electric fan

KimiG · Post by **KimiG** » Sat Apr 07, 2007 8:21 am

Hey guys
I would like to fit electric fans. Please can I get some advice on what fans to get and if its worth doing the conversion... Could I do the job myself and what else other than the fan needs to be done and purchased??

Any advice will be appreciated

Ero_sennin · Post by **Ero_sennin** » Sat Apr 07, 2007 10:01 am

http://www.200sx.za.net/phpBB2/viewtopi ... an&start=0

Search and ye shall find

The Calibrator · Post by **The Calibrator** » Sat Apr 07, 2007 5:12 pm

IMHO if the std stuff is working fine then leave it alone. Changing to electric fans just for the sake of it is a waste of money and leads to other issues.

Phinx · Post by **Phinx** » Sun Apr 08, 2007 6:26 pm

I'm going with "The Calibrator"

On this, I have had nothing but sh$t with my electric fan swap.

veecee · Post by **veecee** » Sun Apr 08, 2007 6:36 pm

let me be the one to start the argument again!

my electric fan swap has been nothing but fine. i've installed two 12 inch electric fans, they are switched by a bmw switch (available from spares dealers) that switches at two temperatures - 91 and 99.

originally i had one fan switched at 91 degrees, and the other at 99 degrees. then i had one switched on at 91 degrees, and the other by the aircon switch. now i'm switching both fans at 91 degrees.

BUT - i've removed my aircon system. thats the aircon radiator, piping and compressor. so my car seems to be running about 10-15 degrees cooler than it used to with that stuff installed.

however, mine is a different case study, and i've heard of other members not having enough CFM on the fans to cool sufficiently. so others have definitely had problems with this mod.

i've also modified my water housing to accept the BMW switch and the temp gauge sender unit. so things are different to standard when it comes to my engine!!!

WooHaa · Post by **WooHaa** » Sun Apr 08, 2007 6:47 pm

Okay let me add my 2cents worth.
The thing to consider is that the viscous fan runs continously & the temperature of the car is controlled via thermostat.
So if you are adding electric fans, I suggest you ran the fans continous anyway.

Another thing to consider is that the standard fan is designed to shift a certain amount of air, so the electric fans should be able to shift more or the same.

All the eletric fan does, is really add more to the throttle response. The power is increased, but by a very slight fraction.

I had electic fans on my old SX without a problem & now I have the viscous fan on my current SX without a problem.

veecee · Post by **veecee** » Sun Apr 08, 2007 7:10 pm

WooHaa wrote:Okay let me add my 2cents worth.
The thing to consider is that the viscous fan runs continously

the viscous fan shouldn't be running continuously. it is connected to a viscous coupling. the material that fills the coupling gets more viscous the hotter it gets. so the temperature under the bonnet controls the amount that the fans turns. its basically a clutch!!! one that engages more the hotter the engine gets.

when its cold, it shouldnt be running much at all. i've seen cars that barely spin when the viscous coupling is cold, and you can stop the fan blades with your bare hands!!!

mine was running all the time, and that is why i replaced it with electric fans!!! its not supposed to run like that.

as for throttle response, unless your "butt dyno" is tuned way better than phinx's, you probably wont feel the difference... unless you're one of those guys that immediately thinks that the improvement in sound that their drilled airbox now makes, is a definite 10 - 15kw's on their little FWD slopel or golfie wheels!!!!!!!

hehehe - now that should summon a myriad of response!!!

WooHaa · Post by **WooHaa** » Sun Apr 08, 2007 7:40 pm

O!!
My fans spins all the time. Even when it's very cold, & not slowly either.

You are worrying me a little here. The car has always been like this. I have seen other cars like mine as well (SX's) when you start the car from cold it spins quite fast...Don't think I wanna put my hands there.

Is anybody else's like mine as well? Maybe I should record a video & show you guys.

The fan is very quite but spins fast, The bearings don't make a noise & the fan doesn't wobble.

What you are saying is correct about a clutch & all that, but the SX does'nt have that. It should spin all the time as the temp of the engine is thermostat controlled. If you want to drop the engine temp, you don't spin the fan faster, you change the thermostat.

veecee · Post by **veecee** » Sun Apr 08, 2007 8:09 pm

yeah my sx did that too... that's why i changed it to electric fans.

but my experience with other vehicles is that a VISCOUS coupling does just that. as it gets hotter it offers more resistance between the plates(?) so the fan starts spinning more.

it may not be the case with the sx, but as far as i know, a viscous coupling is what i just described. otherwise they shouldn't call it that.

also a thermostat is there to control temperatures, yes... but its there only to get the engine temperature up to operating specs quickly. it stops water flowing to the radiator at low temps, so that the engine warms up quickly, then it opens to allow water to the radiator, to keep the operating temperature constant.

thats also why you dont need the fan(s) to operate at low temps. because at low temperatures, if you have a correctly operating thermostat, the water wont even be running through the radiator!!!

a good test is to remove the thermostat and see at what temperature it opens. you can do this by placing it in a pot on hte stove, with a thermometer in it!!! check the temperature at which it opens. chances are its between 80 and 90.

so why bother using a fan to cool a radiator that isnt even involved in the flow of water until the engine temperature gets to between 80 and 90 degrees???

WooHaa · Post by **WooHaa** » Sun Apr 08, 2007 9:45 pm

You are 100% correct VC, but the reason that Nissan & other cars like the 230 Kompressor run the fans continuosly, is because the water is used to cool the oil as well.
The themostat just controls water temp to the engine.
If the fans are used to control water temp only, then the oil temp gets to high.

I have had the oil get so thin it leaked through the seals of my turbo on my previous Nissan...Luckily no damage was caused.

I have noticed higher performance cars, run fans all the time, just for the above reason.

veecee · Post by **veecee** » Sun Apr 08, 2007 10:10 pm

LOL - yeah you're also right.

actually this is quite constructive, cos i forgot about that totally. guess i'll go out and buy that oil cooler now!!! forgot that the nissans have that highly effective oil "heater" on our CA18det's!!!

but that also brings me to another mod that i wanted to do. and thats install an LED in dash to let me know when the fans are on, and install an override switch to turn the fans permanently on when i am drifting.

Desertrat · Post by **Desertrat** » Sun Apr 08, 2007 10:59 pm

I have had electric fans for about 6 months and they work wonderfully. I have to add that my old fan got stuck in the on position, so the electric fans made a performance diff since it spun with up to 7000rpm where it is supposed to start slipping at about 2500-3000rpm.

The Calibrator · Post by **The Calibrator** » Mon Apr 09, 2007 10:33 am

I have seen a few of these fans mods with the switch in the thermostat housing and its a fuckup.
How can you possibly control the engine temp when you are using the COLD water from the radiatior to switch the fans?
If you are switching at 91deg on the cold side how hot is the inlet into the radiator?
Yes I know that BMW's switch on the cold side but that is because they only want to use the electric fan when the viscous is not coping

the viscous fan shouldn't be running continuously. it is connected to a viscous coupling. the material that fills the coupling gets more viscous the hotter it gets. so the temperature under the bonnet controls the amount that the fans turns. its basically a clutch!!! one that engages more the hotter the engine gets.

I beg to differ about this complicated explanation.I have heard this theory before but in 25 years in the motor industry and I have NEVER seen a viscous bhave in this manner.

A viscous coupling can transmit a certain amount of force before the silicone paste "shears".
This allows the fan to turn when the car is driving slowly but lets it slip at hway speeds when it is not required.

If you rev the engine up slowly you will see and hear the fan start slowing down at about 2500 to 3000 rpm.

Desertrat · Post by **Desertrat** » Mon Apr 09, 2007 11:08 am

i agree with cal... all you have to do is make sure your temp senser on the intake side of the radiator.

widowmaker · Post by **widowmaker** » Mon Apr 09, 2007 4:32 pm

interesting stuff, but then at what RPMs can I stick my fingers into it?

or is it the difference between the engine power and the force of the incoming wind at speed battling it out?

still seems like a loss of power to me...

maybe we just shouldn't drive slowly and take the fan out completely

what about using an oil temp sensor instead?