Were to set my fans to come on at

1-2clutch-u

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Feb 18, 2006
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As the race season is almost here I'm trying to get the last min bugs worked out. I have a 7mgte, 160 t stat 3 row rad and 2 12in fans with shroud. I have a fan controller and I would like to know were I should set it to come on at and what my race temp should be? Thank you
 

1-2clutch-u

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not at all but this is the set up I have, A lot of people say fan clutch it may be better for some peole but mine went wayyy hot and yes it was working right at the time.
 

IJ.

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Mar 30, 2005
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I found with e-fans in a Mk3 you need to get them on 10>20 under where you want the car to run as if you leave it till it's at the temp you want it overshoots and if the load is heavy it can never catch up, pulling em in early gives the system a head start then it's fine!
 

IJ.

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You'll find the combination has a natural equilibrium point, my car was 91c/195f and that's where it maxxed out under boost once everything was "right" this of course would vary with ambient temps but not as much as you'd expect, from memory I was running an 88c T Stat and was bringing the fans on around the 89c mark.

I think the 190 suggestion was the stock ECU is expecting that as it's normal operating temp, if you force the car to run cooler timing/fuelling changes.
 

figgie

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Mar 30, 2005
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IJ.;1813781 said:
...I think the 190 suggestion was the stock ECU is expecting that as it's normal operating temp, if you force the car to run cooler timing/fuelling changes.

What IJ. is alluding to is that at 160, the car will oerate in open loop and not get into the closed loop portion of the EFI and ignition maps.

It is one of those things best left answered by 3P and his rev-engineering project.
 

jt2ma71

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Mar 30, 2005
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I set my fans to come on at 180F and off at 178F. When cruising, temps would drop down to below 178F. At Idle, it rises, fans come on, temps go up to about 182-183 and start to drop down again so fans just shut on and off. This was all after the switch to TRD thermostat.

side topic, I will be installing a race grade dual output solid state relay to control the fan speeds depending on temp and road speeds. Good idea or not?
 

figgie

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Ron

you are going to do PWM on it right?

If so, that is the best option as the solid-state relays can be fed a high Freq signal to control the speed (no higher than 240 hz) . :) In your case from the ADL as that has a PWM output. Just create a 2d table.

Temp/MPH with the Cell = PWM % in the ADL software :)
 

A. Jay

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Like IJ said, the system will reach an equilibrium no matter how low the t stat is, but I was mostly worried that you might daily drive this for the reasons figgie gave. Anyways, now that you've said you'll get it...

1-2clutch-u;1813909 said:
ok so 190 on the tstat and fans come on at about the same time. what psi rad cap should I run for this?

If none of the cooling system been upgraded (I mean hoses and fittings) then stock psi, because any higher and something's gonna pop. If you can do the necessary upgrades, the higher the better (boiling temperature raises with increase of pressure).
 

IJ.

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jt2ma71;1813868 said:
I set my fans to come on at 180F and off at 178F. When cruising, temps would drop down to below 178F. At Idle, it rises, fans come on, temps go up to about 182-183 and start to drop down again so fans just shut on and off. This was all after the switch to TRD thermostat.

side topic, I will be installing a race grade dual output solid state relay to control the fan speeds depending on temp and road speeds. Good idea or not?
Great idea!

You can ramp up the fans so there's no huge inrush of current to drive them, in my LS Swap with 4x Fans it would nail the 140amp alternator if everything hard started... :aigo: