clutch fan replaced with electric?

[mikes94q]

Has anyone here ditched the clutch fan for an electric fan? I'm in need of replacing mine and the prices are a bit steep, and if I can go electric should gain some power from less drag.

[Infinitiguy19]

Hate to be "that guy" but many people have asked this and everything they get the same answer. With a electric fan the alternator has to work harder which negates any possible benefit...

[bullittandy]

Swapping an electric fan for mechanical is usually worth 10-25 HP and 1-2 mpg.

It is a very worthwhile trade but electric fans are a little less reliable (at least temp sensors are and fuses that go with the fan) and it requires a little extra engineering.

i don't know anyone on the board thats done it-I've always wanted to but. . .

[qship96]

Swapping an electric fan for mechanical is usually worth 10-25 HP and 1-2 mpg.

It is a very worthwhile trade but electric fans are a little less reliable (at least temp sensors are and fuses that go with the fan) and it requires a little extra engineering.

i don't know anyone on the board thats done it-I've always wanted to but. . .

If you could get anywhere NEAR those figures, every manufacturer would have engineered electric fans into every engine, as the mpg savings would save them tens of millions in government fees......obviously the savings are nil when you consider the extra draw from alternator created by the additional load the electric fans draw. And 10-25 horsepower???? The a/c compressor does not even use anywhere near that.....a clutch driven fan certainly uses less than the compressor,especially once at speed and it is freewheeling.

[subtle_driver]

Hate to be "that guy" but many people have asked this and everything they get the same answer. With a electric fan the alternator has to work harder which negates any possible benefit...

You are partially wrong. Air moves through the radiator when you are moving. When the fan is off, the benefits are free revving, better gas mileage and more power.

the only time the fan will kick on, is if you are idling in traffic, or have the a/c on.Do you really need more power when you are sitting in traffic?

[subtle_driver]

If you could get anywhere NEAR those figures, every manufacturer would have engineered electric fans into every engine, as the mpg savings would save them tens of millions in government fees......

almost every car that comes in my shop has an electric fan from the factory. Benz, BMW, Infiniti, Audi, Jaguar... etc. Those are usually easier to service.The ones with mechanical fans are usually the base models. Its a lot cheaper to make mechanical fan setups.

[subtle_driver]

Swapping an electric fan for mechanical is usually worth 10-25 HP and 1-2 mpg.

It is a very worthwhile trade but electric fans are a little less reliable (at least temp sensors are and fuses that go with the fan) and it requires a little extra engineering.

i don't know anyone on the board thats done it-I've always wanted to but. . .

If i'm bored, I'll test how much hp is lost from the mechanical fan, I'm going to the dyno in a few weeks again to see how much i have gained from the manual transmission swap.

here is a link to my fan setup.zer...78360
Modified by subtle_driver at 10:57 PM 4/7/2010

[Infinitiguy19]

almost every car that comes in my shop has an electric fan from the factory. Benz, BMW, Infiniti, Audi, Jaguar... etc. Those are usually easier to service.The ones with mechanical fans are usually the base models. Its a lot cheaper to make mechanical fan setups.

Up till 2002 The Q45 used a viscous fluid type fan. So I find it somewhat insulting that you reference the 1990-2001 Q45 as a "base model".

But anyways Electric fans provide very little gain if any VS the OEM fan:

http://www.aaroncake.net/rx-7/efanmyth.htm http://ecomodder.com/forum/sho....html http://dodgeforum.com/forum/1s....html

With a clutch fan you have FAR less to worry about because its a simple and dependable system. As far as I know (Knock on wood) no OEM fan has exploded.

Electric fans introduce far more problems for such a little gain. But it would be nice if you had before and after numbers on the dyno (With and without the OEM fan).

[Trumpkin]

no OEM fan has exploded.

Pretty bold statement. every part in a car will fail sooner or later. I have read numerous posts right here of members fan cracking and pulling apart. Mine did. In fact if your oe fan is old go look at it for cracking. Plus the guy who started this post said his needs done. go electric, I did.

[Infinitiguy19]

True but so far in the history of NICO and maybe even the Yahoo board the fan on a Q45 has stayed together.

Dennis's Q would be the real test.

[Q45tech]

I purchased a brand new fan assembly and viscous backin 2002 as part of the Q $13,000 overhaul. New ac system , new headlights, new subframe and diff..............everything that wore out after 200-240k.

As I keep pointing out the only components under the hood that are orginal are steering rack and pump, brake vacuum booster, engine block/heads, Cruise system, most harnesses and fuse blocks- backets and sheet metal.

In fact I noticed that the fan blades are cracking again [~100k].........too many 7,000 rpm shifts?

[subtle_driver]

True but so far in the history of NICO and maybe even the Yahoo board the fan on a Q45 has stayed together.

Dennis's Q would be the real test.

Not everyone posts on forums. I haven't posted all the modifications and results from my countless projects and customer cars.

I BLEW UP 2 factory plastic Fans and they cut up the radiator, 10 and 8 years ago. You can't say nobody has blown up a factory fan anymore. I installed electric fans since then and had no issues.

I love the free space and easy access when that mechanical fan is gone.

Don't get me wrong, the stock basic fan is great for grandpa or easy drivers. Does the job and performs better than most basic electric fans. but not for me. I work on my own car, i race my car, and i drive my car.

[subtle_driver]

Up till 2002 The Q45 used a viscous fluid type fan. So I find it somewhat insulting that you reference the 1990-2001 Q45 as a "base model".

I own a 1990 Q45, I'm not insulted that Nissan didn't use an electric fan. I love Base model cars! they are cheaper, faster, more simple, and lighter and have less probelms. I'm just happy to get rid of my cracked unit and install an electric fan instead.

"base model" is in reference to the benz or beemer that most costumers come in with. Occasionally I'll get the premium model with the electric fan.

if you're too lazy to click on my link to the previous post about this i made and got flamed for:

[Skibane]

Swapping an electric fan for mechanical is usually worth 10-25 HP

In order to move 25 horsepower worth of air with an electric fan, you'd need a fan motor that consumed roughly 30,000 watts (assuming 60 percent efficiency) - or around 2,200 amps at 13.8 volts.

Since 2,200 amps is about 2,100 amps more than the Q's alternator is capable of supplying, what does that tell you about the maximum engine cooling ability of an electric fan?

Or, look at it from another angle: A typical electric fan pulls 20 amps, which is 275 watts at 13.8 volts DC - which is about 0.2 horsepower (assuming 60 percent efficiency).

Do you really believe that 0.2 horsepower is enough to keep a Q's engine cool under all operating conditions?
Modified by Skibane at 9:05 PM 4/13/2010

[dsagers]

Another problem is the wimpy alternator on 90-93 cars, which can barely handle the factory systems electrical requirements.

[Infinitiguy19]

The stock fan is very efficient since it has a temperature controlled clutch my guess is it uses 3 HP at 6,000 rpm and maybe 1 HP at
2500 rpm. To make power for an electric fan the alternator must draw more HP from the engine thus you have the two additional
inefficiencies to contend with so it would be less efficient than direct drive under most conditions. Electric fans are used on front
wheel drive where the engine is sideways or where they want to shorten the space between the engine and radiator because of
packaging problems. Electric motors wear out much faster than direct driven units.....some LS400 uses hydraulic fan
motors driven from power steering pump. After 7 years the plastic blades do crack at the hub the under $100 blade is easy to replace!

By Q45Tech

Yes its a guess but this comes from a very smart man who has been around some time.

[bullittandy]

I've read numerous articles where people have removed clutch driven mechanical fans and dynoed the results and they are typically worth 10-15 HP, assuming that a older fan clutch is getting stiff it would not be hard to imagine it sucking up additional HP.

[elwesso]

the biggest thing I notice is when its really cold in the winter time, my car seems to run a little "cool".. I have a pretty new thermostat in the car (less than a year)...

I would say it would be worth it if you needed to do it for spacial reasons (turbos/SC?) but otherwise i doubt its worth it... $200 or more for a fan for a 1MPG overall difference would take a while to pay yourself back...

[1991q45]

subtle driver thats the same fan i have using as a condenser fan.
how did you hook yours up? the clutch is going on my q and the blades on my fan are cracked even more.