here: http://www.aaroncake.net/rx-7/efanmyth.htm

(sorry I don't know how to make it a link directly but you can handle that I'm sure!)

The article discusses the "myth" of e-fans. The author is working on Mazda's but the write up is generic. He discusses hp issues, cooling, electric draw from the system etc.

I have been thinking about getting a set of fans, but I wanted to do some research first.

Interested in opinions and analysis of the article and any first hand experience.

Thanks.

 

He can crunch his numbers 'til he's blue in the face, but Cooler (or was it 'Icoolum??) was involved in the R&D done on the FAL kits for the F-150. They ran the truck on a dyno with the OEM mechanical fan, swapped the FAL kit in place of the mechanical fan, and re-ran it. IIRC, they did the runs back-to-back (or as close as reasonable on a hot engine) without even un-strapping it from the dyno. They measured an actual change of 11-17 hp over stock. I don't think you can measure the difference any more analytically than that.

He's also neglected another critical advantage of electric fans: By reducing rotating mass, the engine can rev more freely. Less rotating mass = less parasitic loss, plain and simple. The additional load borne by the electrical system does not even come close to the parasitic loss caused by the mechanical fan.

-Joe

 

Amen

 

According to the article a 'clutch fan' only is engaged when needed, during idle or while moving very slowly. Both cases use very little hp, so I'm wondering where the xtra hp comes from w/ e-fans.

As far as a parasitic loss from the rotating mass, if it is not connected to the engine while at high speed or when it is cool enough, then where is the loss? Do we have any actual reports or data etc. available to show the actual hp required to spin the fan and when it is actually a load on the engine?

I am interested in hearing more about the test that FAL did. Anyone have a copy of that?

Thanks again for you insight and experience.

 

i don't believe what that guy has to say on that site.i know in my f150 the fan was always spinning and when the fan was engaged it would spin faster. i have the edge evo on my truck and i adjusted my idle up on my truck. well,few weeks later i installed my efan not changing any setting. my idle went from about 1200 to 2000 and in order to keep my truck from wanting to take off when i'm stopped i had to put my idle back to the factory setting. i also know another guy who has had the same thing happen to him when he installed his. if power is such an issue, get a bigger alternator then that issue will be dead.

 

Just remembered: It was Tom in Tacoma.... Haven't seen him around here in a while.

If you have doubts, e-mail Mike Troyer... he had some fascinating facts when I e-mailed him about it a few months back.... I never posted his replies, although I had his blessings to do so. I'll dig 'em out of my e-mail if I get a chance at work tomorrow...

-Joe