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E-fan airflow estimation

Posted By: mrob

E-fan airflow estimation - 05/11/21 02:40 PM

Hi,
I recently installed a Derale shrouded e-fan (P/N 16831) in my 73 Cuda. Derale did not provide fan curves for the fans, so I reached out to the fan manufacturer (a company named FAZ) and they gave me the fan curve data. The fan curve data includes the CFM, resistance (in. H2O) and amperage starting at 0 resistance up to 1.0 in. H2O.
So this got me thinking: If I can measure the amperage draw of a fan motor, can I work backwards and use the manufacturer's data to estimate the resistance at that data point? Here's an example of one data point:

CFM: 1,010, resistance: 0.4 in. H2O, amp draw: 13.6A

So let's say that I measure 13.6A while the fan is running (not start up amperage), could I estimate the resistance through my radiator core at around 0.4 in. H2O and the airflow for that fan at 1,010 cfm?

I'm trying to get some real world numbers instead of the inflated numbers claimed by the companies.
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