Originally Posted by JCS30TH
So why didn't ford put them on our trucks? With the miles I drive the payback on mpg would be just over 6 months.
For what it's worth.. I was a cooling engineer for 6 years (all ford projects)
Ford has a policy about thier trucks concerning towing and hot weather extended idling. (this applies to police cars too) In those conditions you generally have low rpms and high loads. That means high heat and not much pump speed to keep the coolant velocity up.
The solution is to in effect *overcool* the fluid at low rpms / vehicle speeds. Hence the mechanical fan that spins all the time.
Going with a e-fan is certianly doable in those conditions. But to meet the high standards set (by Ford) you'd have to upgrade the electrical system to handle the substancial loads at such rpms. A good part of which is at idle or nearly at idle in hot climates.
If you guys are'nt towing 3000+lbs then do this mod. It's well worth your effort and expense. The water pumps bearing will live for ever, the motor will run smoother, you'll get better milage, the motor will warm up quicker, and as long as you get a high quality aftermarket setup you won't need to sweat on road conditions like salt and grime. (I personally use flex-a-lite products)
As far as power increases.. yes you will see some. But not much really. The modern day mechanical fans are very very efficient once they are up to operating temps.
Going down the hwy you'll only be saving about 1/4 hp. Full rpm acceleration you'll see around 8-10hp at best (depending on the fans fluid temp). And the biggest power gains come at very low rpms. Like just off idle. You gotta remember that your butt will only tell a difference in power based on percentage. For example you can't really feel a 5ft lbs TQ increase at 4000rpms on a 240TQ motor. But a 5ft lbs TQ increase at 1500 rpms is definately noticable.
Just off idle the motor is making something like 40ft lbs of TQ. Removing the mech fan can free up a noticable amount at those low power levels and you'll feel it.
This will be one of the first mods to my new truck. (I have a S-blade and flex-a-lite controller ready for it)