I know how most e-fans are done - that's what I'm talking about.

And the alternator doesn't "always turn". It only turns when it's taking power from the engine thru the belt. If the engine isn't burning gas, then the alt can't turn. And JUST like removing the mech fan, if there was no alt, the engine would be able to send more power to the wheels. Why? Because the alt takes power from the engine & converts it to electrical power. And like all conversions of energy, there is a loss of energy (as heat). That's why the alt gets hotter than the surrounding air, and hotter than the bosses on the engine that it's mounted to - it's also why every alt has a fan. So now you've lost a little energy going from the crankshaft to the belt, and again going from the belt to the alt shaft (but the belt coversion is VERY efficient), and more going from mechanical to electrical in the alt. And we all know there's resistance in all wires & connectors, so you lose more as the electricity flows from the alt to the battery, where even more is lost as it gets converted from electrical to chemical energy (inside the lead storage battery). And when the e-fan comes on, you lose more converting back from chemical to electrical; more flowing thru wires, connectors, & relay contacts; and finally a LOT more converting from electrical BACK to mechanical energy in the fan motor. And you never get allllllllllllllll those little losses back - they just blow away as heat that you burned gas to generate.

But if you just leave it as mechanical energy going thru the EFFICIENT (very little loss) belt to a mech fan, there's almost no waste.

And with a thermal clutch on that fan, it automatically DISconnects from the pulley when it's not needed, so there's NO extra load on the engine, JUST like when the e-fan relay is off. But the e-fan mfrs. don't tell you that - they only do their dyno tests with the e-fan locked in, and they probably use an oversized, inefficient fan to make the numbers as dramatic as possible so you'll fall for it and buy $450 worth of stuff you don't need, and which won't do what you want (save money).

The only reason to add an e-fan to a vehicle that doesn't have PCM control is so the driver can turn the fan off when he wants (like for driving thru deep water, which is why my '83 Bronco has an e-fan). But it STILL won't save any gas, or increase average power to the wheels, unless you leave it off when it needs to be on.

 

So I guess you saying the Alternator will cause as much parasitic power loss as the fans.. The alternator that is always spinning anyway that when called for energy simple gives it by way of the voltage regulator?
There are just to many guys on this board who have reported power gains and fuel economy gains for your argument to be taken very seriously.. E-fans will save a little gas they will give a little extra power.. There maybe an argument as to weather or not they are worth the hassle compared to the reliability of the mechanical fan and all but that's it.

 

Banshee...one little something to think about since you mentioned it...

One elextric fan, even in the stock shroud somehow, will not do the job of that mechanical fan. Electrical fans do not cool better than the stock set up and one will not do the job. It will take two in tough, hot situations. Just a tip.

 

So , with that reasoning, I guess if I dont use any electrical accessories, such as the radio or heater motor. I will get better gas milage. and a power increase. The thermal clutch mechanical fan still puts load on the engine when it is disengaged, the belt and pulley are still being spun by the motor. I agree that to recoup the costs of an efan set up and ones labor will take some time. That cash could just be spent on fuel. the fuel savings are probally minimal. comparable to putting on a torneau cover or keeping your windows up. but who wouldnt want a little more power.

 

No, the alt draws a few hundred times what a mech fan does. And it has to take roughly 4x from the engine what the e-fans put into the airstream due to all the losses. So to make it economical, you have to run the e-fan(s) 1/4 as much as a mech fan, and only a well-programmed PCM knows when it can get away with that.How do you figure the alternator is "always spinning anyway" but the fan isn't??? They BOTH take energy from the engine to spin. If you throw the belt while the engine is running, does the alternator just keep spinning & putting out power? NO. It comes to a SUDDEN stop. The fan, on the other hand, will keep spinning until you get below ~30mph. Why? Because the wind coming thru the radiator makes it spin. So how much power is it taking from the engine while the vehicle is moving at 60mph? NONE. But the alt ALWAYS needs power to spin, even if it's not putting out any electricity.You really have no comprehension of how an alternator works, do you? It doesn't put out anything thru the VR.Yeah, and think of all those guys who reported that the Earth was flat, AND the center of the universe. And all those guys with Tornados & fuel line magnets & hydrogen generators who report power & economy gains. Most people who "upgrade" their own vehicles have no real understanding of what they're actually doing, or how to interpret the results. So doing the same pointless mod as 100,000 other people doesn't validate the mod.

You get more performance & economy gain by dropping 20 lbs of steel from the bumpers than from switching to an e-fan with a dumb controller. Want proof? No one has made a passenger vehicle with a 5mph steel bumper for over 20 years. But until they went to PCM control, most axially-mounted engines still had mechanical fans. Right. Every bit of energy used by the vehicle, whether for propulsion, lights, sound, A/C, or anything else, comes out of the gasoline in the tank. ALL OF IT. So the less you waste (whether electrically or otherwise), the more you have for propulsion, or the less gas you have to burn for the same propulsion. That's why race cars don't have A/C, stereos, PW/PL/PM/PAnt/PS... The only energy you can get for free is the flow energy of the exhaust, which is why a turbo is used more often than a blower.

 

^^^^^^^^^ OK, now that's funny.

 

Lots of misconceptions in this thread. An alternator produces power on demand. By this I mean the more you ask of it the harder it works to give you what it needs. If you demand more current to power more items the field of the electromagnet around rotating mass gets stronger which means there is more load on the engine to produce the power. It is always turning with the rpms of the engine but how hard it works depends on what you ask of it. The voltage regulator just insures that the voltage never goes above a pre-determined voltage so that your electrical devices do not get fried. Most electric fans have a large current demand to start them but once spinning the load is not as bad. Remember there is no such thing as a free lunch. There is always a catch.

On your truck the clutch fan weighs about 15 pounds so getting that off the crankshaft can be a good thing. As Steve said you will not get your money back for a while but that is not a reason not to do it. Your engine spins up faster without the 15 pound fan mounted to it. Most E-fans are quieter than the clutch fan. The 1 or 2 MPG gain is of course beneficial in other ways besides your wallet. I think e-fans are worth it as do most manufacturers.

 

Guess you need to explan to the masses here why most new vehicles are being produced with electric fans including the Fords. Time to put this to rest, the majority of the members here with an elect fan are the winners. Oh, and by the way, the engine mounted fan on the 150s have an electrically controlled clutch

 

Yep.

Better cooling (if sized properly), ice-cold A/C, more room in the engine bay, quieter, etc ... good enough for me.


And - there is nothing Magical about factory PCM efan control - the Factory PCM e-fan control is still pretty 'dumb' - it still is just a basic On/Off controller based upon engine temps.

The only additional advantage is perhaps the ability to integrate into vehicle speed, A/C pressure, etc primaily for A/C control. But for basic engine cooling? Not sophisticated at all.

Like this LS1 controller, fer example: PCM driving relays - woohoo - no wizardry here ....

http://www.ls1fc.com/images/ls1coolingfansbu6.gif

Even the 2010 F150 is an on/off affair, even if it may have Canbus involvement ( SWAG here, lol )

Advanced controllers like DCControl FK-50P, Spal PWM-V3, etc offer soft-start to alleviate inrush, and will proportionally control the fan speeds based upon cooling demands. In most cases, using properly sized/rated fans the things rarely ramp up to full speed, except in gridlock or low-speed, high load conditions. But the mech fan will be running full-out here as well.

This last part is crucial - folks using mis-rated Fleabay crappola cheapo efans (you know, the ones marketed as being +2500cfm each but are only a fraction of that in real-world usage - they also come in nice ricey colours, lol) will incur a much higher fan duty cycle largely because the things are just not up to doing the same job as a bonfide large high-quality air-mover would.

A personal choice - not for the faint-of-heart as this is, after all yer engine cooling system you are affecting - if it's not 100% bullet-proof, don't go there. And - always carry spares and/or know how to quickly bypass for manual control.


MGD

 

i love my fans!!! didnt do it for the MPG gain. i really like having ICE COLD AC at idle. do that with a mech fan... and the engine spins up faster than with the mech fan..

 

It takes a 10 hp engine to run a 4200 watt 220 volt generator.
Running a 14 volt alternator at MAXIMUM DRAW only takes MAYBE 2 horsepower.
This is a silly argument beyond that.

 

The two do not correlate. Generators are different than alternators. It is a moot point anyway however as the benefits of the E-fan still outweigh the extra work placed on your alternator.

 

How much extra work? in HP? I think you would be hard pressed to find solid data to support a loss of more then .5 hp. I bet its less then that.

 

Doesn't matter really as it is still extra work. There is no free power in your vehicle. Doesn't matter if you add an iPod charger or a 5000 watt sound system, the electricity comes from more work performed by the alternator which is of course powered by your engine. The alternator acts like an electro-magnetic brake on your engine. The more power you demand the stronger the braking effect.

I would still install electric fans because I feel the benefits are worth the little bit of extra work.

 

OK then.