Best electric cooling fan improvement for a 6er

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Da_Hose
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Best electric cooling fan improvement for a 6er

Post by Da_Hose »

Ok, people. I am having heat issues on 100+ degree days when running the A/C in town. I want to have the absolutely most powerful fan I can cram in the space in front of the radiator and A/C condenser. I am not even worried about it lasting a lifetime. I just want the most air flow I can get. Being too cold will NEVER be an issue here in CA, but I could put a thermal sensor on it if necessary. I plan to wire it directly to the battery/starter terminal and the existing fan power lead will only operate a relay.

So then. Who has installed an insanely powerful fan up front that they would recommend for my Brünhilde?

Jose
1987 M6 - My dream car
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Post by jacko »

I'm thinking it's both a function of the fan output and a well designed shroud. Just having the fan adressing only a part of the condenser seems like an inefficient idea. I'm waiting until the e39 fan shows up and then sizing the condenser to fit it's shroud.
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Post by Da_Hose »

Can you even get fans without integrated shrouds? I hadn't considered replacing just the fan in my existing housing. I figured the best case would be a refresh of the existing fan.

I do intend to replace the whole thing a la E39 fan. Definitely post up how the E39 fan works for you, Jacko.

Jose
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Post by jacko »

Jose, does your factory condenser fan have a shroud? All mine has is a ring.

Another think I wonder is why does the condenser mount flush to the radiator?
Why not cant the bottom out?
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Post by Da_Hose »

If the bottom canted out on the condenser, then the air wouldn't move freely through the radiator.

My existing fan is the OEM model (metal fan inside a ring). It looks very cool and old school, but it just doesn't move enough air at city speeds. A high power fan wouldn't just help the A/C, it will help the car radiator cool the engine on these really hot California summers, when I'm putting around the downtown area.

Jose
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Post by jacko »

Here in Texas too. We went to Florida to escape the heat! :-)
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Post by Da_Hose »

Over in Texas you guys get CRAZY hot summers. We hover in the 90+ degree range a lot, but we definitely get a few 100+ degree days as well. This week, the thermometer in my OBD panel was registering 115.

Jose
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Post by jps635 »

Hi Jose

I removed my air con and replaced both fans with this https://daviescraig.com.au/product/dcsl ... rt-no-0066

Designed for V8's and diesels - very powerful. When running, and you step out the car, you can feel a strong breeze under the car pushing out heat. Operation is governed by a thermatic temp switch which you can infinitely calibrate and set up so it holds 90 deg (Stack gauge reading off the spare thermostat housing sensor probe).

I've also got 2 manual switches, one to turn on fan at any time engine is running and another that runs the fan through an adjustable timer with ignition off.

Gaz also has this set up but with his air con. He lives in Queensland where it gets stinking hot so better to talk to him wrt air-con cooling.

Chris
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Post by Da_Hose »

So Chris, are you are running a single DCSL16, or you are running dual in a push/pull?

Based on the brutal duty you and Gaz are putting it through, that fan sounds like exactly what I want.

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Post by ericono »

Chris,

Got any pictures of that set up? Sounds like it is working well for you.

Thanks,

Eric
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Post by jps635 »

Posted some pics as best I could take.

Fan is 16" pusher, not enough clearance for a puller. I fabricated a bracket out of alum. angle to support the weight rather than mount solely on the core, and only used 2 through core mounts at topto prevent forward and aft movement.. Bracket bolts to the front cross member.

There are four relays. One is for the timer. The relay attached to the front of the fuse box stops the fan illuminating the warning light when driven by car speed. (I used the cluster pad wear warning light to illuminate when running). Other 2 relays come with the kit. Left my original wiring in place.

Chris
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Post by ericono »

Nice setup. Are you still running the mechanical fan or did you remove that?

Thanks again,

Eric
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Post by Da_Hose »

Looks like Flex-a-lite makes a 16" fan that has even more output than the DCSL16, but holds to about the same dimensions. I ordered up a Syclone 398 fan with a 180 degree thermostat and relay control kit.

Do we think it would be best to just plug the power lead from the old fan into the relay and rely on the existing sensors?

Or would it be better to simply disconnect/label the old power connection and rely on the thermostat I ordered? I would plug the relay into an ignition controlled wire.

Jose
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Post by GazM3 »

I got a 16" crag Daivies fan also with their controller getting power from the original thermostat switch off the radiator.

I have the tropical 38core radiator and importantly I have used some closed sell foam to make a seal from the condenser to the radiator itself. All the clutch fan and shroud are removed.

I have no functioning ac(still) which may make a difference. The hottest I see ok the temp gauge is about 5/8 when idling a long time. On the move it never sits much higher than 3/8. It seems te m88 cooling system seems to have been designed for racing as the harder I drive it the cooler it seems to run. I guess the sensors are right above the exhaust which makes the temp spike when sitting idle. As soon as I move away within 10sec the temp gauge instantly moves back to about 3/8 even if it's been idle for a while.

When this engine upgrade happens I may have to go to an upgraded radiator and /or remove the condenser if I'm not going to bother connecting the AC to help deal with the extra heat.
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Post by Da_Hose »

Take a look at the Flex a Lite web site, Gaz. They sell some shrouded fans designed for close fit to the radiator. If you won't have a condenser, then you could get the biggest that will fit and those things are rated at 3500+ CFM.

Jose
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Post by Da_Hose »

Well ........ I did some more testing and what I see makes no sense.

First, whoever put in the radiator before me did not put the sensors back where they belong. The dual temp. sensor is supposed to be on the bottom and the compressor temp. sensor is supposed to be on top. I will switch that around this weekend.

What doesn't make sense though, is that the engine never got above 130 degrees at the sensor or the radiator (I have a heat sensor gun), but the fan starts running as soon as I set the ignition to "Run". Pulling the K6 relay stops the fan, so clearly the high speed relay is being energized.

The wires at the sensor have clearly been tampered with and sure enough, I measure 12V on both of the grn/blk wires, but the blue wire has no voltage at all.

So then, my guess is that the OEM temp sensor doesn't get hot enough to trigger the fan when the sensor is on the intake side of the radiator, so whoever converted the car to R134 has shorted the wires of the high speed relay circuit and the condenser fan is getting full 12V at all times. That is a pretty ham fisted way to do things and I'm sure it's because the condenser was not upgraded at the time the whole system was re-done.

Thinking hard about how I WANT things to operate, the engine can run cool in the winter and I absolutely don't need the extra fan if it's not getting above the 1/3 point. In the summer, it never runs below 1/3 and I will always want the condenser fan running, regardless of whether or not I'm running the A/C.

I suppose the right thing to do is ...

1.) Figure out where the friggin wiring harness was shorted and restore normal operation, but leave the sensor unplugged.

2.) Make a jumper for the 12V lead that feeds the original temp sensor and use it to send power to the adjustable thermal relay I purchased.

3.) Adjust the new relay so that when engine temp. is above 1/3 of normal, it sends power to the original high speed fan circuit. Just leave the low speed fan circuit disconnected.

4.) Run the new fan with the original, high speed power lead because it has a dedicated 30A feed.

Jose
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fan upgrade

Post by JCS »

Here is a link to a fan upgrade from an e39

viewtopic.php?t=9987&highlight=

The OBC reads the temperature of the pavement, and is used for ICEY roads, not the real temp outside
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Post by Da_Hose »

I installed the new fan and can report that on a day when it was 100 degrees outside, I still had cool air coming out of the front vents at idle. That's with the OEM serpentine condenser.

Removing the old fan was easy enough. Remove the kidneys, break loose the three #8 bolts and disconnect the plug from the harness.

Once the old fan was out I tried several things to make the new fan fit and then realized that if I trimmed off one of the corners I could re-use the top mounting point. So that is what I did. I used the washers that held the original fan on and just drilled them a little bigger so that the new bolt would pass through. Notice how the bolt head perfectly fits into the fan mounting pockets and then clamps with the washer.

Image

With the top of the fan firmly mounted to the metal bracket, I felt comfortable using the plastic screws that come with the fan. I just pushed them through the openings of the condenser as instructed.

Image

This is what it looks like from the bottom.

Image

This is what you see behind the kidneys. Notice the corner I trimmed at the upper left, right next to the mounting bracket of the refrigerant lines.

Image

It will be over 100 degrees for the next two days, so I will really give it a good workout. So far, it is REALLY a marked improvement with in-town driving. I still have to figure out/fix where a PO might have spliced the harness and then create a jumper for the plug.

Jose
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Post by Da_Hose »

The new fan was working great!

However, I have discovered that the stock fan must operate WAY under the 30 amps the circuit is rated for. Even though the new fan only pulls 17 amps, it fried one of the wires at the fuse box. #-o

Inspection of the fuse box reveals that the connector on the wire that fried looks beat up. That tells me it is very likely that there was a corrosion problem creating a bad connection and a PO might have tried to fix it by bending the connector end to create a tighter contact. That would make the relay fit tighter, but actually could reduce total surface contact. The reduced contact points could then cause the wire to heat up and fry things. I have a Honda motorcycle with a known regulator problem due to the same kind of connector issue. The permanent fix on the Honda is to cut off the connectors and just solder wires. That is obviously not a good idea in the fuse box of our cars, so I will just replace the melted/burned section, put on a new connector and repair the K6 relay connection in the box. I imagine the relay is toast too.

Since only one side of the high power circuit melted, perhaps it can handle the constant 17A load when the wiring and connectors are healthy, but I won't take the chance. I will install a relay on the ground side of the fan and trigger it with the low speed circuit power lead. However, I will send 12V+ to the fan by piggybacking on the starter terminal where the battery power lead feeds it. I happen to have a spare 100A resettable breaker I can use at the firewall too. That will also let me have another good place to tap into power for the Fiamm/Euro sounding air horns I picked up.

Funny how one project just keeps feeding the next.

Jose
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Post by hornhospital »

Da_Hose wrote: Funny how one project just keeps feeding the next.

Jose
It's called 'mission creep', such as: you start out changing a headlight and end up rebuilding the entire front suspension "because you were there anyway". It never ends. :wink:
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BTDT, Ken . . .

Post by GRNSHRK »

A while back I was expecting to spend about 10 minutes cleaning my battery terminals, which lead to pulling the cables, which lead to removing the battery, which lead to the discovery that my battery tray was rusting out :roll:

About a month and a half later, my battery was relocated to the trunk and the trunk got a complete refinish, all new covering, everywhere =D>

Not to highjack this thread, but that "scope creep" issue is a big one [-X

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Post by Neveragain55 »

I don't know if your already using this product or if you've ever heard about it but I use it in all my cars including my 6, and the engine temps never get above where they're supposed to be.......even on the hottest days.
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Post by Da_Hose »

Heard good things about water wetter and just plain old water, but I have converted my M6 to waterless coolant.

I'm telling ya Bobbo. It's bad enough with a regular 6er, but the M just eats money in parts like I eat taco's at my favorite truck. That is to say ... voraciously.

Jose :lol:
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Post by Neveragain55 »

I first knew I wanted a 6 after watching the first episode of "Moonlighting" with Cybil Sheppard & Bruce Willis back in the day....(giving away my age here)

Of course back then I didn't have $50.000 dollars for a brand new BMW so I had to wait.

When I did all of my research before finally getting one a few years ago I really wanted an M6, but honestly after seeing 12 years of posts and having conversations with M6 owners I'm glad I didn't.

Don't get me wrong, I still love them to death, and I give you M6 cats a lot of credit for owning & maintain them.

But if all of us regular 6 owners have to love our cars to take care of them, I can only imagine what level of dedication you M6 cats must have.

Good luck with keeping her cool, I'm in California a lot on business so I know how hot it gets.
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Post by Da_Hose »

I fell in love with the M6, watching Lethal Weapon 2. At the beginning of the movie they were chasing a red M6 around the city. In most movies, they dub in the sounds of something other than the actual car being driven because they want a really "cool" exhaust sound. In Lethal Weapon 2, they used the sounds of the actual car being shown. The lines of the car and the exhaust note instantly turned the M6 into a dream car.

Now I have one and drive myself insane refusing to let anyone else work on it. [-X

Yeah .... owning an M6 is a special kind of crazy. \:D/

Jose
1987 M6 - My dream car
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