I am planning a move from Vegas( average humidity of 10%) to Shreveport, LA( average humidity 60-70%).....It will be a huge drop in elevation( like 2000 foot drop from 2200ft to 125 ft.) but I am uncertain how the increase in humidity will affect horsepower and track times, if at all.

 

You'll notice a big increase in power just from the altitude drop. Humidity will affect performance but it's not a very big factor.

The percentage of humidity means nothing. Dew point is more accurate since it's a better indication of how much moisture is in the air. There is more moisture in the air at 50% humidity and 80F than there is at 50% humidity at 60F because of saturation pressure. Warm air can hold more moisture.

Moisture in the air displaces the air molecules. When the engine tries to burn air, it's also burning the added moisture. Power will be down slightly because of less air molecules to burn.

During a race day the humidity can start out in the morning at 70%. By mid day it may drop to 30% in the heat of the day. In the evening it's back up to 70%. This may look like a big change but the percentage change was mostly because of the temperature change. If the dew point is also tracked you can see that it changes very little all day meaning the total amount of moisture in the air never really changed.

 

There are at least 2 good tracks around there. Red River is supposed to be a very good track, but I've never been there. And Hallsville Raceway in Texas has a very good track, but the pits aren't the greatest.

 

There is an environmental correction program on the Bowling/Grippo site:

BOWLING/GRIPPO AUTO CALCS

If you take a typical 13-sec car, running at 70degF, and vary the relative humidity from 0-100%, the maximum effect on ET calculates to a shade under 1/10th second. That will give you some idea of the relative importance of humidity on ET - Stephen explains it very well.

On the other hand, the 2,000' reduction in altitude should be worth 3/10th's..... so you are well ahead......

 

2000 foot drop I can only dream about. Most race days the density altitude here is over 5000 feet. Theoretically at sea level I should run 10.8. Maybe some day I'll get to Mission BC. When the air is really good there the density altitude can go below sea level.

 

LVZ2881---

you might already know this, but if not hope this helps, if you go to LS1.com; to the Louisiana Section, they can prob help you out on the area.. I believe most of the Thunder Racing guys talk there...

93Z Will

 

Thanks for the replys guys...much appreciated.

I am really looking forward tothe altitude drop myself..here in vegas the density altitude on a race night averages 4500-5500 here as well.


based on what i have read, on good night at RRR, i can plan on a rough drop of 3 tenths from a 13.6 to a 13.3.....I can handle that!!

I think I can also live a tenth variance based on humidity as well.


and yes, I have been going to the Louisiana section on LS1....

thanks again guys.