Fan control

Discussion pertaining to positive pressure E28s.
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Patrick McHugh
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Joined: Feb 12, 2006 12:00 PM
Location: Richmond, VA

Fan control

Post by Patrick McHugh »

I've removed my clutch fan and replaced it with a SPAL electric fan.

I've always had trouble with E28 radiator temp switches, they never seem to last.

Has anyone controlled a fan through megasquirt?

How about running a standalone fan controller? Something with a variable speed controller would be nifty.
T_C_D
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Post by T_C_D »

Talk to Moosehead.
ZenitramNaes
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Post by ZenitramNaes »

I'd be interested in reading about fan control through MS if you happen to find some info!
GI jonas
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Post by GI jonas »

Why not just use an auxiliary input for the ground to a relay and set the input to turn the fan on at a given temp.? Thats what I did and it works fine. No brainer. Variable speed would be more of a trick but I see no need for that.
RDAvena
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Location: Falcon, CO

Post by RDAvena »

I am controlling an electric fan through MS2Extra. I used the output for the fuel evap circuit to turn the relay on at a preset temp. It is under the spare ports in MS2extra:

http://www.msextra.com/doc/ms2extra/spareports.html
Shadow
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Post by Shadow »

I made alittle relay control circuit bottom left corner.

http://www.diyautotune.com/jwplayer_vir ... xample.jpg
Image


The temp switches on the side of the radiator are too high and they're just off-xxx*f on-xxx*f. They make it cycle like crazy. sux.
Jeremy
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Post by Jeremy »

PWM would be ideal. I don't know if Megasquirt supports a PWM output, but that'd be the way to do it if it's available. No relays or funny business. Power is a simple 12V lead and PWM signal controls speed.

There are good reasons all modern cars do it this way.
Nebraska_e28
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Post by Nebraska_e28 »

I'm running 2 fans currently. I configured one of the spare outputs to run a circuit on the proto area that switches a relay for the fans. I kicks on at the set temp that MS sees & then shuts them down once the threshold is met.

Image
mooseheadm5
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Post by mooseheadm5 »

I'm working on a PWM fan control. Currently it works on an analog input to control fan speed, which would be fine if I used a thermistor as a temp sensor, but for MS control I need to adapt it to the PWM output. Hope to have it ready soon.
civi
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Location: Canada

Re: Fan control

Post by civi »

@mooseheadm5: That is very nice that you are able to control the fan speed with PWN. I am curious how it works and want to learn about this controller .Could you post more information so that I will get the better idea about the working of the controller.
jodystevens
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Re:

Post by jodystevens »

Nebraska_e28 wrote:I'm running 2 fans currently. I configured one of the spare outputs to run a circuit on the proto area that switches a relay for the fans. I kicks on at the set temp that MS sees & then shuts them down once the threshold is met.

Image

This is one of the cleanest electric fan installs I have seen. This looks excellent. I think I will do something similar to this.
derrith
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Re: Fan control

Post by derrith »

I ran an e36 318i switch (80/88ºC) to control my spal and original aux fan on my M5. Did the same on my 535i.
Self Made
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Joined: Jan 24, 2015 11:44 AM
Location: East Coast

Re: Fan control

Post by Self Made »

derrith wrote:I ran an e36 318i switch (80/88ºC) to control my spal and original aux fan on my M5. Did the same on my 535i.
This is genius. Where can I find more info?
M. Holtmeier
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Location: Dallas, Texas

Re: Fan control

Post by M. Holtmeier »

Paul, put me on the list for one of those fan controllers. Gonna need one for the e28.


To answer the OP's question; Yes I controlled a fan through my ms2 with a relay circuit built into the proto area. The only issue I have with this is the electric fans will always be switching on/off at 100% DC. Very annoying. I ended putting the stock viscous unit back on. I want to go back to an electric fan because, well, you can't have an unsightly fan blade hanging out in a shaved engine bay.
marc79euro645
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Re: Fan control

Post by marc79euro645 »

I don't get why you would want to control fan through ecm. That's exactly what I hate about modern cars. Car overheats, replace ecm, alternator works ,but won't charge replace ecm. They've become so integrated it's stupid. I'll take a simple thermoswitch anyday.
just mho
marc
Xenocide
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Re:

Post by Xenocide »

mooseheadm5 wrote:I'm working on a PWM fan control. Currently it works on an analog input to control fan speed, which would be fine if I used a thermistor as a temp sensor, but for MS control I need to adapt it to the PWM output. Hope to have it ready soon.
Eh? If you're getting a PWM signal from MS you can just filter it to get an analog value as long as it's going into something fairly high impedance. I'm interested in the packaging and what this thing will look like. I laid out a PCB for a temperature controller using a PT-100 awhile back but haven't had the gumption to actually build one and cut some code. It sits in the corner with the other projects I'm neglecting :(

Wait another minute, if you're getting PWM out from MS why not just run it to ein big fuggin FET?
Cube
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Re: Fan control

Post by Cube »

Hello,

which SPAL fan have you installed (on the M30 I guess) ?
I am looking into replacing my visco with an electric one, but there is only about 5cm clearance between the waterpump and radiator and the 16" SPAL radiators are about 8.5cm thick... or are you simply shifting the fan aside a bit?

The double fan idea looks good, will they provide enough cfm?
M. Holtmeier
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Re: Fan control

Post by M. Holtmeier »

The dual fan setup I installed on my turbo car 7 years ago worked great. I used a couple of Summit fans like these:

http://m.summitracing.com/parts/sum-g4901

I ran it for 2 years or so. I just got sick of the abruptness of fans that ran at 0 or 100% DC.
Nebraska_e28
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Re: Fan control

Post by Nebraska_e28 »

My dual fan setup struggles a bit to keep up in extreme hot summers. I think I can attribute this to the extra heat induced into the radiator by my auto tranny. Might be time to go bigger.
Shadow
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Re: Fan control

Post by Shadow »

1 big single is the best.
unless you can't like space. :x
bhopp
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Re: Fan control

Post by bhopp »

Does anyone have any idea on the CFM one should run? I'm also planning on doing a electric fan conversion. I've found a couple of source online the consensus seems to be around 2000 CFM for a 6 cylinder engine.
As a general rule of thumb, follow these minimum cubic feet per minute (cfm) ratings when using an electric fan as the primary cooling source on a basic engine:

1,250 cfm for a 4-cylinder
2,000 cfm for a 6-cylinder
2,500 cfm for a 8-cylinder

http://www.onallcylinders.com/2012/08/1 ... asy-steps/
Rule of thumb. Only choose a mechanical fan over an electric fan if it's your farm tractor. An electric fan is preferred because when you need a fan the most (at idle or cruising speeds) an electric fan is delivering maximum air independent of engine RPM's. Fans that move 2000-2300 CFM's are worth the investment. Preference should be given to a "pull" vs. a "push" fan. Mounted on the engine side of the radiator, a pull fan does not interfere with air flow at highway speeds. All shrouded fans should be on the engine side of the radiator.
http://www.griffinrad.com/tips.cfm
delvin
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Location: Ft. Worth, Texas

Re: Fan control

Post by delvin »

Hola.

I have used one of these http://www.dccontrol.com/constant_tempe ... ollers.htm and various ford oem fans (V6 contour fans flow around 3400cfm) on supercharged v8's for long time with zero issues.
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