Technical Questions and Discussions

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CFM

Printed From: West Coast Fieros
Category: Technical Topics Forum
Forum Name: Technical Questions and Discussions
Forum Description: Got a technical question about your fiero? ask it here.
URL: http://www.westcoastfieros.com/forum/forum_posts.asp?TID=1801
Printed Date: 24 April 2025 at 10:39am
Software Version: Web Wiz Forums 12.01 - http://www.webwizforums.com

Topic: CFM

Posted By: danht
Subject: CFM
Date Posted: 06 April 2010 at 1:47pm

does any one know of a formula for figuring Cubic feet per minute using diamater of a venturi or throttle valve plate?

Replies:

Posted By: Dr.Fiero
Date Posted: 07 April 2010 at 7:08am

http://www.efunda.com/formulae/fluids/venturi_flowmeter.cfm - http://www.efunda.com/formulae/fluids/venturi_flowmeter.cfm

That's through a venturi (which gets weird).

You're almost better off to just figure out the difference in flow if you want to hog out a throttle body (which has almost no venturi effect when you're looking at EFI vs. Carb).

Posted By: danht
Date Posted: 07 April 2010 at 1:34pm

I guess that was what I was thinking. that the throttle plate is the only unchangable part, where as the body can be massaged to a larger diamater.

I have a spare intake for the duke and wanted to play with my dremmel. I havn't taken a mic to one but understand that the later duke TBI's had a larger diamater. (since the Holley TBI's for the dukes seem to be gold)

every little bit.

Posted By: Dr.Fiero
Date Posted: 07 April 2010 at 1:38pm

WTF - go nuts on the thing, and turn it into a dry throttle body, then rig up an MPFI setup (which is what all the later setups are - like what's on the 2.2L in my Cavalier).