusPilot

Sniff, will you be ma frend Mister Dover? Oh noz, no frends. lol

Originally Posted by robz

Yeah but it can affect 1/4 mile times more significantly.

DA gives you a good indication of the power a motor will put out on a certain day, not necessarily how fast the car will run.

Originally Posted by Ben Diss

Naa, that's OK. The other pilot answered it for me. Answer is it's doesn't matter. The effect is so small that it doesn't make a difference.

Originally Posted by robz

Yeah but it can affect 1/4 mile times more significantly.

DA gives you a good indication of the power a motor will put out on a certain day, not necessarily how fast the car will run.

Originally Posted by Ben Diss

Nope. Not a bus driver. You're safe.




Awwh I'll be your friend.

Originally Posted by 1.8t

Either way, I am pretty sure this Psychometric Chart could give you your relationship. http://isites.harvard.edu/fs/docs/ic...ic%20Chart.pdf

Originally Posted by 07 Z51

I am not hurt by the science and my ego is not fragile - I do not have any dog in this fight. I read the thread for the information regarding DA and, following same, realized that you must be the most self important individual on this forum. I was just poking fun at you because you think you have the biggest brain on this forum. Might it be you that has the big, fragile ego? As point in fact, you are pompous enough to assume that I agreed with you. I respectfully suggest that you re-read my prior post, I disagreed with you but thanked you for a coherent, well thought out, detailed explanation of DA that you placed in a cocoon of crap. Go ahead, re-read my post. I conceeded nothing to you and, instead, suggested and continue to suggest that, at our power levels and set-ups, it is more the driver than the 20 additional rwhp. I speak from experience - I had a 10 second Supra Turbo (MKIII, not MKIV) from 1989 - 1994. I have had equally fast cars throughout the years and, additionally, have been frequently asked by friends and strangers to make passes in their respective cars. I am no stranger to the track/racing - at least 1000 passes since 1986 - not to mention all the stupid street racing I did when I was much younger and reckless. I have beaten "faster" cars merely because I could drive right around them.

As to my post, get over yourself. You would have found the "Uranus" comment hilarious if you were not the butt of the joke (pun intended). I'll bet you felt really good about yourself when you thumped your chest and insinuated that those that can't type and/or refuse to proofread are less intelligent than you. Someone had to point out that you were acting like a tool. I just happened to be the a$$hole to do it.

I pointed out to you that correction and DA are not the "end all, be all" of good 1/4 mile times. You have yet to dispute my assertions that it is the driver more than the rwhp (increased/decreased by DA) - in fact, you failed to address the same. And what about the transitive property? What about all of the other non DA variables? Should we ignore these because you say so? I suggest that it is all of these variables that comprise a pass down the 1320. Whether your 1320 experience is any good depends upon how well you use the hpr to pedal the car down the track.

I am willing to bet that someone with less hpr could go faster than Dennis at a track with a higher DA if the car was more purposebuilt for the 1/4. Dennis has still more room for improvement (within the external mods criteria and without adding 1 more rwhp) and does not need to rely on DA for an improvement in time if he wants to take this 1/4 quest any further.

Thanks for your explanation of DA. If you wish to take it further, please feel free to PM me.