Anyone removed clutch fan and replaced with electric?

[X5 Manic]

In for an interesting idea. Any way to free up power on the 3.0 is always good.

[bcredliner]

Info about electric fans

Mechanical vs. Electric Fans: Which is Best for Your Vehicle? - OnAllCylinders

https://www.youtube.com/watch?v=z8_JT0ezqGw

Electric Fan 4-1-1: Everything You Need to Know About Electric Fans - OnAllCylinders

The horsepower gained is not mentioned because it varies by application. I spoke with Flex-a-lite tech center prior to my install. The estimate for my application was 4-10hp. with the fan running and without consideration if the stock pusher fan was running or not.

On a dragstrip---After the race I set the fan to run all the time to cool the engine down to the starting temp of the first race. On the street-- I set the fan to come on just before the aux fan. At an idle it runs less than 30 seconds when it is 90+ degrees F. That means on the strip or street neither the pusher or puller fan are running most of the time as long as the air conditioning is off.

[bcredliner]

For those following this thread. I will no longer respond to Trader 4 in this thread.

Trader 4, I concede.

[DSSA]

An interesting read on parasitic loss from mechanical fans:

Dyno testing on fans, alternators and oil.....all here!

A couple of issues to note if reading it:

1) The fan/clutch systems on the older Chevy Smallblock is going to be quite a bit larger/heavier than on the X5s.

2) Fan draw on a stationary dyno will differ than while driving (be larger) due to frontal flow in proportion to the speed you're traveling.

However, it gives a little insight on the subject with measured data.

I personally wouldn't remove my mechanical fan simply for the sake of performance gains on something like the X5, however, the other aspects like being able to have control over what temperature it starts/stops, being less of a PITA to work on the car, etc. is why I would switch it over like my E39 and Wrangler should the motivation/opportunity arise.

I wouldn't suggest it be a "go to" modification, but like all modifications to a car, whether it is worth it or not depends on your own desires/needs.

[EH6TunerDaniel]

I didn't do the mod to gain any power, but rather save from future failures. I have seen, on the same e46, a fan clutch go bad and destroy the hood, rad, water pump, hoses, expansion tank, fan, and thermostat,plus leave the vehicle inop. Later on the same vehicle had the water pump seize, which threw the fan off and did the same damage all over again except for the hood and again leave the vehicle inop.

These failures alone are enough for me to want to prevent this damage. If the fan fails it's not going to break anything else. And the water pump has no additional strain on the bearing so it is also less likely to fail. Plus if the fan fails I can limp it home.

Did I gain and power and fuel economy? Maybe, but probably nothing noticeable. However, I gained peace of mind, reliability, and control over what temp the fan will turn on at while retaining the ability to run after the vehicle is turned off.

[srmmmm]

I recall lab work I did at General Motors Institute during Buick's turbo V-6 development measuring engine efficiencies. With the heavy duty cooling option on an air-conditioned Regal, if the fan clutch engaged during normal highway cruising, (think long uphill climb in Nevada), that 7 bladed fan pulled 14 horsepower at 2500 RPM. If the clutch on the X5 mechanical fan is a thermostatically controlled "lock-up" style, the 4-10 horsepower consumption rating at upper rpms is quite believable.

At Marmon Motors in the late eighties, our engineering team toyed with electric pusher fans on Class VIII trucks until they calculated that it would take four fans with 9 horsepower motors to equal the airflow capability of the engine driven mechanical fan.

The one major change that has allowed automobiles to go to electric cooling fans has been the adoption of aluminum core radiators and their better heat transfer capabilities over copper/brass radiators.

2002 X5 3.0 281,150 miles
2004 325i 120,600 miles

[bcredliner]

Replacing the clutch fan was one of the last mods I made. Previous to that I added a Dinan airbox, exhaust, MAF, throttle body, engine software and transmission software. Then I added meth injection, 150 shot of nitrous. That was the information I gave to the tech at Flex-a-fan with the resulting estimate of a gain of 7-10 HP. Lets assume the gain in horsepower is 10. Depending on the starting HP the time will increase from about .08-1.2 tenths. The improvement decreases the greater the HP. Even at .08 the cost/benefit time improvement is great.

[crystalworks]

Originally Posted by trader4

Anybody that believes that 4 to 10hp gain claim should consider
what hp is required to drive similar size fans, moving similar
amounts of air and apply some logic. And they should also
consider that if that mechanical fan was really using 10hp,
it would be about 20% of the hp it takes driving on the highway.
That would give you a HUGE, easy boost in MPG and BMW,
desperate to improve MPG would have been pretty dumb not to
know that.

Here's a 10hp fan:
http://www.grainger.com/product/DAYTON-Med-Duty-Fan-7M872

It has a 5ft blade and moves 66,000 CFM. Nuff said.

And note that I'm not saying it doesn't have some small increase
in fuel efficiency, etc, I'm just saying I don't buy that it's 4 or
10HP or worth all the fuss. As always, your car, your money,
your choice.

Dyno proven 7hp on my 91 318is M42 car after deleting the parasitic fan... it can make a big difference.

[PropellerHead]

Originally Posted by crystalworks

Dyno proven 7hp on my 91 318is M42 car after deleting the parasitic fan... it can make a big difference.

That's impossible.

Signed,

Trader4

[crystalworks]

Originally Posted by PropellerHead

That's impossible.

Signed,

Trader4

Don't know what to tell you... the runs were on the same dyno. The days were different but the temp was within 10 degrees I believe. Only difference in runs on the car was the deleting of the parasitic fan... so?

I can also say I could immediately feel the difference without the fan on there. Would I say that EVERYONE will experience these kinds of gains... no. But the gains CAN be nice.