Electric Flex-a-lite Fan Questions

clm7214 · July 21, 2006

OK, i want to install one of those 5,500 cfm electric get-ups. All ive found is debates on whether or not it improves MPG and fan clutch arguments. We all know belt driven fans rob horsepower. Im looking for guys who have installed electric fans and what their opinions are on how its workin for them. I drive from 29 Palms CA to Buckeye AZ all the time, pretty much the hottest place around. Im hopin it will help keep the AC nice and cold, free up some mpg, and keep it cooler 4 wheelin and towin the camper around the desert.

Its a 2004 2500HD with the 6.0L

Not looking for theories or opinions, but real world experience. Thanks

454ss · July 21, 2006

i was going to get the same set up for my truck but i was told right from flex-a-lite tech service that they do not reccomend them towing, you will run hotter than with your stock clutch fan. so i decided not to get them.

clm7214 · July 21, 2006

I read that on their website. Its not a heavy trailer. Its a pop-up with 2 queen size beds and a kitchen, so I think it should be fine, if not better. Anyone have one installed?

Brian1 · July 27, 2006

Installed one on my 2003 2500 Avalanche with the 8100 vortec earlier this year. Haven't really seen any improvement on mileage to speak of. Also there does seem to have a bit more power. Did it in about 2 hours. Most time was to mount the fan and locating the wire to sense when AC compressor was engage. Real pain if needing to connect back down on the compressor. Luckily I had my books on the Avalanche from Helms and found the wire in the engine compartment fuse panel. Best $300 dollars I ever spent. Has come in handing do many things like adding a remote start. The install docs for it missed one wire needed on one of the ignition circuits.

Brian1

dizzy · July 29, 2006

Fan is only good for 0-25MPH, once you get over that speed more air is coming in than the fan can pull anyway.

clm7214 · July 29, 2006

Thats true, thats why having an electric fan frees up rotating weight, because its not dragging on the engine when its on the highway. But if youve been in the stop and go traffic in Phoenix Arizona, youd know why im asking about this electric fan.

asilverblazer · July 29, 2006

Fan is only good for 0-25MPH, once you get over that speed more air is coming in than the fan can pull anyway.

<{POST_SNAPBACK}>

Make sense but how much CFM is coming through at say 70mph, 45mph, etc... Also, is that how much air is hitting the radiator or going through the fan shroud?

If I had the time/desire to figure how much CFM at 70mph I would...

70mph=176400fph (feet per hour)=2940fpm

soooo surface area of radiator x 2940 = cfm?

masterp2 · July 29, 2006

Thats true, thats why having an electric fan frees up rotating weight, because its not dragging on the engine when its on the highway. But if youve been in the stop and go traffic in Phoenix Arizona, youd know why im asking about this electric fan.

<{POST_SNAPBACK}>

I know exactly what you are talking about. You should make some time to come by. I have developed an airflow solution that will make your fan go byby.

The elec fan will probably do what you are looking for, but don't be fooled by the cfm ratings. They are always rated with zero resistance, IOW when not shrouded behind a radiator. You will be lucky to get half the 5500 while at low speed. That will lead to overheating out here, under load.

The thermo-viscous fan, when in full slip, is extremely mild parasitic load. When she get's hooked up, it is because natural airflow is lacking, this platform is somewhat notorious for poor cooling aerodynamics. The trick is, to instill the airflow you need from the vehicles natural kinetic energy. The best part about that is you don't have to expand your electrical system, or replace the alternator every six months (20-30 amps for those fans IIRC). The other best part is that it expands your cooling systems total heat rejection.

If I have peaked your interest, just let me know.

[email protected]

masterp2 · July 29, 2006

70mph=176400fph (feet per hour)=2940fpm

soooo surface area of radiator x 2940 = cfm?

<{POST_SNAPBACK}>

That is a nice try, wish that were the case. If, hypothetically the fan were completely off (no rotation), you would measure airflow getting past the rad at about 10-11 mph, assuming a 70 mph free stream

clm7214 · July 30, 2006

Thats true, thats why having an electric fan frees up rotating weight, because its not dragging on the engine when its on the highway. But if youve been in the stop and go traffic in Phoenix Arizona, youd know why im asking about this electric fan.

<{POST_SNAPBACK}>

I know exactly what you are talking about. You should make some time to come by. I have developed an airflow solution that will make your fan go byby.

The elec fan will probably do what you are looking for, but don't be fooled by the cfm ratings. They are always rated with zero resistance, IOW when not shrouded behind a radiator. You will be lucky to get half the 5500 while at low speed. That will lead to overheating out here, under load.

The thermo-viscous fan, when in full slip, is extremely mild parasitic load. When she get's hooked up, it is because natural airflow is lacking, this platform is somewhat notorious for poor cooling aerodynamics. The trick is, to instill the airflow you need from the vehicles natural kinetic energy. The best part about that is you don't have to expand your electrical system, or replace the alternator every six months (20-30 amps for those fans IIRC). The other best part is that it expands your cooling systems total heat rejection.

If I have peaked your interest, just let me know.

[email protected]

<{POST_SNAPBACK}>

AHH, finally. Another Arizonan. I live out in Buckeye. I was gettin really tired of guys from like Michigan telling me what setup i should use. I mean, yesterday it was 123 in the shade on the back porch. Anyways, whats this setup you speak of ?