After some decent searching all I could find:

Per Sharif:
http://my350z.com/forum/4067798-post91.html
Does anyone have confirmation on the CFM ratings of the stock fans?

Thanks

 

why cant u just take Sam's word? The stock fans are small so I wouldn't expect it to cool that much.

 

If a crackdealer (or partsdealer to be more precise) says he's got some good sht, I'd be hesitant to listen because he is the one trying to sell it to me.

 

If u really want to know the exact CFM then why not go to your local dealer to find out?

Why is this even in the FI section?

 

I'm not so certain to take the word of a performance shop let alone a dealership.. Have you met most of the people at dealerships? I think mentioning CFM would instantly lead to


It is in FI because who the hell else would care to know this?

By the way- after some google searches, I found something interesting. The High CFM rating on a stock 1998 altima is 1500CFM. Sam's mentioning/Sharif's mentioning doesn't seem that comforting.

 

Stan, maybe Chris knows?

 

I've asked him before, he didn't know.

 

They're only for when your idle- why does it even really matter.

 

Even with my simple "stick my hand out" test method, which is slightly more scientific than the "butt" dyno...I can assure you that the aftermarket fans pull more air. Each Spal fan we use has 1710 cfm worth of airflow...and we are using two of them. And the steady state results we saw on the dyno, seem to show they are doing a great job of keeping things cooler.

 

Would the aftermarket Spal fans work on the stock radiator work just as well as just a aftermarket radiator like AMS? I need to maximize the room up front.

 

Airflow is airflow so yes they would work the same on the oem radiator. The problem becomes the limit of thin oem radiator.

 

Once you have exceeded approximately 30-40 mph the fans become irrelevant, period. The fans function is to flow air through the radiator fins, that's it. This is useful and needed in slow traffic and when the car is at or near a stand still. Once the car is moving at a steady pace the fans become useless since the car is generating its own air flow through the radiator fins through the opening in the grill.

So in theory once the car is moving and generating its own steady air flow the fans then actually become more of a hindrance in air flow since the air would actually be more obstructed by a fan and it not being able to keep up with the increased air flow rate, if there was nothing there at all (fans) to obstruct the air flow then the cooling system would be even more efficient once the car reached a certain speed.

Fans obviously are needed on a car, that's for sure. But it is foolish IMO to spend any money on a mod like what those shops are trying to push on people.... the placebo effect comes to mind, LOL Plus not to mention all the problems with the relays and such those things have always had, what a joke. Save your money for mods that work like a larger capacity radiator or a lower temp thermostat, etc.

 

BINGO, we have a winner You sir are on the right track. Especially the shops pushing this mod. It's also like the Nissan Pathfinder coolant bypass mod that doesn't work but it too is a gimmick to try to sell someone on. LMAO. People can be sold anything by the right salesmen.

 

The fans help a lot here in Phoenix in the summer when you are in traffic. But I would consider a good oil cooler before a big fan upgrade.

 

^^^ in traffic i'd rather have hi flow fans. oil cooler isnt going to help anything sittting still.