What do you guys recommend? I am thinking about installing electric fans. Is the cooling better with the electric fans or the stock clutch fan? I noticed the 05 trucks come with electric fans, can these work on the 01 8.1 / Alli? How would I setup the wiring to be automatic, and have AC function work?

Haven't got them installed yet but have purchased the Flex-A-Lite #280 dual 15 inch fans. You can read about them at this site http://www.flex-a-lite.com/auto/html/monster-electric.html:grd: .

I did some research on this a while back and this is what I came up with.

1) Electric fans do not pull as much air through as the stock clutch fan at higher RPM's. Even with dual fans.
2) They do however pull more air when the RPMS are low, like in bumper to bumper traffic.
3) The electric fans turn on automatically when the A/C is on and this helps the a/c work better when there is not a lot of air flow through the radiator/condensor. Again at slow speeds or in traffic.
4) Electric fan give you a little more horse power but when dual electric fans are on full blast they draw a lot of amps off the alternator and this creates more load on the engine which takes HP away so it is tricky to see the real benefits

I used to do a lot of towing and after talking with a lot of people I trust I stayed with the stock clutch fan. Just my $.02

Chris

That does make alot of sense. But What I keep thinking is, I do not need more flow at higher RPM. At that point there is alot of frontal air flow. I am worried about sitting in traffic with the AC in the desert.

My electric fans work great. At highway speeds (with the fans' thermostat set correctly), my fans turn off, and it runs 15° cooler! Found out the fanbelt, trying to turn the fan/water pump, was slipping at high RPMs, slowing the rate the coolant was being pumped through the engine. (At 65 MPH, the motor was turning 4300 RPM.) This is on my gasser though... I personally would need to see the CFM (Cubic Feet per Minute) the Duramax needs accross it's radiator(s) before I would think of sticking one on my truck. I would worry about the extra heat from the intercooler and the fans' ability to move enough CFMs of air to keep it all cool! Flexalite has CFM numbers for their various models, just need some numbers that Chevy/GMC gets (CFM wise) when the clutch fan is at maximum engagement. Any Tech can chime in if you know the answer I/WE seek now... Thanks.

I had e-fans on my old Z71. Worked great when not towing and made the AC ice cold and slow speeds. But as soon as I towed, even a light load, up any hill it would get real hot.