Pully vs. Electric fan

I'm not sold on the extra power, before you all attack let me explain. with an eletric fan you have moved the drag from the fan it self to the altenator. When the fan kicks on on my new car the RPM drops from the drag on the alt. Now how much of a drag difference is there I don't know surely I would think it is less than the straight fan.

And if you are worried about daily driving you can always connect a small LED light that comes on when the fan is running. That is what I did to my mustang.

 

Thack,
wouldn't that light just tell you there is power going to the fan and not that it is operating?
i tried to get a light wired to my fan 2 yrs. ago but no one could tell me how to wire it to know if the fan ...was not turning ...(under power)...
when the relay puts power to the fan the light comes on...that doesn't mean the fan is running
maybe you are the one...

...Frank :Handshake

 

That is very true, but aside from when you are just crusing around town or stuck in traffic, how much is the fan actually on? This time of the year, I leave my fan off 90% of the time. When that fan is off, there is no drag from it on the alternator. Going down the interstate is another good example. The mechanical fan is still putting constant drag on the motor even when it's not needed going down the interstate. I can just flip the electric one off, the drag on the alternator is eliminated. You can hear the difference for sure between when it's on and off, and I can feel the difference in acceleration in my car.

My fan is on a toggle switch that lights up blue when the fan is on. I don't know if there is a way you could have that light tell you that the fan is actually running or not.

When I was just testing if the electric fan was going to work alright, I didn't have it on a relay yet, just wired straight to the switch (only drove it like 10 miles like that). The bulb in the switch was lighting up when I was going down the interstate with the fan OFF due to the fact that the wind was turning the fan fast enough for it to generate power. On a 2 speed fan, I wonder if the coil that is not in use generates power when the fan is running. For example, if you have the fan on high, is the lower speed coil generating any power? If it was, it seems you could use that to power a bulb and if the fan is running that light would be lit up. I have no idea though, just thinking out loud.

 

on my 76 maverick v8, I have a 160 degree t-stat,a new 3 row max-cooling radiator, 7 blade termo-clucth mechanical fan and the hottest I could the the engine was 163 degrees in traffic at 98 degrees ambient tempeture !!!!!! thats after installing a factory original fan shroud I got from e-bay !!!!! without the shroud ,the temp was 195 to 215 !!!! When I install the universal AC system back in, I'll use a electric fan on the condenser just incase...

 

Jamie, is this installed on an I6? Was this an off the shelf item at Auto Zone and do you remember a part# and price? I may be interested in doing something similar. Thanks.

 

Yes, it's true that you cannot mount an mechanical fan on a FWD, but that's not the real reason behind the electric fan. Many RWD cars also have electric fans from the factory. Electric fans are more efficient. By reduce the drag created by a traditional fan (especially those without a clutch), manufacturers could help their goal of better gas mileage. Remember that there are gov't requirements - and these requirements are about to get tighter by the way. Any reduction in drag is an increase in efficiency. Now, I know you have to run an alternator to support it, but like Jamie said - the fan doesn't run all the time.
Another big benefit that Frank mentioned earlier in the thread is that the fan is blowing hard in stop and go traffic. An all-stock car may stay cool at idle, but that condenser is still getting hot if the A/C is on - this is why some factory electric fans come on with the A/C regardless of the temp and also why aftermarket fan controllers have a secondary power input (from the compressor power source).
For those of us with non-stock cars, the electric fan is a life saver. There is no way my '73 is going to stay cool in traffic for an extended period of time with a mechanical fan, even without A/C.
I only have an electric fan on my '73 Maverick and I love it. In fact, I had considered dropping them into my other cars. You can buy an adjustable controller from the parts store for about $30.

 

It may be affecting the new car becuase of the aluminum flywheel, less inertia. And I will also add that the mustang and the new maverick have eletric fans, Tammy's doesn't becuase her cars cooling system works great as is.

 

Did Radmav's dog avatar attack the cat in yours? Cause it sure looks like they both have the same disease.

 

Let's think about this now, it does not matter how much current you draw there would be no increased drag on the engine caused by turning an Alternator.

 

Yes there is... The more power you're using, the harder the alternator has to work. The harder the alternator is working, the the more drag it puts on the engine (parasitic loss). On my brother's little Nissan Sentra, that little 4 banger looses like 150 RPM's when the fans kick on at idle.

Reminds me of when I was little and had the headlight and tail light powered by a generator on the rear wheel of my bicycle (a '71 Schwinn Grey Ghost my dad and I restored). My friends and I would always play around with hooking stuff up to that generator, like old car headlights and stuff, and you could always tell the difference in how hard it was to ride that bike depending on how much power whatever you had hooked up was trying to pull from that generator.

 

Jamie is correct!!!

 

Yes, it's on an I6. I don't remember the part number or price I paid for it. It was an off the shelf item, I just went in and told then I was looking for a universal electric fan, they took me behind the counter and showed me the three different sizes they have. I'd have to go out and measure it, but I'm 90% sure mine is a 14 inch fan. I want to say it was a "Torque Flow" brand or something like that. I had to mount it off center slightly on the radiator in order for it to clear the water pump, however I have a three core '70 Mustang radiator, so the extra thickness may have something to do with that. I would suggest a slightly bigger fan then the one I have, if you can squeeze it in there. On extremely hot days, the temp will just barely start creeping up if I get stuck in traffic for more then about 20 minutes. I never had it get higher then 195 though.

 

This drag race site claims you can gain 35hp turning off the alternator http://www.dragtrucks.com/tips/tips.htm

 

Electric fan for sure. Never had a problem with one Had one of those cool flex fan well it was cool until it came apart and went through the hood That was about 2 weeks after i painted my 1965 mustang I WAS MAD!!!! 10'000 rpm my a$$ it came apart at about 5600. Just a warning to anybody using one!!!!!!!

 

35hp is a bit high.... 5KW (5000 watts) only takes 10hp and I doubt your alternator is putting out 350 amps. 350 amps x 14.3 volts = 5KW
If you need to know how much hp your alternator is using multiply the amp capacity (60) times the volts (14.3) and multiply by 0.0007457... 60 x 14.3 = 858 858 x .0007457 = .6398hp If you add in losses for the belts and the inertial mass you get just under .82hp
You can gain about .01 seconds in the quarter mile by shutting off the alternator. (if you are actually using 60 amps while making your run.)