R32 Gtr Engine Fan Temperatures

[Bozz]

and tell me, what is the main contributing factor of air temps in the engine bay? the coolant temp. if the coolant temp is sky high, even on a cool day the engine bay temps are going to he higher since a majority of the air coming into the engine bay is being drawn through the radiator. also since the fan attatches onto the front of the water pump, which is going to absorb heat from the coolant and thus the viscous coupling is also going to absorb some of the heat from the water pump, once again the coolant temp is indirectly affecting the workings off the fan. also any heat radiating off the engine will also be directly related to the coolant temp. the lower the coolant temp the lower the temp of the engine block and the lower the temp of the air in the engine bay.

unlike you the OP doesn't appear to have actually checked (or at least hasn't posted up about it) to see what his water temps are when his fan is roaring. in your case, your viscous coupling is obviously stuff and staying locked up, but in the case of the OP, his car may possibly have a cooling system issue that is cause the car to nearly boil, but he isn't bothering to look into that, he just wants people to post up the ambient temp that their fans are coming in at, which is a pointless exercise as every car will be different as not everyone's cooling system will be work at the same effeciency as others. if someones radiator is 15% blocked then their fan will kick in at a lower them than someone with a brand new radiator. so the OP should be looking at what temp his engine is actually running at as that will immediately tell him whether his fan is working properly or not and he could've had his problem solved 2 months ago.

another one

Water pump shaft: steel

Thermal conductivity of steel: approx 20-40 (low) (aluminium is over 200, copper over 300)

Approx contact area of metal-metal coupling where viscous clutch couples to water pump shaft via 4x 10mm nuts: Very small. For reference, a well machined surface like a computers CPU heatsink makes around 2-10% contact. Thats why heatsink compounds are needed.

So, I guess you're right. It does transfer some of the heat from the coolant via the water pump shaft. Perhaps under 1% of it.

[mad082]

oops

i looked at your full post there, and what pipe are you measuring the temp off? cause if your water temp is getting as low as 30 degrees when driving then you are obviously measuring the water coming out of the radiator and not what is coming out of the head. or your gauge is totally stuffed. or was the 30 and 45 degrees the temp of the water coming out of the head and the car is still running up to around 80 degrees.

also i wasn't saying that if the fan isn't working properly that the engine could overheat, but i was saying that the fan may possibly be working properly but you may actually have an overheating problem in the engine which you are ignoring.

another one

Water pump shaft: steel

Thermal conductivity of steel: approx 20-40 (low) (aluminium is over 200, copper over 300)

Approx contact area of metal-metal coupling where viscous clutch couples to water pump shaft via 4x 10mm nuts: Very small. For reference, a well machined surface like a computers CPU heatsink makes around 2-10% contact. Thats why heatsink compounds are needed.

So, I guess you're right. It does transfer some of the heat from the coolant via the water pump shaft. Perhaps under 1% of it.

next time you have the car running you grab a hold of something steel in the engine bay and find out just how hot it can get. also correct me if i'm wrong, but the viscous coupling is touching more than just 4 nuts. now coorect me if i'm wrong, but it actually sits on an alloy pulley, and as you just said, alloy conducts heat very well.

[NSNPWR]

Was forced to refit my fan today...sigh....the hoovers back.....................

[Bozz]

Was forced to refit my fan today...sigh....the hoovers back.....................

It saps the engine of otherwise useful kilowatts

I found a Subaru RX twin thermofan is the right dimensions. Need to find out if the same year WRX has a more powerful fan within the same dimensions although its significantly less powerful than the Ford Falcon fans. Will measure return water temps when I could be arsed to fit it.

I'll also design a circuit to keep the fan running a few minutes after shutting down the motor to help cool it further. Will post more info when I get motivated enough to do it.

Cheers

[NSNPWR]

The AU-El def dont fit, theyre too wide and too tall...not much room at the front there with them power steering lines running so close...I found some fans on Ebay that will fit, think theyre 2 10s but unsure of brand....and therefore reliability or cooling powerzzzzzzz.....

[wht510]

Just to add my 2 cents.

In my car (datsun 1600 with an SR20DET and a 12" thermo fan with a BMW 7 series radiator), the thermo fan is set to trigger when the water temperature is 92deg C. I don't run an viscous clutch engine fan.

The temperature probe for the ECU is in the engine block.

You would be primarily interested in the coolant temperature. Like previously said, when a car is driving either under full throttle or partial, the only thing the fan/thermostat or ECU is interested in for keeping the car cool is the coolant temperature.

IMHO, the viscous fan uses the water temperature (by the time the thermostat opens) to maintain the temperature. Supposedly this should be around 80 something (depending on the clutch) where full engagement is.

I would check the following:

What temperature the thermostat is opening? It sounds like yours is open all the time, which I think it shouldn't be. This might explain why the fan is on all the time.

Have you replaced the viscous centre with another?

Don't replace the mechanical fan with thermos yet until you have found out whether another problem is causing things to get hot or open the thermostat.

On my RB20DET'd HR31, the old viscous fan used to lock up and sound like a leaf blower. I replaced the viscous fan with a newer one, and it was fine. In my case it was the viscous centre.

[Bozz]

wht510 - have I seen you at Dr Drift? I think I've seen your setup and it looks great.

I was thinking of going nuts with cooling control - twin thermofans can easily be wired up to work in two speeds (series and parallel) so if I could throw a few inputs through an ADC then into a microcontroller with enough inputs/outputs (eg atmega168) then I could easily and cheaply make it do some good things with cooling by monitoring existing sensors to make the fans work when needed and switch off when not needed.

Thoughts on inputs using existing sensors:

- Speed (switch fans off over say 50km/h)

- Ambient temp (reduce thresholds to switch fans on as temp increases)

- Coolant temp

- Return coolant temp (if too high, run fans on high, if too low, throw a warning light - most likely out of coolant)

- AC

- Ignition (when ignition turned off, fans run for a few mins to reduce heat soak based on how long engine has been on and ambient temp)

Outputs:

- Fan on/off

- Fan speed low/high

Anyone ever done something like this?

[mad082]

wow, that is going to town with the cooling control. the staying on for a few mins after you turn the car off isn't a bad idea, as long as it doesn't malfunction and run for hours and flattern the battery.

i know that in my pulsar there are a few different factory settings. i will take a screenshot of the workshop manual at work tomoro because i can't remember what they are, but i know there is speed dependant settings and aircon dependant settings.

2 other cars with factory thermos you could measure up would be V6 magna or GTiR pulsar fans.

[wht510]

Yup you have seen me at Dr Drift. I do own a white Datsun 1600

The only problem I see with your setup is the complexity. For something that needs to be ultra reliable in cooling the car, you don't want to make the cooling too complex. Unless you are buying something or you are an electronics wizz, then go for it...

There is a MoTeC PDM I think it's called which could possibly do all of this and more. I recommend if you are going to do all of this, go for a brand name system and do it!

wht510 - have I seen you at Dr Drift? I think I've seen your setup and it looks great.

I was thinking of going nuts with cooling control - twin thermofans can easily be wired up to work in two speeds (series and parallel) so if I could throw a few inputs through an ADC then into a microcontroller with enough inputs/outputs (eg atmega168) then I could easily and cheaply make it do some good things with cooling by monitoring existing sensors to make the fans work when needed and switch off when not needed.

Thoughts on inputs using existing sensors:

- Speed (switch fans off over say 50km/h)

- Ambient temp (reduce thresholds to switch fans on as temp increases)

- Coolant temp

- Return coolant temp (if too high, run fans on high, if too low, throw a warning light - most likely out of coolant)

- AC

- Ignition (when ignition turned off, fans run for a few mins to reduce heat soak based on how long engine has been on and ambient temp)

Outputs:

- Fan on/off

- Fan speed low/high

Anyone ever done something like this?

[Bozz]

Yup you have seen me at Dr Drift. I do own a white Datsun 1600

The only problem I see with your setup is the complexity. For something that needs to be ultra reliable in cooling the car, you don't want to make the cooling too complex. Unless you are buying something or you are an electronics wizz, then go for it...

There is a MoTeC PDM I think it's called which could possibly do all of this and more. I recommend if you are going to do all of this, go for a brand name system and do it!

Its something I want to do - i've been wanting to learn modern microcontroller programming for a while and now I've got a need so I'll get my arse into gear and get it done in the next few months. It'd be a good idea to have an override just for engine temp, if the temp is too high, it just switches on a relay - not running through a microcontroller or anything, just a simple analog circuit.

$30 worth of parts and wire is all you'd need. The only thing I could possibly screw up is the code, I only see a bit over a dozen parts would be needed:

5V voltage reg

The atmel microcontroller (I googled it and it has a built in ADC so life would be stupidly easy)

SIP capacitor array (uC input spike protection)

half a dozen resistors for input decoupling and voltage matching (from memory the atmega48/88/168 series use 5v - need to research if there are any 12v uC's available that aren't too difficult to program)

three relays for the fans (one SPST for on/off, two DPDT to provide low/high speed)

a couple of transistors to drive the relays

I'll post how i go. Going to research if i need to buy the Atmel programming kit (probably will because they're so common) or if something else like PIC or whatever will work better. I'm still pretty new to it all.

[nismo32gtr]

I am actually looking into engine temps myself for my gtr , im going to put air con into it (as i bought it without it) and am really unsure what to do fan wise i will be running a pwr 43mm radiator , would it be best just to keep the engine fan and get the air con fan wired so it switches on when the aircon does or would a single or twin thermo keep it cooler instead of the engine fan. i am wanting something that will be reliable and keep temps down?

[NSNPWR]

Something like this would fit quite comfortably -

http://cgi.ebay.com.au/TWIN-THERMO-FAN-10-...=item48397a1e38

But doesnt say anything about cfm or anything like that...

nismo32gtr, my air con fan is wired to a switch...didnt know it was there when I first got the car and was wondering why the air con sucked ass in traffic!

[mad082]

this is the parameters that are used by the factory ecu in the pulsars

[grigor]

I was thinking of going nuts with cooling control - twin thermofans can easily be wired up to work in two speeds (series and parallel) so if I could throw a few inputs through an ADC

Anyone ever done something like this?

Yes.

Anyone with a re-powered S13 has to go this route and it's a root.

My Rb20/S13 Rustia had 2-12" thermos (pulling) and the factory R32 aircon fan in the front (pushing)

The twin thermos were wired series/parallel with low heat switching from a sensor in with the coilpacks and high heat switching from the R32 radiator bottom tank.(standard Tridon switch)

Activating the aircon switched on the R32 pusher.

The twins also were on an adjustable timer for cool down.

The cool down timer killed the tiny S13 battery in nothing flat, so it was removed.

The alternator couldn't keep up with the huge draw, especially at night in the rain, so the R32 pusher was disconnected.

Car ran so cold, the fans never ran on high speed anyway.

BUT what a mess.

The factory engine driven fan is by far the best way, just isn't an option in the limited space.

[Marko R1]

my tuner (crd) recommends leaving the clutch fan as he said that thermo fans will not cool as effective as the clutch fan - food for thought...

[NSNPWR]

So can the other 32 GTR OWNERS comment on whether their clutch fan is noisy?

I will explain mine again....

*Start car, idling, no fan noise.

*Bring revs up to 2000 or more and hold revs there, CAR IS COLD, bonnet is open - fan sounds like a hair dryir on steroids and does not disengage like other cars ive heard regardless of revs

I actually put the hub assembly in the oven the other day and it was easier to spin when hot, shouldnt it be easy to spin when cold as when its cold isnt that when it should be disengaged???

Edited February 25, 2010 by NSNPWR

[Marko R1]

So can the other 32 GTR OWNERS comment on whether their clutch fan is noisy?

I will explain mine again....

*Start car, idling, no fan noise.

*Bring revs up to 2000 or more and hold revs there, CAR IS COLD, bonnet is open - fan sounds like a hair dryir on steroids and does not disengage like other cars ive heard regardless of revs

I actually put the hub assembly in the oven the other day and it was easier to spin when hot, shouldnt it be easy to spin when cold as when its cold isnt that when it should be disengaged???

i am an r32gtr owner & can comment on my fan, sorry i should have added this to my original post - it always sounds noisy even on cold start up, like a spitfire plane!

ive never heard my engine without the sound of that gay fan BUT it is the best for cooling!

[NSNPWR]

Take it off and go for a drive mate, you will feel how much more freely the motor revs and less throttle required to make it move...

[Marko R1]

u think so? hmmm, maybe i should try it

[NSNPWR]

Trust me mate, its not right, mine didnt get hot when I drove it with no fan, was only a 20 minute drive...got up to 84 degrees by the time I got home.

Do some reading, yours sounds identical to mine and it will be robbing HP and killing Fuel Consumption...its locked on, so its like driving with the air con all the time but worse.

Ordered a 16" electric fan for mine, 3000cfm, going to incorporate it into the factory shroud, seal it off around the edges...see how it goes....

Edited February 26, 2010 by NSNPWR