From:Tim Roller>magnum318@bewellnet.com
>Well I'm not too smart, being from the SOUTH and born in the back country
of Arkansas, but it would seem to me that if you take measurements of the
throttle blades and measurements of a stock TB bore at the top inside and
take these measurements and call up HOLLEY carburaters and give them the
measurements, considering they still make 2-barrel carbs they might give you
the CFM ratings and we can go from there on the boring out and come up with
a close equivilient CFM measurement. It's at least worth a shot.
-----Original Message-----
From: Mike Miller <slepyhed@netway.com>
To: dakota-truck@buffnet.net <dakota-truck@buffnet.net>
Date: Friday, July 17, 1998 9:28 PM
Subject: Re: DML: Throttle Body Mods, Theory
>
>----------
>> From: Boog318@aol.com
>> To: dakota-truck@buffnet.net
>> Subject: Re: DML: Throttle Body Mods, Theory
>> Date: Friday, July 17, 1998 10:24 PM
>>
>> I agree with your theory Mike, but I took "calculus for non math majors"
>in
>> college so I never had to derive my own equations. Now I wish I did. Oh
>> well. Your theory seems correct if your temp and humidity stays
>constant.
>> What constant values did you use anyway?(too lazy and too far out of
>college
>> to derive) You might think of putting a thermometer inline with your TB
>to
>> measure more exact incoming air temps. Id say put a barometer in there
>too
>> but......:) The thermometer would compensate for engine temps
>contributing to
>> overall air temperature, thus eliminating a variable. Someone on the DML
>had
>> a TB thermometer set-up, maybe they will see this and get back to you.
>> Boog
>
>Yes, I read about the temperature sensor that someone managed to rig up.
>I'm not expecting the weather to change all that much here in New England
>over the next two months or so. That really isn't a significant variable, I
>don't think. From July to august, we can pretty much count on "hazy, hot
>and humid" weather. Ask any Boston meteorologist. They'll tell you they're
>sick of repeating that phrase.
>
>When it comes to the constant values you mentioned, I'm assuming you want
>to know what I was using for air density, pressure drop across the throttle
>body, throttle body length, etc. Well, as it turns out, I didn't have to
>decide on a value for any of these, since algebraically, these terms merely
>cancel out.
>
>Also note that I am not claiming that a stock throttle body flows 500 CFM
>and a modified one will flow 600 CFM. The 500 CFM statement is only a
>shot-in-the-dark guess, to be used as an example only. Really, I have no
>idea what the flow capacity of the throttle body is. I'm just predicting
>that the modified throttle body could flow as much as 22% more air. I could
>easily be wrong. That's why I'm doing dragstrip testing. I'm sure that
>everyone out there really only wants to know one thing: "If I port out my
>throttle body, will the truck run the 1/4 mile faster?" That's what I'm
>setting out to prove. My analysis is grossly simplified. If I turn out to
>be wrong, well, that's a valuable lesson to me as an engineer.
>
>Like I said, stay tuned...
>
>-Mike Miller
>
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