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Re: [Land-speed] Book on Weather

To: Dave Dahlgren <ddahlgren@snet.net>
Subject: Re: [Land-speed] Book on Weather
From: drmayf <drmayf@mayfco.com>
Date: Thu, 15 Jan 2009 12:13:44 -0800
Hmmm...I don't mess with humidity because I do  not go fast enough to 
worry about the last erg of energy from the motor. Either I am too smart 
to worry about it or too dumb. I suspect the latter. So I need some 
tutoring here. Lemme see, one would need to determine the grains of 
water in the air at the temp and pressure where the motor is. Then 
because water vapor displaces air then the number of grains of air would 
be displaced from any particular volume of air. So with a lessened 
amount of  air and hence less oxygen to burn with the fuel then hp would 
be down. So how much would that actually be? I don't have the tools to 
figure this our. Ie how much humidity is present at B'ville on a typical 
95 degree day at a baro pressure of 12.5 psia.  Then  how many grains of 
water would that be? I could work it out from there... No my efi doesn't 
take into account water vapor automatically but I could change the fuel 
table a smidge to account for it.  Anybody on the list actually tune 
accounting for water vapor when on the salt? Just curious...

mayf
Dave Dahlgren wrote:

> Going from 0 to 100% humdity there is +- 2% correction.. I can promise 
> you after 30 years on a dyno tuning engines if I dial in +-2% fuel 
> there only a way too far to the right of the decimal point change in 
> HP... i dare you to find Holley jets better than 1%..LOL
> Dave
> ----- Original Message ----- From: "Joe Timney" <joetimney@dol.net>
> To: "LAND SPEED LIST" <land-speed@autox.team.net>
> Sent: Thursday, January 15, 2009 1:54 PM
> Subject: [Land-speed] Book on Weather
>
>
>> Patrick Hale (www.dragracingpro.com <http://www.dragracingpro.com>) has
>> a new book out on weather. John Beckett and I used Patrich's
>> BonnevillePro program with great success from '99 thru 2001 so I bought
>> the book before Christmas. As far as I'm concerned, Patrick has another
>> winner. He covers all aspects of weather, with great definitions.
>> Included is a good comparison on Barometers, more of what to stay away
>> from. The book is written on drag racing but weather is, well, just
>> weather!!! Definitely for the techno-geek!!!
>>
>> When it comes to weather, I really like my Kestral 4000 Weather Station.
>> I own about $800 worth the weather instruments from my drag racing days
>> but the little box gives me more info, a lot easier and has a running
>> one month memory. Kestral has a new model, the 4250, which includes
>> Grams of Water.
>>
>> Hope this helps,
>> joe
>
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