"Fan delete mod"

[guibo09]

Point taken. But the whole "less drag on engine" doesn't really apply to our motors.

why not?

[Brew]

Why are people hatin up on clutch fans???

Unless clearance is the issue, clutch fans are awesome. I've seen 500-600 2jz's and rb25's still running clutch fans w/ no problems. Why get rid of what the BMW engineers spent millions researching for??

Just my 2cents

They fail all the time on BMWs, and when they do, they provide almost no cooling or throw the fan into the radiator or hoses.

[MDryVur]

imagine e30s had fan clutches like the old 350 motors or the 402 motors. hahahahaha metal blades.

[Victell]

Why are people hatin up on clutch fans???

Unless clearance is the issue, clutch fans are awesome. I've seen 500-600 2jz's and rb25's still running clutch fans w/ no problems. Why get rid of what the BMW engineers spent millions researching for??

Depends on what kind of fan clutch it is. Anybody know if its an RPM or temperature based clutch? Cus if its the type of clutch that freewheels at higher rpm, then its worth keeping.

No use taking rotating mechanical energy, changing it into electrical energy, then back in to rotational again for an electric fan.

which reminds me, need to figure out how do turn off the alternator at wot.

[nando]

if you use a thermoswitch to turn on your fan, it's NEVER going to be turned on at WOT. You have to be sitting in traffic at a dead stop for 10 minutes for it to turn on, as soon as you start moving air flow through the radiator is enough to keep it cool. a load is not going to be on your alternator.

[SpecM]

which reminds me, need to figure out how do turn off the alternator at wot.

and that's a bad idea

if you reduce the battery charge from around 14.5v to 12v (and falling...), you also reduce the effecientcy of the coils to produce spark.... not so good for WOT

[graphikg]

Can this mod be done to 5 series m50s?

[nando]

and that's a bad idea

if you reduce the battery charge from around 14.5v to 12v (and falling...), you also reduce the effecientcy of the coils to produce spark.... not so good for WOT

it also changes the injector dead time, and the car will run leaner.

[Victell]

and that's a bad idea

if you reduce the battery charge from around 14.5v to 12v (and falling...), you also reduce the effecientcy of the coils to produce spark.... not so good for WOT

Battery voltage will stay at alternator charging voltage for quite a while before it drops. Certainly will stay at 14.5 or whatever for the seconds you're at wot. Coils and injectors will be fine.

Alternator cut-off is not my idea. Some new vehicle, 09 or 10 model is setup where the alternator only charges when the vehicle is not under load. I forget which one, but its not a hybrid car.

[LowR3V'in]

Only reason why you'd want to get
an electric fan vs clutch.

That was my 2nd fan too.
Would flex so bad it hit the
hose that was already zip tied. WP Broke while racing. :(

[nando]

if it hit your hoses then something was broken or missing - motor mounts, the clips that hold the hoses to the motor, etc.

[vr2jetta]

So I have a late model, and the fan went bad. I replaced it with an early model fan, which works, but now there are a couple late models that just came into the junkyard with apparently good fans. Should I swap the old style 5 blade fan for the newer style ?13? blade fan? If so, should I consider mounting the old style fan to the back of the radiator to assist in cooling? I want to run a/c with no problems and it gets hot here in FL.

[flyboyx]

So I have a late model, and the fan went bad. I replaced it with an early model fan, which works, but now there are a couple late models that just came into the junkyard with apparently good fans. Should I swap the old style 5 blade fan for the newer style ?13? blade fan? If so, should I consider mounting the old style fan to the back of the radiator to assist in cooling? I want to run a/c with no problems and it gets hot here in FL.

here is my suggestion:

this is an excerpt from my obd2 swap thread listed here. i used the factory bmw electric fan out of a 750i. since these cars are pretty tough to come by, you may also be able to use the fan out of a 740i from the early 90's (ish). don't get the fan that includes its own rectangular shroud. that one will not fit.

here is a comparison pic of the late style e30 a/c fan next to the one from a 750il. as you can see, the blades are a completely different style. even though it looks like they should spin on opposite directions, both are designed to spin clockwise



i finished up my cooling fan and took a few photos in the event someone else would like to use the same system. since the 750iL fan is about 3 or 4 inches larger in diameter, the condenser brackets had to be changed to make it work. i cut the bracket off the top of the condenser and welded it to a reshaped lower bracket on the passenger side of the car.


my solution to make this fan fit was to rotate it about 60 degrees clockwise. that puts the upper right mount at the 360 degree position. i cut out some of the metal on the bottom of the upper core support because the diameter of the fan is too large to fit in the core support opening. this also gave me a good solid place to mount the top bolt.





the third mount was a little more complicated. i had to fabricate a bracket to secure it properly to the condenser. i folded the original mounting point flat and bolted the top part of my fabricated bracket to that point. i welded to the bottom condenser mount but that probably wasn't necessary. two #8 bolts would have worked if you don't have access to a welder.



here is a pic with the fan installed. it pretty much takes up the opening in the core support plus another inch.



this is a closeup of the top of the fan installed in the opening i cut in the underside of the upper core support



finally, the wiring pigtail on the 750i fan is really short. my solution was to cut the pigtail off my old fan and also about a foot and a half of the wiring from one my parts cars. they are spliced together under the black plastic sheath.



for me, this solution was a lot cheaper than the spal that most everyone uses. from an electrical standpoint, i think it is a better choice because it is a factory part that you can just extend the wiring and plug in. also, like the e30 fan, it comes with the three wire design with resistor so you get two speeds just like a factory fan. i have not run it yet to test it, but i think it will do a good job of keeping my engine cool. it may also allow me to use my m42 radiator so i can eliminate the reservoir on my driver side fender well.

this morning before i started my trip, i tested out the aux fan circuit. to do this, i turned on the ignition and jumper-ed the circuit at the three prong radiator switch. low speed worked great, but high speed blew the fuse. after cross referencing, i found the number three fuse that i blew is actually for low speed. it turns out that the high and low wires in the 750i fan are in opposite positions compared to the e30. good news with this plug: it can be taken apart very easily. all you have to do is slide the tie wrap off the connector, open up the plastic retainer, and swap terminals to the correct position. when the high speed circuit is connected, that thing will really blow some serious air! now that it is tested and i know it works, i feel really confident that all of my cooling issues are taken care of.

[mega_t2008]

Hi guys.
In my friend's E30 M50B25Tu there is a thermostat opens by 87 C, and Electric fan from Mercedes W210, with some modifications and it never starts when the car is driving 50+ km/h. Engine temp is OK, and I don't understand why to go with lower thermostat because engine work temperature is 85-90C. And the factory thermostat for Europe is 87C...
Here is the fan:


It is a little bit noisy but in less then 30 sec temp goes from 90 to 80 C. :)

[3bvert]

so far this is my first winter with an electric fan only, and it has not kicked on in days and days. I think in winter another side benefit might be that the engine warms up faster, thus the heater does too