Electric fans - Should we or not

[MagnusKK]

Hi guys,
We are considering putting electric fans on the car and would like to hear from you all if we should or not.

The reason we are considering it is because we dont see the viscous as the best solution and feel its sucking too much in terms of space and using too much oomph from the engine.
On the other hand I dont know what the negatives are in terms of strain to the alternator and overall the electric system the electric fans have.
I see though a benefit in space saving and potential for the electric fans.
I also dont know if by using electric fans I should can the shroud. I feel the sroud plays a possitive role in airflow through the ratiator.......Is that true?

Can I hear some opinions and maybe reccomend me some kits ( that include everything)?

Just for reference the engine is fully rebuild to OEM 2.3 specs (just Lightweight flywheel and the new Vac balancer) but in the future will most likely get cams, intake and a remap and we will retain the AC.
It has everything new, including radiator and even a new viscous at the moment and its meant to be a garage queen and not a track car so no crazy mods. Just want to upgrade/update small things in order to acheive a better than OEM feel on the car.
Any constractive suggestions or comments are welcome as I really am at a cross road here.....

[hardtailer]

Go electric and remove the viscous fan. It's how all euro cars, including your Europameister came from the factory.

Stock works great. Replace the resistor for low fan speed with a new generic 5W 0.5Ohm one for a fraction of the price of the BMW part.

[Dave @nz]

I think the viscous fan and shroud went on as part installation of the A/C kit and I would be very cautious about removing it unless you have 100% confidence that the electrical fan will always go when the A/C clutch is engaged (it should anyway on low speed).

[MagnusKK]

Go electric and remove the viscous fan. It's how all euro cars, including your Europameister came from the factory.

Stock works great. Replace the resistor for low fan speed with a new generic 5W 0.5Ohm one for a fraction of the price of the BMW part.

I have never seen an electric one from factory, Unless you mean the auxilary fan

[Ron ///Man]

All of your points are spot-on in my opinion, for a track car. For a street car with A/C, I agree with Dave that you should proceed with caution. Not only do you need to make sure the electric fan comes on when the AC is engqged, you need to make sure the electric fan is sized properly to move enough air to cool the engine and the AC condenser as well. I ditched my viscous fan years ago in favor of a puller curved blade electric fan that I mounted in the shroud in my race cars. I discovered there are several different fan configurations that move differing amounts of air plus some are pusher fans and some are puller fans. Puller fans are the most efficient at cooling. Choosing the right size electric fan can be a crap shoot since we don't know how many CFM of air the viscous fan moves, and, how many CFM of air the Aux fan moves when the AC is engaged. If you just go for the biggest one you can find, it will probably work, but, it will take a lot of power to run it. The model fan I use is the same diameter as the stock fan, so it fits nicely in the shroud opening. The shroud is very important to draw air through the entire radiator. If you just mount the fan to the radiator face, you only pull air through the area in front of the fan. The rest of the radiator relies on natural air flow which only works when you're moving. I'm quite happy with the way mine work on my race cars. They keep my water at 185 deg when I'm racing in all kinds of weather.

[jimmy p.]

I have never seen an electric one from factory, Unless you mean the auxilary fan

What many people call the "Aux Fan" is really "The Fan".
The Viscous fan is the added on fan this making it the real "Aux Fan".
The non AC cars only came with the electric fan.

I have only the factory BMW electric fan on both my race cars on the standard BMW non-AC brackets.
My street cars only have viscous fans on them (neither has AC anymore). Eventually I will get them both on the euro Non AC brackets, I'm just being lazy for the past 20+ years

[hardtailer]

I have never seen an electric one from factory, Unless you mean the auxilary fan

We're meaning the same thing, like Jimmy already pointed out.
My euro, non-A/C M3 has only the electric fan, all 4 different 320is'es I've owned had AC and they too only had this electric fan that was identical to the one on the M3 apart from the brackets.
Now, I hear you thinking 'but those are 2.0 and the M3 is a 2.3l engine'. Yes, indeed but still the Euro M3's with A/C only ever had an electric fan but no viscous fan from factory.

On A/C cars the fan turns at full speed as soon as you switch the A/C on, so there really is no reason to deviate from stock and only run the electric fan on your Europameister.

ETA:
Going by the picture in your thread about restoring the Europameister it seems to me you fitted a puller fan instead of the stock fan (which is a pushing fan).
Yours should be fitted behind the radiator or replaced by a pushing fan.

[hardtailer]

I checked pictures of mine and my point above is NOT valid.
The fan turns clockwise and as such air is pushed through the A/C condenser and the radiator.

[jimmy p.]

I read a post somewhere that described the reasoning and conditions that applied to cars like the north american cars that got the viscous fan. I wish I could find it, it was informative. I think it had to do with places that had potential for hotter climates than say continental Europe got the added viscous fan but something along the lines that they didnt feel it was needed in Europe.
It was a good post, cant remember where I read it.

[MagnusKK]

We're meaning the same thing, like Jimmy already pointed out.
My euro, non-A/C M3 has only the electric fan, all 4 different 320is'es I've owned had AC and they too only had this electric fan that was identical to the one on the M3 apart from the brackets.
Now, I hear you thinking 'but those are 2.0 and the M3 is a 2.3l engine'. Yes, indeed but still the Euro M3's with A/C only ever had an electric fan but no viscous fan from factory.

On A/C cars the fan turns at full speed as soon as you switch the A/C on, so there really is no reason to deviate from stock and only run the electric fan on your Europameister.

ETA:
Going by the picture in your thread about restoring the Europameister it seems to me you fitted a puller fan instead of the stock fan (which is a pushing fan).
Yours should be fitted behind the radiator or replaced by a pushing fan.

THe one on the pic is the AC one and it was like that from stock

[erikm54life]

I remember my friend in the UK ( Darren Farrell ) ,who is also an M expert, state that the viscous fan on AC cars should be left in place. His reasoning was that in addition to extracting heat from the radiator it also helps in eliminating localized hot spots within the cylinder head. In a hot climate such as mine it would be suicide.....the system as it is, with the AC on, struggles to keep the temp within its acceptable range.

[weisen]

One question on this topic. My 320is with AC came from factory for the Italian market without the viscous fan. It has a two speed electric fan. The fan is always on with AC, when the temperature exceeds a certain threshold, it goes on high speed. This also happens when AC is off. This is all controlled by relais and a temp sensor close to the fan. It works perfectly fine here in Germany even with high temperatures and I guess it worked fine in Italy as well. Did BMW sell the setup with the viscous fan for "hot" markets like California, UAE or Japan?

[jimmy p.]

One question on this topic. My 320is with AC came from factory for the Italian market without the viscous fan. It has a two speed electric fan. The fan is always on with AC, when the temperature exceeds a certain threshold, it goes on high speed. This also happens when AC is off. This is all controlled by relais and a temp sensor close to the fan. It works perfectly fine here in Germany even with high temperatures and I guess it worked fine in Italy as well. Did BMW sell the setup with the viscous fan for "hot" markets like California, UAE or Japan?

Yeah that was the reasoning that I read. There was a metric for which the cars / markets received the additional viscous fan. I wish I could find the post (or the time to hunt it down more so).