Manual Clutch Fan To Automatic Fan Concerns

[AustinDube]

Ive heard about swapping a manual fan to an electric and heard it can free up 10 horsepower and fuel economy due to less drag on the motor, but it will put more on the alternator too right?

 

[Honky Kong jr]

I don't believe enough to warrant not going electric fans

 

[yevgenievich]

It would be recomended to upgrade the alternator before going with electric fan. But it depends on the electric system of the vehicle. On my suburban, when everything is on, there is not enough alternator to run electric fan.

 

[TIE_Fightertk06]

You have a clutch fan on that truck, not a fixed fan, right? If some PO put a fixed fan on there, that's a power drain, for sure. Clutch fans, though, aren't so bad...

There have been dyno comparisons, and a gain of 10 HP or more may be a realistic, and even more if you do have a fixed fan.

But, how are you driving the truck?

If you're balls out WOT all the time, then yeah, the difference may be enough to justify the expenditures and time for a good set of fans and everything that goes with the swap if you're frugal about it. See, the parasitic drag of a clutched fan is negligible at lower RPM... 3 or 4 horse on the dyno. It's not until you're up over 4K that you'll see the real difference in how the fan drags, but how often are you running that far up in the rev range?

Money may be better spent on something that'll give you better gains, depending on where you are with your truck and how the cooling system is performing now.

Just something to think about, that's all.

 

[yevgenievich]

Engine masters did a test on a warmed over motor and it showed negligable losses at lower rpms and up to 20hp loss at higher rpms. That convinced me to stay with clutch style fan for now. 98% of the time the engine in the suburban never sees more than 2.5k rpm

 

[4WDKC]

The drain of the extra load on the alternator is only when the fan is on, usually while sitting still. The ideal way to have the fan work is so it shuts off above 30 mph as there is usually enough airflow to cool the radiator while moving. This increases mileage as there is no drag while moving, none from a clutch fan and no additional on the alternator. I have my vette set up to turn the fan on at 200 and off at 190, this allows the fan to shut off on the interstate.

 

[AustinDube]

Yeah they both sound like good options i'll stick with mine for now and yes it is a fixed fan on there no clutch, and the radiator has a bunch of wacky things done to it and I'll want to replace it and an electric fan would probably clean up my engine bay a little bit

 

[Jrgunn5150]

I use electric fans exclusively, and the newest alternator possible.

I have a CS144 and Mercury Villager fan to put on my C10 ASAP.