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post #1 of 14 (permalink) Old 04-01-2003, 12:56 AM Thread Starter
 
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CFM for my car

I have a performance shop who wants to do a killer prototype intake for my 3.2L 01 ES.......the guy asked me what the CFM was for my car and I have no idea......does anyone know what the number is or how to find it?

So far I have sent an email to my dealership and posted to this board.

Last edited by Spooky; 04-01-2003 at 01:33 AM.
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post #2 of 14 (permalink) Old 04-01-2003, 12:57 AM
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Dont you mean the CFM?
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post #3 of 14 (permalink) Old 04-01-2003, 12:59 AM Thread Starter
 
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oops.....past my bedtime...forgot how to type:blush:
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post #4 of 14 (permalink) Old 04-01-2003, 01:03 AM
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The CFM rating is the flow amount through a given medium. CFM stands for Cubic Feet per Minute, and so, he is wondering how much air flows through there per minute. The only way I know of is to flow bench test, but that is very expensive and would cost a lot more than an efficient intake.
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post #5 of 14 (permalink) Old 04-01-2003, 01:32 AM
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Should be listed somewhere. From the details you said you came up with my buddy there, sounds like a wicked crazy design. Let me know how much he quotes ya on an exhaust when you go that route.
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post #6 of 14 (permalink) Old 04-01-2003, 01:35 AM Thread Starter
 
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will do man....although I am still leaning towards giving my car to Brullen Exhaust for a few days and let them fabricate a system for my car...that way the template is made and anyone can get the same system bolt on....you know take one for the team kind of thing.....
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post #7 of 14 (permalink) Old 04-01-2003, 01:48 AM
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First, a 3.2 is 195 Cubic inches in displacement.
With a 6500 redline and 100% Volumetric Efficiency the engine would flow about 366 CFM.
In reality the 3.2's Volumetric Efficiency is around 80-85% in those respects you only flow about 300 cfm.
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post #8 of 14 (permalink) Old 04-01-2003, 02:02 AM Thread Starter
 
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so to get the CFM, it is just a formula then?
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post #9 of 14 (permalink) Old 04-01-2003, 03:48 AM
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so you finally went to that shop
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post #10 of 14 (permalink) Old 04-01-2003, 04:18 AM Thread Starter
 
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oh ya.....killer system he is gonna do for me.......can't wait....I will look for you on MSN and tell you about it......
unless EDF talks to you first hehe.......:bigsmile:
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post #11 of 14 (permalink) Old 04-02-2003, 12:09 AM
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Re: CFM

Actually, it would be half of those numbers. There's 1 intake stroke for 2 crank revolutions, (4 stroke), so about 150 CFM.

>First, a 3.2 is 195 Cubic inches in displacement.
With a 6500 redline and 100% Volumetric Efficiency the engine would flow about 366 CFM.
In reality the 3.2's Volumetric Efficiency is around 80-85% in those respects you only flow about 300 cfm.
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post #12 of 14 (permalink) Old 04-02-2003, 05:25 PM
 
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Quote:
Originally posted by wire2
Re: CFM

Actually, it would be half of those numbers. There's 1 intake stroke for 2 crank revolutions, (4 stroke), so about 150 CFM.
I believe FunkRider is actually correct:

displacement=3.2L

At 6500 RPM, there are 3250 intake strokes per minute

So, 3250*3.2L=10,400 liters/minute

This converts to 367 CFM.

Like FunkRider said, that doesn't account for volumetric efficiency (the ratio of air mass actually drawn into a cylinder to the mass it would hold at atmospheric pressure). If someone can privide dimensions for intake valve lift, diameter, etc, we could calculate the Mach index for the valves and see how choked the flow is. I would guess, as did FunkRider, that the volumetric efficiency is actually around 80% (or possibly higher, if there are 2 intake valves), which would indeed make it closer to 295 CFM.

If you design for around, say 330 CFM (90% vol eff), you might be a little on the conservative side, but that's a good thing in this case.
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post #13 of 14 (permalink) Old 04-02-2003, 11:49 PM
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White97sport, you're right. I stand corrected.
I suspect I fatfingered the calculator.
Funkrider, no more second guesses from me.
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post #14 of 14 (permalink) Old 04-03-2003, 01:19 PM
 
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Quote:
Originally posted by wire2
I suspect I fatfingered the calculator.
Heh. I do that quite often, usually because of all the caffeine, tho... :crazy:
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