HP loss to fan (1 Viewer)

[blbuck12]

Have been planning on moving over to an electric fan to clean up the engine bay and leave all hp for the wheels. Engine Masters (Motor Trend guys) tested a Chevy 350 with a bunch of different fans to see how much hp they use. Definitely going to be switching now, the 2f needs all the help it can get. Worth a watch, plastic flex fans and factory fixed blade fans killed the most power.

Cooling Fan Shoot-Out!

Has anyone's butt dyno noticed a increase in hp when switching to electric fans?

 

[LAMBCRUSHER]

ALL i KNOW IS WHEN i SWITCHED TO ELECTRIC, MY TEMP WENT UP...AND UP...AND UP...whatever the OEM fan draws from the wheels is worth every pony...

 

[RockDoc]

Conventional wisdom around here is stay with engine driven clutch fan unless an engine swap makes that a problematic option. Just like an air filter's job is to filter the air, not let more air (and dust like a K & N) through, the fan is for cooling the engine, not freeing a touch of mechanical power and overtaxing the charging system.

Having driven with the fan fixed solid when the clutch is in poor shape, I can tell you the clutch does a good job of limiting parasitic losses.

 

[SteveH]

We almost need a sticky for this .

Stick with the energy-sapping belt-driven fan. Besides, the OEM alternator has its work cut out for it with such taxing add-ons as the heater fan and headlights.

 

[Shacklewhacker]

As repeated here - stick with factory fan and clutch. OEM if you can afford it.
As has been stated before, you have to remember, these things were engineered and built for service all over the world - the cooling systems on these beasts were engineered for climates ranging from 40 below zero, to 125 degrees. It's why they are still all over the middle east (and yes - not only diesel versions - gassers like US market).
Trust the Toyota engineers. Anyhow, HP really isn't the target in the 2F - Torque is.

 

[blbuck12]

So the concern with the electric fan is electrical load and the alternator not keeping up. Upgrading to a GM alternator with more amps would solve that easily enough.

If you're losing HP, you're losing Torque. HP is a function of Torque.

 

[cruisermatt]

So the concern with the electric fan is electrical load and the alternator not keeping up. Upgrading to a GM alternator with more amps would solve that easily enough.

If you're losing HP, you're losing Torque. HP is a function of Torque.

As you can see, most on this forum think that the mechanical fan is perfect and to switch to electric would be sacrilege.

Electric fans are fine. Just set it up properly.

That being said, I doubt you will be able to tell a difference in power.

 

[60 toy ota]

I saw that video earlier today and had the same thoughts. In the end I reasoned that the draw increases with RPM, and with the majority of our miles being driven arguably under 3-3.5k, it's not gonna me as big a deal as with the SBC. That and the fact that my friend almost lost his head gasket recently due to his fan motor dying makes me want to leave well-enough alone.

 

[LAMBCRUSHER]

So the concern with the electric fan is electrical load and the alternator not keeping up. Upgrading to a GM alternator with more amps would solve that easily enough.

If you're losing HP, you're losing Torque. HP is a function of Torque.

NO, the concern of an electric fan is is don't do jack sheeit. didn't you read the posts^^^?

 

[blbuck12]

I saw that was your concern, as you had difficulty keeping your motor cool. However, RockDoc and SteveH both mentioned the load placed on the electrical system and nothing about not being able to provide ample cooling. Didn't YOU read the posts^^^?!

@60 toy ota That's what I was thinking, it's based on RPM. So draw doesn't change with engine size/power. So a fan would draw that same amount of power from any engine with a given rpm. So at 3.6k rpm a fan might draw 10hp, doesn't matter if the motor is 135hp or 500hp, a 2f or a chevy v8... Just thought it was interesting given that the 2f is stock 135hp @3,600rpm, and I'm always looking for ways get more oomph.

I also found the below article that discusses power loss due to automatic transmissions and fans, and they measured a 13hp (6%) loss with a fan at 3,600rpm

Drivetrain Power Loss

 

[LAMBCRUSHER]

they both added that facet, but what do I know? good luck with it

 

[Shacklewhacker]

I guess at the end of the day, it's not sacrilege, nor problematic, and I don't know who's turning 3600 out of a 2F (good lawdy), you choose - right? Upgrade an alternator, keep the factory fan - totally the burden of the freedom of choice - right? We love these things.
I look at these things from a simple layman's view - Toyota engineers had tons of electric fans available to them when re-engineering the 60 series in the late 70's issuing in the 80's. They are automotive engineers with massive budgets, and a sh*t load of time and experience making FJs behind them. Sure, they operate under a "budget," but I trust their design results more than my own, or pretty much anyone else out there (unless you were/are one of them and can say "that could have been better with X").
To me, at the end of the day, that's why we are all here on this forum - they got the sh*t right. We grumble about 30+ year old machines that most of us would trust as much a a new car.
Gotta love the FJ.

 

[60 toy ota]

That's what I was thinking, it's based on RPM. So draw doesn't change with engine size/power. So a fan would draw that same amount of power from any engine with a given rpm. So at 3.6k rpm a fan might draw 10hp, doesn't matter if the motor is 135hp or 500hp, a 2f or a chevy v8...

No you're totally right, I only compared the two because of the different revving capabilites

 

[tclark]

While I totally understand the desire to stay mechanical(such as myself), it simply makes no sense that an electric fan can't work just fine. There are far too many vehicles on the road with much higher outputs and higher loads that do just fine with them.

I think the probably is usually they're just not well thought out or implemented when swapped, or at least the ones I've seen. You certainly can't just go buy any ole fan and slap it on there, it needs to designed and installed properly.

Is it worth it on a 2F? That's debatable, but it's certainly possible.

 

[Shacklewhacker]

Here's some info about CFMs, and a pretty clean setup if your going down the path...
Fj60 diesel conversion

 

[Elbert]

no real value added by changing to electric fan. If you off-road I would expressly not change, the fan clutch fan with matching fan clutch and related shroud.....bullet-proof.

 

[psulick3]

@60 toy ota was right. Check the torque curves on the episode. Most of the loss happens above 4500 RPM. I don't think I've ever hit 4K with my 2F. The losses should be minimized so why fiddle with what works? If you really want to get inspired and in trouble watch the Engine Masters Ep about cams. You'll be swapping in no time and more than offset what you lose from your fan.