Loss of Power after New Fan Clutch

Devo the dog wrote:

ScottG wrote:
Devo, that is a complicated question. Under the conditions you state, it probably takes no power at all - fan can be disconnected. But When conditions are at their worst, like climbing mountain w/AC and heavy trailer, it takes a lot of power My truck uses up to 23 HP just to turn the fan.

If it's a complicated question, yet you have a solution, then it's not a complicated question.

You said it yourself: it doesn't take any HP.

If the OP is experiencing this problem a lot and "everything" was replaced, then there is a problem that still exists. I also think it's funny that coolant and oil temps aren't even mentioned.

But, we know that the fan roars and the truck is 10 mph slower. LOL. Something is wrong.

BTW, how are you measuring that it takes 23 hp to turn your fan? Dyno?

I see the usual downward slope of this thread so this is my last post on the subject.

First, I said it doesn't take any power just going down the highway under light load.
Second, I don't know that I presented a solution - I simply made a suggestion. In no way am I or anyone else here qualified to redesign the OP's cooling system.
I have worked through cooling problems on vintage V8 cars though and have learned a few things. There are far more variables to it than most think.

I think the OP should use it as-is and see if his results are consistent. Indeed, it is hard to believe he lost that much speed but I won't discount his experience. OTOH, a fan roaring while it's working hard is a good thing. If it's roaring anytime he's under 10 MPH, even when the eng is at normal op temp and the AC is off means that clutch is junk.
My new OEM clutch does roar anytime I'm going that slow with the AC on - that's a positive change. Not only will the AC work better but the pressures will be lower as well, making life easier for the compressor.

The 23 HP figure is what Dodge engineering reported. This is not the power it uses just going down the road under light load. It is the amount of power it *can* use when called on.

Have a good day.