Fan Delete Mod?????

[NeverLeaned]

Well, next weekend, weather permitting, I plan on going to the next phase of my project bimmer

So the project includes installing my new underdrive pulley system. While Im in there, Im also gonna replace the waterpump (not sure if I have that dreaded plastic impeller or not ), flush coolant system.

Since Im gonna have all of this apart, I started looking into the fan delete mod as well. Could make myself a nice 8-15 ponies in one days worth of work

Anyways, there wasn't much out there in terms of DIY's on the fan delete. I assume its pretty straightforwards anyways.... I've done this to before.

This is the only DIY I came across
http://www.ohiomotorcycle.com/unders...lutchmod.shtml

soooo, I read this article 3 times and I quote

Removing the driven fan does reduce the cooling efficiency somewhat, but only while the car is moving less than about 10MPH. However by lowering the thermostat temperature, using Red Line Water Wetter and by using a lower temperature fan switch the risk of overheating is eliminated. It is advised that those running forced induction or living in very hot areas of the country (southern FL, AZ, etc) either skip this mod or add an additional high CFM aftermarket electric fan.

So, they are basically recommending to not even bother installing an electric fan???? The effect of the water wetter and lower temp thermostat is enough to offest?

Anyone here do a fan delete and NOT install an electric fan behind the radiator? The electric fan in the front is enough?

[Brian325i]

So are we talking about removing the fan that's connected to the water pump? What about the fan in front of the radiator...is it possible to delete that fan as well or is that one already electric?

[NeverLeaned]

The removal of the fan and fan clutch attached to the water pump is what the mod is all about. The electric fan in front of the radiator remains....

I need to do some research on what exactly the front electric fan does (I assumed it was only activated in conjunction with the A/C)

[Speedy-325is]

i think uuc motorwerkes has a step by step on the fan delete w/the exact switch u need for the electric fan....

Mark

correction: understeer, not uuc. thanks for the help Neverleaned.

[Brian325i]

Let me know what you find, I am going to be changing out my water pump, thermo(have a 75C thermo coming this week), and flushing out the radiator this coming weekend. As well as changing the hoses and thermo housing. I am going to be using water wetter with some bmw antifreeze + distilled water...anyone have any good experiences with a certain ratio?

[NeverLeaned]

Originally posted by Brian325i@Oct 5 2004, 10:55 PM
Let me know what you find, I am going to be changing out my water pump, thermo(have a 75C thermo coming this week), and flushing out the radiator this coming weekend. As well as changing the hoses and thermo housing. I am going to be using water wetter with some bmw antifreeze + distilled water...anyone have any good experiences with a certain ratio?

[snapback]205747[/snapback]

Here ya go Brian,
http://www.bmw-forums.com/forum/index.php?...topic=23180&hl=

Our latest discussion on the topic. (lots of links)

Here is also an excellent reference (this is actually the baseline for my method)
http://www.racerpartswholesale.com/redtech3.htm

Cutting to the point here, Water is actually the best transfer of heat..... so the higher the ratio of water to antifreeze the better (of course within the reason.... too lean of a mixture will result in freezing!)

There is a great chart in the article showing the effects of engine temperature on torque (the base car was a BMW)

I plan on using a 65%W 35%antifreeze mix with the water wetter. Seems to be the 'safest' concentration of antifreeze to ensure safe winter operation.

understeer.com recommends a 80C thermostat (so it looks like your safe there) If you read the article they actually list all the part numbers required (including the fan switch) They also sell a kit for the conversion http://www.ohiomotorcycle.com/understeer/o...re-engine.shtml
$90 seems a little steep for a thermostat, fan switch, and some gaskets IMHO though. (but you can use all the part numbers to hunt the correct materials you need to do it)

NL

[Brian325i]

Awesome, 65/35 looks like a good mix. I don't quite get the fan delete part though. Your supposed to take the engine ran fan off I know but are you supposed to put an electric one in it's place or just not have a fan there at all. It seems like that kit is making it so you can turn on an electric fan whenever needed...but I thought that was the thermostat's job. If I need an electric fan to replace the engine powered one...where are we supposed to get that? Heh I already saw that forum discussion, I stated that I was thinking of going 70/30 with WW.

[NeverLeaned]

Originally posted by Brian325i@Oct 5 2004, 11:48 PM
Awesome, 65/35 looks like a good mix. I don't quite get the fan delete part though. Your supposed to take the engine ran fan off I know but are you supposed to put an electric one in it's place or just not have a fan there at all. It seems like that kit is making it so you can turn on an electric fan whenever needed...but I thought that was the thermostat's job. If I need an electric fan to replace the engine powered one...where are we supposed to get that? Heh I already saw that forum discussion, I stated that I was thinking of going 70/30 with WW.

[snapback]205775[/snapback]

The DIY is suggesting to only go with the front electric fan. (they only suggest installing another electric fan (behind radiator) if you live in high temp areas.

The fan switch is not manual. (this switch is for the front electric fan) By replacing the current switch with a lower temp one it will cause your front electric fan to come on at a lower temp.

I read somewhere that flex-a-lite makes a low profile electric fan that will fit behind the radiator if you are inclined to install it.

[Bear]

You can take the viscous fan off and run with the auxilary fan (the one at the radiator) but, if I were to do this I would buy the low temp fan switch from BAV AUTO or BMP that activates the auxilary fan sooner.

[Bear]

Sorry, I got interuppted, but the auxilary fan runs under two conditions:

1. Anytime AC is sleected.

2. Whenever the temperature satisfies the auxilary fan switch (screwed in to side of radiator), on my E32 that is at 91 degrees "C" for low speed and 99 degrees "C" for high speed. I am not familiar with your car (series) so I do not know if your fan switch is one or two speed, but the modified ones I mention run at 81 Degrees "C" and 88 degress "C".

[Brian325i]

Well I just ordered some parts from bavauto not too long ago and I don't want to spend the minimum $8 on shipping just for the switch. I guess I'll wait until I need some more stuff from bavauto or look on ebay...I think I'll hold off on the fan delete mod, shouldn't be too hard to get the fan back off once I take it off to replace the water pump, thanks guys.

[NeverLeaned]

Originally posted by Brian325i@Oct 6 2004, 02:44 PM
Well I just ordered some parts from bavauto not too long ago and I don't want to spend the minimum $8 on shipping just for the switch. I guess I'll wait until I need some more stuff from bavauto or look on ebay...I think I'll hold off on the fan delete mod, shouldn't be too hard to get the fan back off once I take it off to replace the water pump, thanks guys.

[snapback]206211[/snapback]

I can't find the fan switch that they recommend on Bav auto. Only the stock one. I've managed to find all the parts accept for that one. If I can find it, then I don't have to worry about paying $90 for that kit that really should be $60.

Here's the part number
61 31 8 376 440

Any ideas on where to look?

NL

[Brian325i]

I thought I saw a fan switch on bav that was the 80-88C one...is that the one you're looking for? Just search for fan switch.

[NeverLeaned]

When I do a search only fan switch comes up. There is no details on what it is. Guess I will call them tomorrow.

At least it gave me the ideal of what this is really gonna cost me.
Thermostat ~30
Fan Switch ~35
Water Wetter ~15
Misc. gaskets ~10

Which is basically the price of the kit offered by understeer. I'll do a bit more hunting tomorrow, but unless Im gonna save $20 I will probably just order the $90 kit from one place.

If you really think about it........................

Its not a bad price for 6 more ponies....
$90 for the kit
or you can say its a $75 upgrade--- minus $15 for Water Wetter (if your gonna change your anti-freeze anyways)
or you can say its a $45 upgrade ---minus $45 for Water Wetter/thermostat (if you have to change your thermostat anyways)

I believe I will use last one to justify this mod

[Brian325i]

Do I need the water pump Thread cap?...this part goes where the fan used to be, right?