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pjaneiro pjaneiro is offline
Senior Member


2002 Chevy TrailBlazer LT
Forest Green Metallic 4.2L I6 4X4
Join Date: Feb 2007
Location: Montreal, Quebec, CANADA
Posts: 882
Well i had some fun yesterday

I needed some toys at my local pro hardware store, and there was a demo all day long of a company selling paint booths aerators, the guy was showing off their new fan designs and comparing them to the competition with some meters and other gizmos, anyhow, he had a box where he would put the fan cases and it would calculate the cfm produced by each fans that was attached to the air box

guess what i did ? ;-)

I brought all the rad fans i had in my possession

LS1 kit
LT1 Kit
A 1999 Dodge stratus Kit
1996 Ford Taurus Fan

Well the guy looked at me funny, but he agreed, after a 50$ in his pocket. but you know what...i just wanted to put my mind to rest so here are the numbers

First off they were ALL tested at Battery voltage (12.5v)
first and then with my truck running with a 30ft 4 gauge wire from my battery 14.5v

Not the exact numbers they fluctuate from 150 to 250 cfm this is an average

Battery operated

LS1 FAN SHROUD
1 fan turned on - 4800 cfm
2 fans on - 9500cfm

LT1 FAN SHROUD
1 fan turned on - 5000 cfm
2 fans on - 8700 cfm

Dodge Fan (both fans are always on - 2 speed)
Slow speed - 3700 cfm
High Speed 9000 cfm

Ford Taurus (1 fan two speed)
Slow speed - 2800 CFM
High speed - 5600 CFM



Alternator Powered

LS1 FAN SHROUD
1 fan turned on - 5100 cfm
2 fans on - 10500cfm

LT1 FAN SHROUD
1 fan turned on - 5200 cfm
2 fans on - 9500 cfm

Dodge Fan (both fans are always on - 2 speed)
Slow speed - 4200 cfm
High Speed 10400 cfm

Ford Taurus (1 fan two speed)
Slow speed - 3200 CFM
High speed - 6000 CFM



So keep in mind not all fan are made the same, you can have different numbers if you have a motor that is more used than the other

so the conclusion here is that ls1/lt1 fans produce around 10000 cfm when both motors are on

they pull the same numbers compared to the stock fan that produce 10000 cfm at 3000rpm from what i have read


So I must wonder now

i did not have a clutch fan to test out the cfm of it operating, but i do see the numbers he posted earlier, and the electric fans are about the same to his...

BTW the way the guy selling the booth fans was not nuch impressed...

his electric fans 13.5" diameter (operating on 120v) actually pushed out 17000 cfms... and could slice a celery , his way fo showing that the blades were slicing air or something...the ls1/lt1 fans were not able to slice a celery but mostly just crush it or just stop the blades....lol

i had to try...