Does anyone happen to know the airflow (in CFM) of the stock radiator fans? I am considering replacing them with an aftermarket slim-line twin fan (FAL or similar), and I need to make sure I get something equivalent or better than stock.

 

Bad idea unless you are really diligent in mounting them. You might end up with higher flow fans but they won't work as well without a good shroud, mounting and wiring...

 

Well, I don't have much of a choice; I need a slimmer fan to fit my intercooler and ductwork. I'm also having to relocate the front relay box - that's proving to be a challenge.

 

The slim ones have alot less CFM. I'll have to search and see if I still have my notes on that. Aftermarket fans = > then OEM are about 4" deep.

Well only found one sticky note. Dual 10" fans are 2200CFM
(Not shure if the above is for the slim line though)

Stock dual 11" fans 2780CFM (combined)
11&3/4" high, 12" wide (1390CFM x2)
3.7" deep
Fluidyne radiator is 14.5" tall and 24" wide.
I think the manual or parts catgalog lists them as 11.5" though.

 

Where'd the figure of 2780 CFM for the stock fans come from?

I found some 3" deep fans that look like they'd fit, that flow 4k CFM (!), but they draw 50 amps

 

Can you say "electrical fire"?

The problem with many CFM ratings done on aftermarket fans is that they are done with zero draw/resistance. Once you put a surface in front of them, their actual CFM rating plummets.

A close-fitting shroud for the fans is crucial for their efficiency. It's also the reason that the stock fan blades have a "ring" that runs the circumference of the blades.

 

Might be worth looking at other stock dual fan setups for a slimmer fan setup. I know some 240sx guys did a SERIOUS radiator and fan test, and found the dual fans from a Nissan Altima flowed a LOT of air.

Dale

 

I've read that test, whereever it was. It's one of the only fairly well-designed tests I've seen.

I'm under the impression that anything that I can get at least 2k CFM at under 20 amps should be sufficient.