Best electric cooling fan improvement for a 6er

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Da_Hose
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Post by Da_Hose »

This should be the final update for the fan upgrade project.

Since the factory wiring can't handle the constant 17A load of the new fan, I put in a new circuit. It connects to the starter terminal wired directly to the battery and feeds a 100A marine grade, resettable breaker.

Image


Then it feeds a Derale relay with a 25A constant load rating and 60A peak.

Image

From there, the power feeds to the fan and the fan is grounded to the nose. The trigger lead is fed by the power 12V+ lead that feeds the temp. sensor.

Now the accessory fan feeds directly from the battery with a 10ga. wire and turns on as soon as the key is in "Run" position.

Jose
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Neveragain55
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Post by Neveragain55 »

Wow.....

Did you do all that wiring yourself, that's really impressive.

I'm really good with cars all the way around but I'm not good with electrics beyond the simple stuff.
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Post by Da_Hose »

Yes, I did it all myself. Thanks for the props on the work. 8) Electrical can definitely become a nightmare. Thank goodness we have that ETM in the tech. docs. section. It's a great resource for tracking down wiring issues.

I also did a battery bracket fabrication and re-wire project recently.

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Post by Neveragain55 »

Nice................
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Re: Best electric cooling fan improvement for a 6er

Post by ronnieg »

Does anyone have a spec -- or a guess -- for how many cfm the stock 6er cooling fan pushes? am trying to decide how many cfm to upgrade to. am in TX, and have black interior. all windows are tinted, but when it gets over 100......
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Re: Best electric cooling fan improvement for a 6er

Post by ronnieg »

Just installed a Syclone 15" fan that I got on ebay for $98. Added a 30a relay to supply the power directly from the battery. Followed the directions that DaHose posted earlier, so mounting it was pretty easy. Took about half the time get the hood back on and aligned properly. Thanks to DaHose, and others who posted.

Now I need a good hot day, and I'll report the results.
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Re: Best electric cooling fan improvement for a 6er

Post by ronnieg »

here to report that the new Syclone fan is working well so far.....has only been in the 90's for a high, but I think I can already tell it is better than the stock fan.
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Re: Best electric cooling fan improvement for a 6er

Post by Brucey »

ronnieg wrote:Does anyone have a spec -- or a guess -- for how many cfm the stock 6er cooling fan pushes? am trying to decide how many cfm to upgrade to. am in TX, and have black interior. all windows are tinted, but when it gets over 100......
there are two stock 6er fans; the Bosch one and there is a later style of fan that looks a lot more efficient (and has a curved blade design etc) runs more quietly etc but isn't reliable, not anywhere it is damp and freezes, anyway; I've broken about three of the later type of fan.

FWIW I think the Bosch one will have a lower CFM value, but the other one is likely to be comparable with other fans of similar size and motor power. Both fan types draw about 10-12A when they are running at full speed, but can (briefly) draw a lot more than this on start-up, which is why the circuit is fused for 30A.

BTW if there is much in the way of a gap between the AC condenser and the radiator, a pusher fan at the front will tend not to push air through the radiator very well; it may well leak out sideways in the gap.

I have wondered if fitting a fan between the radiator and the condenser would work best of all, but it would be a lot of work to move the condenser a couple of inches forwards.

cheers
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Re: Best electric cooling fan improvement for a 6er

Post by ronnieg »

Thanks, Brucey. the Syclone fan sits directly on the condenser, so I think it will work fine. so far, so good....
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Re: Best electric cooling fan improvement for a 6er

Post by redrumm3 »

I have been running a Spal Fan on my E36 M3 race car without a mechanical fan for quite some time without any issues. They are available in 7.5"-14" diameter with either a push or pull configuration. They can be wired to the factory relay or an external one. I have been very happy with it in race conditions here in Florida and the Southeast where we have some extreme summer temperatures. Never any overheating issues with it.

http://www.bimmerworld.com/Cooling/Fans/

I also use Water Wetter. Its seems to help, but I cannot confirm it's effectiveness. Be sure to use it in conjunction with a normal coolant since it does not have any corrosion inhibitors.
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Re: Best electric cooling fan improvement for a 6er

Post by slofut »

redrumm3 wrote:I have been running a Spal Fan on my E36 M3 race car without a mechanical fan for quite some time without any issues. They are available in 7.5"-14" diameter with either a push or pull configuration. They can be wired to the factory relay or an external one. I have been very happy with it in race conditions here in Florida and the Southeast where we have some extreme summer temperatures. Never any overheating issues with it.

http://www.bimmerworld.com/Cooling/Fans/

I also use Water Wetter. Its seems to help, but I cannot confirm it's effectiveness. Be sure to use it in conjunction with a normal coolant since it does not have any corrosion inhibitors.
I think the more extreme issue is when sitting still on I-75 in a sea of cars for an hour (or more) in the middle of summer!
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Re: Best electric cooling fan improvement for a 6er

Post by jps635 »

I've had my set up (detailed earlier above) running for about 15 months now and am now fully confident in it so have stopped carrying the clutch fan and 32mm spanner around. Good things are with this set up is the thermatic switch is infinitely adjustable, so can tune to your environment, the tell tale light shows when it is running and it can be over-ridden. Did a lot of stop start driving a couple weeks ago and no issues.
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Re: Best electric cooling fan improvement for a 6er

Post by redrumm3 »

slofut wrote:
redrumm3 wrote:I have been running a Spal Fan on my E36 M3 race car without a mechanical fan for quite some time without any issues. They are available in 7.5"-14" diameter with either a push or pull configuration. They can be wired to the factory relay or an external one. I have been very happy with it in race conditions here in Florida and the Southeast where we have some extreme summer temperatures. Never any overheating issues with it.

http://www.bimmerworld.com/Cooling/Fans/

I also use Water Wetter. Its seems to help, but I cannot confirm it's effectiveness. Be sure to use it in conjunction with a normal coolant since it does not have any corrosion inhibitors.
I think the more extreme issue is when sitting still on I-75 in a sea of cars for an hour (or more) in the middle of summer!
On more than one occasion I have been still in the car idling for as much as 20 minutes during a red flag and the car has not overheated. I sat there idling because I didn't want the motor to heat soak.
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Re: Best electric cooling fan improvement for a 6er

Post by Brucey »

it is worth noting that there will be a difference not only with ambient temperature, but also with car specification.

A car with a manual gearbox, no AC, at idle, will be chucking out maybe 1-2 kW of heat. This is about the same as a domestic hairdrier, not much. Even a pretty knackered viscous fan will usually pull enough air to manage this OK. [ If it doesn't, you can 'help out' by turning the heater on inside the car; better that you cook than the head gasket fails....?... :roll: ]

At full throttle the radiator on the same car might be chucking out about 100kW or more, but when the car is moving, there is loads of airflow, so the cooling system can cope quite well. Obviously if you are driving flat out and coming to a sudden halt then (briefly) the cooling system has to reject the most recently generated heat even though there is no airflow, only that provided by the fan. So if the cooling system can deal with 5-10kW of heat then the engine may heat soak a little for a few minutes after a hard run/stop. This is when a really powerful fan can help.

However if you have an autobox car with AC, then suddenly you have an extra load on the engine and it's cooling system. The autobox rejects heat into the radiator via the oil cooler. Even in neutral gear after a run there will be about 0.5kW of heat for about ten minutes this way, before the gearbox oil cools to the same temperature as the radiator. If you leave the car in gear, in traffic there will be another 0.5kW or so of heat to contend with, all the time. A decent AC system is a 0.5 to 1kW (or more) 'fridge' and there is a double whammy here; every 0.5kW of heat in the gearbox oil or AC system can only be generated by creating an additional 0.5kW of heat in the engine, and it all ends up being rejected in the vicinity of the radiator. So the heat rejection of an autobox car with AC, in traffic, might well be 4-5kW or so; in any event it is a lot more than a manual gearbox car with no AC.

Note also that running the electrical system also loads up the engine (another 0.5kW of engine heat perhaps if you have the lights on and are running a powerful stereo) and so does using the brakes and the PAS; another 0.5kW of engine heat is likely whenever the PAS pump is working hard.

Many of these things might not seem like they ought to make much difference, but they all add up.

cheers
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Re: Best electric cooling fan improvement for a 6er

Post by ronnieg »

A quick update..... the Syclone aux cooling fan is doing a great job, even better than expected. it's gotten to 100 degrees in Texas, and the A/C blows colder than ever, and the compressor has never turned off due to the thermal cutoff. the temp gauge stays steady as well.

best $100 I ever spent....
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Re: Best electric cooling fan improvement for a 6er

Post by sansouci »

Jose,
Can you repost the pictures regarding this thread as I'm doing an a/c refresh with a new fan? Photobucket seems to have screwed everyone.
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Re: Best electric cooling fan improvement for a 6er

Post by Hakeem43020 »

sansouci wrote:Jose,
Can you repost the pictures regarding this thread as I'm doing an a/c refresh with a new fan? Photobucket seems to have screwed everyone.
You can use the SPAL 30100401 16 inch pusher fan. 16 inch is the biggest that can fit(assuming you use a 16x19 condenser).
I used it along with a parallel flow condenser and have had no issues. Make sure you get the "pusher" fan and not a "puller" though.
I uploaded a picture and the process here: https://www.bimmerforums.com/forum/show ... st29740919
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Re: Best electric cooling fan improvement for a 6er

Post by ron »

Hakeem43020 wrote: You can use the SPAL 30100401 16 inch pusher fan. 16 inch is the biggest that can fit(assuming you use a 16x19 condenser).
I used it along with a parallel flow condenser and have had no issues. Make sure you get the "pusher" fan and not a "puller" though.
I uploaded a picture and the process here: https://www.bimmerforums.com/forum/show ... st29740919
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Re: Best electric cooling fan improvement for a 6er

Post by Hakeem43020 »

ron wrote:
Hakeem43020 wrote: You can use the SPAL 30100401 16 inch pusher fan. 16 inch is the biggest that can fit(assuming you use a 16x19 condenser).
I used it along with a parallel flow condenser and have had no issues. Make sure you get the "pusher" fan and not a "puller" though.
I uploaded a picture and the process here: https://www.bimmerforums.com/forum/show ... st29740919
Put your location in your profile as requested by admin.
Sorry, must've missed that one. Just added :)
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Re: Best electric cooling fan improvement for a 6er

Post by pgh880 »

Hi ,

Our weather in our country the Philippines is hot and humid , maybe worst than your weather in SoCal . I replaced my OEM electric cooling fan w/ the one's use by Mercedes Benz models W124 & 126 . Its slim powerful its 16 inces in diameter and it really help the engine cool w/ the AC on in bumper to bumper traffic .Make sure to get the Bosch brand . But its loud and howling sound is the only drawback .

Hope this helps ,

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