Clutch Fan Delete

[Threehz]

So I know there is a million ways to do the clutch fan delete, replace with electric fan, I'm just looking for some advice so I don't order the wrong things.

91' 318is, stock fan is just under 16" but the shroud will definitely fit a 16" fan + enclosure.

This is the fan I'm looking at getting http://www.spalusa.com/store/main.as...&item=30102120

CFM is 1918, will this be at least equivalent to the stock fan?\

I live in Tucson, AZ so in summer seeing 120 degree days won't be a surprise, on top of that, the air temperature coming up off the road/pavement reaches at least 130+ degrees

I'm not looking to do this mod to see any substantial HP gain, but instead to take some weight off my engine's shoulders.

From reading about this being done I plan on going about it like this:

Remove stock Aux fan

Remove clutch fan (what do you put in place where fan clutch is?)

Attach new 16" Spal fan to stock fan shroud, pulling of course

Wire new fan up to old Aux fan fuse connection

Wire E36 M44 temp sender to radiator (not sure about this part?)

Pray shit works?

Anyhow I'd really like some advice on this because not only is the summer hot as hell here, but that means using the AC full blast as well. The last thing I want is an underpowered cooling system. Thanks!

[Jaxx_]

it will work fine. there are 2 outputs for the aux fan, and if I'm not mistaken, there are 2 thermo switches on the radiator (to fire up the aux fan when you run hot).

If your fan is only going to be off/on (instead of off/low/high) you need to account for that. when your A/C gets turned on, the aux fan is designed to go to it's low setting. also, when one of the thermo switches hit a certain temperature, low is engaged. The other thermo switch is for the high output, and that's if your radiator is super super hot. I think OEM it's like 93C.

None the less, you can control it via an external switch, or let the thermo switches do the work for you. Make sure to test them before you rely on them, otherwise you'll end up with an overheating motor, and possibly a blown head gasket.

I only use the factory aux fan to cool my m10 and it's controlled through megasquirt, but the radiator switches are just as reliable. It pushes enough air for the m10, but probably not for 6 cyls working hard.


do you need a wiring diagram? you can use the factory relays to minimize the re-wiring.

[Threehz]

So that means that I can keep my regular aux fan and have my main electric fan running. I do have all the manuals for the car and the Chilton which is supposed to have the wiring diagrams hopefully I can figure it all out, right now I just want to make sure I don't order a fan that won't be strong enough.

So would I just wire up the new electric fan so it turns on when the aux fan would turn on low?

[smooth]

I only use the factory aux fan to cool my m10 and it's controlled through megasquirt, but the radiator switches are just as reliable. It pushes enough air for the m10, but probably not for 6 cyls working hard.

it's enough, that's all I have on my cabrio. I don't know if I'd trust it to idle in 120+ but I imagine so if everything is in order.

[stillkotd]

Ahem...

http://www.r3vlimited.com/board/showthread.php?t=210783

[Jaxx_]

So that means that I can keep my regular aux fan and have my main electric fan running. I do have all the manuals for the car and the Chilton which is supposed to have the wiring diagrams hopefully I can figure it all out, right now I just want to make sure I don't order a fan that won't be strong enough.

So would I just wire up the new electric fan so it turns on when the aux fan would turn on low?

I'm having a hard time understanding what you're trying to accomplish, exactly.

So I'll have a little binary table..

OEM fan: Off | Low | High
New fan: Off | ON  | ON

Do you want to keep the factory aux fan or not?

[jlevie]

I'm pretty sure that a ~2000CFM electric fan will weigh as much, if not more, than the stock fan+clutch. So no weight advantage there. You can ditch the aux fan for a weight savings, and only if, you also delete the A/C, which it doesn't sound like is in your plan.

The engine driven fan is responsible for engine cooling. The aux fan is there to provide additional air flow over the condensor and radiatior when A/C is in use and the car is idling or moving slowly. The stock fan and clutch is a simple system that is very effective and reliable if the parts (and waterpump) are in good condition. If the car will be driven in a hot environment and A/c will be used, both are necessary.

[Threehz]

Ahem...

http://www.r3vlimited.com/board/showthread.php?t=210783

Beautiful sir!

Jaxx, right on good sir.

Sounds like I want to keep the aux fan, and don't see why I wouldn't always good to have extra cooling out here in the desert.

Jlevie, don't know why you'd think I would be doing this for weight advantage?

The reason I'm doing this is to free up my engine from driving a ~16" fan at anywhere from 1000-7000 RPMs. I doubt it will give any noticeable HP increase, however I'm sure my engine will enjoy not having to drive that fan anymore.

Thanks for all the help guys, suppose I'll go with this fan and hope the electrical part is pretty straight forward.

[immajackuup]

http://forums.bimmerforums.com/forum/showthread.php?t=1737779&highlight=fan

this is all you need and the correct way of doing it,the very bottom is the correct diagram.

http://www.r3vlimited.com/board/showthread.php?t=232846&page=2

pic of my plug and play e36 electric fan.

The reason i did so it can free up my motor,no jet sound,and it won't damage my new 200 dollar radiator.

[jlevie]

Jlevie, don't know why you'd think I would be doing this for weight advantage?

Because you said "but instead to take some weight off my engine's shoulders."

The reason I'm doing this is to free up my engine from driving a ~16" fan at anywhere from 1000-7000 RPMs. I doubt it will give any noticeable HP increase, however I'm sure my engine will enjoy not having to drive that fan anymore.

Do you understand that the fan clutch is a viscous coupling that is temperature sensitive? The fan, because of the viscous clutch, will only rotate at engine speed when the engine is operating in the lower quarter of the rev band. As the engine speed increases the clutch slips and the fan turns much slower than the engine. And the clutch doesn't engage unless the air passing through the radiator is hot enough.

If you run the electric fan all the time, it will consume more power than the engine driven fan at car speeds where that matters. If you control the fan off the existing aux fan switches there are two problems. One is that the low temp switch is too high and the other is that the switches are mutually exclusive. When the low temp switch is on the high temp is off and when high temp switch is on the low temp switch is off. You can work around that with a pair of relays to control the electric fan, but that is more work and trouble than a standalone fan control.

The bottom line is that an electric fan on a street car makes no sense. It isn't a reliable as the engine driven fan, costs more with proper controls factored in, and has little to no affect on performance. We use them on race cars because even the slightest bit of performance is good and because the only time we need a fan at all is during a red flag incident or in the paddock. If the electric fan fails, and they do on occasion, it is no big deal. If your fan fails in stop and go traffic there is a good chance of an overheat and head or head gasket damage. A clutch driven fan degrades and gives you warning of impending failure, but an electric fan just quits.

[smooth]

The stock low temp switch is too high but you can use one that is rated lower and will turn the aux fan on at a lower temperature.

[jlevie]

The stock low temp switch is too high but you can use one that is rated lower and will turn the aux fan on at a lower temperature.

That is true, but you still need the high temp switch for the aux fan and the mutually exclusive characteristic of dual switches still applies.

[smooth]

Yes, I only use my aux fan. I don't have a second electric fan.
I really don't know whether my temps would stay under control where he's at but I only removed mine because the clutch was bad and I also witnessed someone losing a finger tip decades ago so I loath mechanical fans in general not just because I was bored.

I'm not really recommending he do this just mainly answering Jaxx' about whether it'd work for a 6 and also pointing out if he does go through with it he needs to get the lower temp switch.

[immajackuup]

1. Temp hits 80C. Radiator fan kicks on.
2. Temp hits 88C. Aux fan kicks on to supplement the radiator fan which it will never get to.
3. AC is turned on. Both fans come on.

this is the way i set mine up,my temp is always in the middle and the e36 fan only kick on a few time when idle in traffic.