fan query

[yucatec]

Dear Panthers,
Sorry if my query has been answered in other threads. My search didn't find any,

My interest is in performance and economy. As someone wrote - Gadget I think - I can get both only by increasing engine efficiency. One way to do that is with an electric fan. Can anyone tell me what performance/economy I could expect?

Donald McCaig

[mrltd]

Maybe 1-2mpg. Other benefits are quicker warming up in cold weather and much easier belt changes. I didn't notice much for performance though.

[Blaze86Vic]

You would have at those 6000rpms.

Performance isn't really noticeable, since it makes no difference in low RPMs. It might make 2-5hp difference at 5500rpm, if that. But the MPG will go up.

[gadget73]

One thing I'm noticing with my fan is that it needs a better controller. Right now I've got the on/off temperature probe type, and at idle, even with the upgraded alternator, it discharges the battery with the AC running. Too much stuff running, and that 30 amps or so the fan pulls really takes a toll. Its bad enough that at night, my stereo will kick in and out from low voltage when I'm sitting at a stop for too long. I have plans on getting something like a DCC controller that will vary the fan speed based on demand instead of just on or off.

Oh, I did get about 1-2 mpg fuel economy improvement with it, and my AC works absolutely fantastic in traffic. I used to have pretty pathetic AC performance at idle from less air movement. The e-fan does a nice job of keeping air moving across the condenser.

[Archangel]

Thain, what pulley are you running on that alternator? When I was installing my 3G alternator I swapped the pulley out with the one from the stocker, it's smaller so you'll be getting more power out of the alternator at lower rpms.

[Blaze86Vic]

What the hell is wrong with your car Thain? I used the largest alternator pulley I could find, have an electric fan, push a stereo amp, and with high beams on and A/C kickin' I never had my stereo drop out at a light. And I don't have the 3G upgrade either.

[gadget73]

standard 3g alternator, stock pulley that comes with it. its marginally bigger, but not enough to matter. the problem is the mark viii fan just eats so much power that almost nothing is going to keep up. that, and the blower for the hvac sucks probably another 20 amps or so, so at idle i'm pulling a good 40-50 amps between just fan motors. add to that an ac compressor, headlights, stereo, and whatever the engine electronics need, and that makes for a hell of a current draw. shutting the hvac blower down to minimum is enough to bring the power back up, but if i do that for long my evaporator freezes. i also tend to leave the fan on auto, and its almost never running at its lowest setting. all that, and quite frankly the stereo does sort of suck. i've never pulled a voltage reading to see what i'm actually down to, but the instrument panel is definitely dimmer at idle with all the stuff on. bringing the engine to 1000 rpm fixes it, but when you have a ~700 rpm base idle in gear that doesn't help much. battery is the stock rated 625 cca. probably installing a larger one wouldn't hurt me any but this one is a year old and right now i'm not planning on replacing it. i should have it load tested though, i have a sneaky suspicion its got a bad cell. it should be under warranty for a free replacement still.

[Glen]

Where are you guys finding all these holes to set up a water temp gauge, fan temp switch, ECM sensor, ect? There are only 2 in the intake as far as I know?

[85crownHPP]

thaine - have you done a current draw test to see how many amps its actually able to put out?

[gadget73]

Where are you guys finding all these holes to set up a water temp gauge, fan temp switch, ECM sensor, ect? There are only 2 in the intake as far as I know?

my fan sensor is a dry sensor. its actually zip tied to the upper radiator hose. my water temp gauge goes in the lower manifold where the factory gauge is. my thermostat neck is from a truck, and has a sensor bung in it, so my factory gauge sender is installed there. if you need additional sensor spots, mark vii have this neat little pipe thing with a sensor in the heater hose. one of those could be installed very easily and used for an additional sensor location.


pete: no. its never been load tested. maybe i should do that.

[yucatec]

Dear Panthers,
So Okay. An electric fan might improve gas mileage 1/2 mpg but it also might not be reliable and might draw down my mustang alternator to dangerous levels. Is that the news?
Donald McCaig

[gadget73]

They aren't really unreliable. Most cars fitted with e-fans from the factory have no problems with them for many many miles. The trick is in the controller. A simple on/off control will put heavy demands on the alternator when the fan kicks on. A Mark VIII or Taurus fan can draw about 80 amps on startup, and level out around 35 amps. If you have something like a DCC controller, it will vary the fan speed to maintain a stable temperature, and start the fan up slowly so there is no huge surge of current.

[Lincolnmania]

it's the draw at startup that's the problem......solution, a special fan controller that starts the fan slowly to reduce starting amperage draw........gadget also may have a battery on it's way out........highway mileage should increase 1 mpg at least

[Blaze86Vic]

go electric fan, the benefits far outweigh the negatives.

[Glen]

I have looked at the Taurus and the Mark. There are a lot of wires coming off the fan and the hook ups. I'm an old guy and don't know a lot about the newer cars (92 and up). What wires and sensors do I need to get? The U pull & pay be me has a ton of the Taurus and Marks in it. I have found single and duel fans, which is the best to get?