Outer Limits 4x4 Board

Putting a PWR water-2-air barrel cooler on the GU, and need to get a solution to switching the fan on the front mount radiator on/off.

Has anyone seen a temperature switch that would do the job, and at what temperatures should I be switching the fan on at?

- David.

75c to 90c

maybe 80c to 90c or could turn off later


Need to Know thread Pitch and size

There's a Jaycar kit that works well - I have one running the thermos in my sierra.

Steve.

beinthemud wrote:75c to 90c

maybe 80c to 90c or could turn off later


Need to Know thread Pitch and size

Those temps are near where you want the coolant water for the engine.

To get the best advantage from a water to air intercooler, I would like the water temp to be much lower than 80C.

yeah sorry miss re what was being asked
We Do tridon temp sender

there is a thread in the auto elec section (by Chimboy) that has a list and pics of temp switches, worth checking it out

Edit: its a sticky at top of the page

Cheers,

From Chimpboy's post, there are senders available (TFS 155 & TFS 159) that have a 50oC on and 45oC off which is going to be closer to the mark. Would be better for a 10oC (ish) drop but will do for now.

Pitty they switch to earth, will have to sort something out.

- David.

G/day David
We went away from temperature switches right near the start of our development programme 8 years ago, effected by ambient temperature too much. On a 25c day, I can't see that you will ever see water temps over 38c out of the cooler - if it's sized right - & that's with 120c charge air out of the turbo. Best is a Hobbs boost switch. if you're running 12 psi boost, buy an 8 psi switch (contacts normally open version- important- & wire in a relay so the switch will last for yonks.
Regards Richard

Boost switch sounds like a better idea. Looking at 15psi, so the 10psi should do the trick.

Where are the normal places to get a "Hobbs" switch? Only limited places have popped up with a Google search?

- David.

How often during a drive does the car cross the 10psi mark. ie are you going to be having the fans switching on and off all the time??

I can see the benefits of using a hobbs switch for water injection or spray where the actuator is more suited to going on and off all the time but you might find the fans have issues after a while if they are switching on and off frequently while your driving.

I always though fans were supposed to be used at low speeds where the airflow over the raqdiator is not enough to cool the water which cools the intake charge. ie run off the fans of a speed sensor. Often at high speeds the fans can slow the air flow through the radiator (this is provided the radiator is setup right place).

Also the effect of fans switching on and cooling the intake charge will be slow (how slow depends on the volume of water in the system and efficiency of the radiator), as the fans have to first drop the water temp which will then drop the air temp. So by the time the fans have switched on and cooled the intake charge you may be off boost again loosing all the benefits of the now cooler incoming air temps. This is as opposed to water injection directly into the manifold or a spray over an air-air intercooler which will have a very rapid cooling effect due to evaporation.

My personal choice would be to try and keep the water temp as low as possible always having the coolest intake charge possible.

I really cant see the hobbs switch being effective unless you are on boost for long periods of time. When you are off boost and intake temps are lower is when you will be able to cool the water temp the most for when the motor is next on boost again and pumping heat back into the system. Its like trying to make the fans work hard all the time when they're on instead of letting them catch up when the incoming air intakes are lower (meaning less heat is entering the system at this point in time).

Sorry if this is shuffling about a bit as I'm tired and had a few beers now But I'd like to see more of an argument for using a hobbs switch in this particular instance.

Stuee,

I am currently running 11psi, and other than cruzing around at 60km/h boost is 10-11psi.

The issue I cannot solve without introducing computers is that just running around, even slowly at 10psi or less, no intercooler is fine, but when running hard in sand, or in steep slow areas where I am running full boost I need the fan to kick in and help keep a lid on all of the engine temperatures.

So which way to go. The water temp switches are really to high to be of much use? (though switching on at 50oC is going to be the ticket when temperatures are running out of control) And with the pressure switch the fan is going to be on most of the time anyway?

Almost thinking that a switch on the dash is going to be the most reliable option?

More opinions please......

- David.

go and grab yourself a frequency switch from jaycar, piggy back it in to your speedo signal from transfer case and switch via road speed. this switch is adjustable so it can turn on at say 0kph off say at 35kph and the as you slow down turn back on at 10kph. all these speed activated triggers are adjustable

GunGU

G/day Stuee
I'm the dozzie one. We use the hobbs switch too control the water pump, as we use an 80 lpm. Davies Craig pump which is overkill for normal driving. We have a box which runs it at 5.5v until comes onto set boost & then switches too full battery voltage & then stays on this for an extra 25 secs after it drops below set boost, to get rid of heat soak in the system.
The Hobbs switch seems a better way than a higher temp switch but gungu's speed related switch is probably the best of all.
For on road use, I don't beleive a fan is needed at all.
www.are.com.au/Inter/Graphs/HiLux aw03-02 8-38.jpg
Sorry, I can't make the link work, please type it in manually - with spaces
This is a data log of a return drive over a short hill (3/4k.)at the back of work. The ambient temp is 24c. Charge air temp out of turbo is around 107c., after intercooler 38c., water into cooler 26c., water out of cooler 28c. Total log time is only a couple minutes, so the heat rise & fall are almost instantious in relation too throttle application.
This is why I was suggesting to get away from a water temp switch, but really, a speed switch is the way to go for a fan, pressure for pump.
Sorry about the long post, but I feel it's important to know what sort of temps your dealing with, because air/water is heaps harder too set up properly compared to air/air.
Regards Richard[/url]

If there was a consensus that the intercooler is not really needed on road and more so the fan assistance is not really needed on road then how about a trigger from the 4wd activation so it activates when the transfer is shifted to 4wd. Maybe no good on older trucks but would certainly work on anything with electrical input on 4wd selection like 80 series and in this case the auto locking hubs of the GU.

I like the speed triggering myself also but just offer this as a more basic and cheaper alternative.

Really it has to be temperature controlled, I mean an intercooler is there to remove excessive heat caused from boost. therefore a temp sensor seems to be the best answer, I don't think a boost switch is the best set up, as it would be forever turning on and off.
to say you only need to run it when in 4WD doesn't ring true, I think you need the intercooler to work at all times when excessive heat is produced, this would be and highway speeds, towing, going up hills, slow speed 4WDing, what ever. I don't think the air flow from road speed would be enough to cool the intercooler radiator sufficiently. (and if it was then a temp switch would not turn the fan on, so no loss)
A water to air intercooler will have some ability to soak up heat for a short period before the coolant temp went above a desired temp,
I wounder if you could set up a temp switch that was ambient sensitive, set at say 10 above ambient
I am looking at using a electronic guage with a built in temp switch ( adjustable in cab on the fly) the same ones used in the EGT group buy, the web site listed a water sensor available soon, and that was about a year ago when I brought mine,
I am also long for a better water pump set up if anybody has any ideas.

Good post Greypower, I really should read all posts before replying, sorry.
I think I need to do more research, cheers.

Where I am at is that a fan isn't really needed anyway on a street going vehicle, as when ever I am going to be on boost the vehicle will be moving and thus at least some air flowing. So the fan will just be there to try an put a lid on temperatures that are climbing out of control for whatever reason.

So my decision is to mount a temperature switch on the outlet of the front radiator to control temps. Will us a 50oC on and 45oC off, which are standard on 22R Hilux's and 2F Landcruiser's.

Anyone have some 22R Hilux or 2F Landcruiser parts lying around they can supply me with the fan switch from? New price on this switch is a bit rich and I also need the plug from the wiring loom.

- David.

Dirty wrote:Where I am at is that a fan isn't really needed anyway on a street going vehicle, as when ever I am going to be on boost the vehicle will be moving and thus at least some air flowing. So the fan will just be there to try an put a lid on temperatures that are climbing out of control for whatever reason.

So my decision is to mount a temperature switch on the outlet of the front radiator to control temps. Will us a 50oC on and 45oC off, which are standard on 22R Hilux's and 2F Landcruiser's.

Anyone have some 22R Hilux or 2F Landcruiser parts lying around they can supply me with the fan switch from? New price on this switch is a bit rich and I also need the plug from the wiring loom.

- David.

Well If going by ARE's chart then its likely that your fan will not turn on for a fair while, if at all, and by the time it does, you may have lost a lot of the coolers efficiency anyway.

If the fans not really needed, it begs the question of why bother??

fester2au wrote:If there was a consensus that the intercooler is not really needed on road and more so the fan assistance is not really needed on road then how about a trigger from the 4wd activation so it activates when the transfer is shifted to 4wd. Maybe no good on older trucks but would certainly work on anything with electrical input on 4wd selection like 80 series and in this case the auto locking hubs of the GU.

Nearly every 4x4 i've been in has a "4x4" light or trans-lock light, so this could be used as a switch - however as said its not really a good choice.

What about an air temp probe/sensor on the turbo compressor outlet or pre-intercooler?

A fan cooling the radiator will not have the same cooling dynamics as stepping the speed of the pump as in GreyPower's case. So switching the fan on in response to spikes in inlet temp or the water temp at the exit of the cooler will not have the desired result of cooling as explained by GreyPower. Think about how long it takes your engine temp to move a significant amount when the thermos come on.

If anything the fan is only there to make up for low speed operation which has already been pointed out. The speed sensor or low range indicator would be the best bet for switching the thermo fan on the intercooler radiator. Low range would be most simple as there's most likely wiring already there as pointed out by coxy321, and its likely you wont be traveling at any sort of speed when in low range which is the sort of situation you want your fans to be on, if they are even required at all.

Depending on where the intercoolers radiator is placed, you may even get air flow being pulled through by the engine fan.

coxy321 wrote:

fester2au wrote:If there was a consensus that the intercooler is not really needed on road and more so the fan assistance is not really needed on road then how about a trigger from the 4wd activation so it activates when the transfer is shifted to 4wd. Maybe no good on older trucks but would certainly work on anything with electrical input on 4wd selection like 80 series and in this case the auto locking hubs of the GU.

Nearly every 4x4 i've been in has a "4x4" light or trans-lock light, so this could be used as a switch - however as said its not really a good choice.

What about an air temp probe/sensor on the turbo compressor outlet or pre-intercooler?

That too would be my choice in a perfect set up coxy. I think sensing and cooling the water is the round about way of doing it but in reality the easiest to do. However assuming the set up is sized and built to an ideal format I think that sensing and triggering off a preferred/predetermined air temp would be the best way to go. Triggering the set up of water is a bit cart before the horse. However to run the system off air temp although just as easy would really need a good bit of data logging to see what the system is actually doing and capable of. Then the format is the same use a temp trigger to turn on and off within a preset air temp range.

Those Auber Instruments EGT gauages for example that many of us got from a group buy here could easily perform this function (water triggered for that matter too) they can be conffigured to sense off alomost any sensor as long as you know the voltage range/scale and they have a triggering output tha can be adjusted.

Andy at DieselTec is quite involved in the Laminova W/A intercooler project. I know that they have done quite a bit of R&D on these, which has also included a lot of data logging for air and water temps. Although a PWR/Denco/FrozenBoost setup is almost a completely seperate kettle of fish, i would assume that there would be some amount of data that could be used as a reference point for the "cheaper" W/A systems.

Ok,

Going to run it off the 4WD switch. Should be able to pick it up under the dash as it switches to earth.

I think switching of air or water temperature would be fine, if you could get a switch at a low enough temperature on the basis that if you are under boost you are going to be moving and there will be at least some air flowing though the cooler.

The temperature based switching will bring the fan in when the temps start to rise outside a normal operating temperature and not in for normal operation.

- David.

Had a fan hooked up to an intercooler on a car and the easiest way was to just have a switch on the dash.

Having it come on just with boost does not work well as it is never on long enough and u get a heap if heat soak.

When i was cruizing around town there was enough air flow so the fan was not needed. In heavy traffic or in your case slow 4wdriving the fans should just stay on. It can never be too cold!!