how to find or calculate density altitude ...
 

Is there an instrument or way to calculate density altitude when at the track that doesn't require one of these $$$ weather stations? I like to keep accurate records of my runs including weather conditions and would like to add in DA but don't know how to find or calculate it. I really don't want to spend $500+ on a weather station or predictor although the ones I've seen at the track are very, very nice. It is a FI car so I'll have my laptop with me so if they have wireless there I may be able to pick that up if it helps.

Thanks.

Re: how to find or calculate density altitude ...
 

If you happen to already have a Porta Tree, you can add a weather station for a couple of hundred bucks...

Or if you are like me, and just wanted a really good reason to buy one, other than just practicing your reaction times, getting one with a weather station sealed the deal.

David
The New Hemi Guy

Re: how to find or calculate density altitude ...
 

Try this site http://www.dragtimes.com/drag-racing...tors-tools.php

Re: how to find or calculate density altitude ...
 

Yes. You can google the calculations. I believe you'll also need to calculate pressure altitude.
Or -- pickup a Kestrel 4250 for $259 if all you want is DA.

http://cgi.ebay.com/Kestrel-4250--Ra...22161002r14155

Re: how to find or calculate density altitude ...
 

If you a an iPod phone, there is an application for it:

http://itunes.apple.com/us/app/densi...313097113?mt=8

or

DA= 145442.16 X [ 1- (17.326 x Pa) / Tr ] 0.235

where:
* DA* = density altitude, feet
* Pa = actual pressure (station pressure), inches Hg
* Tr = temperature, deg R (deg F + 459.67)

Re: how to find or calculate density altitude ...
 

Go to a aircraft surplus and get an Altimeter with a barometer window, less than $100 and dam close. Seen them in tool boxes everywhere, some folks dont know what they are looking at.

Re: how to find or calculate density altitude ...
 

Would this work?
http://www.campmor.com/outdoor/gear/Product___89661

Re: how to find or calculate density altitude ...
 

another one.
http://www.campmor.com/outdoor/gear/Product___85329

Re: how to find or calculate density altitude ...
 

Another tool is the Hot Rod Calc which was designed by Calculated Industries and advertised on the NHRA.com homepage. It's a hand-held calculator which has pre-programmed automotive formulas that were designed for drag racers. I've found it useful to calculate basic ET predictions and horsepower estimates. It's now available from Mr. Gasket as Model 8703 for $79.95.

Re: how to find or calculate density altitude ...