LS3 Temperatures for Fan Kick On/Off?

wesinls

wesinls

Well-known member
Joined
May 6, 2021
Messages
652
Reaction score
808
What temperatures are you or do you recommend kicking the radiator fans on? Both on at the same time, one on then the 2nd only if temps rise to x degrees?  In my view I feel I should kick them both on close to each other (to avoid a large amp draw all at once) - then all off at 180.  Currently I have them coming on at 194 / 195 then off at 180...they will prob never turn off once I'm driving around.

Curious what others are doing.

Ty!

 
I like mine to start early.  I want to know a least one is working before i leave camp, I have one come on at 140 and my other one comes on at 160, my thermostat is a 160, it is hard on the alternator to have both kick at the same time. if you have a system when both are paired together, then you can do a relay that has a delay setting to help separate the power serge.

 
J Alper said:
I like mine to start early.  I want to know a least one is working before i leave camp, I have one come on at 140 and my other one comes on at 160, my thermostat is a 160, it is hard on the alternator to have both kick at the same time. if you have a system when both are paired together, then you can do a relay that has a delay setting to help separate the power serge.
Click to expand...
Ty, good point on wanting to confirm before leaving camp.

 
Depends on your radiator size and fan CFM and or course airflow

But in general if you are not running a thermostat I have found the best course is to turn the first fan on at 185 and off at 180 and the second fan on at 190 and off at 180

 Like @J Alper said staggering them is easier on the electrical system

The right size cooling system should bring ther temps under contriol pretty quick

You don't want to run the car too cold assuming you are running an oil with a Zinc or Phosphate additive (like VR1 ior phosphate in Mobil 1)  you need to keep the engine over 170 or it has no benefit.  Over  200 is hard on the oil  as the oil temps will be over 220  

Also if you run am 18 or 20 lb cap you will have a bit of extra over heat protection if you get a heat spike.

 
Figured I should share what I have - changed fan 1 based on Alper's info. (Thanks again)

I updated my settings on the terminator X today to be:
Radiator fan one - on at 165 off at 160 (will prob never turn off I'd assume) - fan 1 on hot side of the radiator
Oil cooler fans on at 170 off at 160 
Radiator Fan 2 - on at 195 off at 180 (might change this to be like 185 off?)

I haven't driven it yet so curious to see if fan 2 will ever turn on once I'm able to get a nice hard run...If it won't stay at or close to 180 I'll be making adjustments....Also plan to add an oil temp sensor - there's a turbo gauge on the car now that I'm not using, might as well put a gauge there.

 
I have mine come on at 195.

Oil cooler fans are on all the time.

Running hard, my radiator shows around 205-215.

Oil temps are 230-240.

Once I slow down/stop, engine temps drop to 195 pretty quick.

 
wesinls said:
Figured I should share what I have - changed fan 1 based on Alper's info. (Thanks again)

I updated my settings on the terminator X today to be:
Radiator fan one - on at 165 off at 160 (will prob never turn off I'd assume) - fan 1 on hot side of the radiator
Oil cooler fans on at 170 off at 160 
Radiator Fan 2 - on at 195 off at 180 (might change this to be like 185 off?)

I haven't driven it yet so curious to see if fan 2 will ever turn on once I'm able to get a nice hard run...If it won't stay at or close to 180 I'll be making adjustments....Also plan to add an oil temp sensor - there's a turbo gauge on the car now that I'm not using, might as well put a gauge there.
 
Click to expand...
If you have a Holley, it displays on the screen if your fans are on, and you can just set a huge timing retard on temps above 220*F (or whatever you want that's above normal on a warm day) so you'll stop on overheat quickly.  The quicker you get up to temp, the quicker you burn things out of the oil, so if you're not running a thermostat, the above settings might not be ideal on night runs or cold days.  

 
Man, sounds like the Holley terminator is the way to go. I need to start some research on this for my car. 

 
BONES said:
Man, sounds like the Holley terminator is the way to go. I need to start some research on this for my car. 
Click to expand...
Best bang for the buck - has all the features you will ever need and they actually all work and are relatively easy to set up

like anything else there are a few "gotchas". but compared to anything shy ion a Motec at 10x + the price nothing is more accurate or provides better control.

The SW keeps getting better.  the next update will be great  adding more of the HP/Dominator 6.0 features 

 
BONES said:
Man, sounds like the Holley terminator is the way to go. I need to start some research on this for my car. 
Click to expand...
the only thing with the Terminator about 20% of them that we used have software issues, so it does take time to get the tune in from a laptop, I use them a lot but really like the HP unit, it is potted and has larger mosfets in them, 

 
Fullthrottleguy said:
Best bang for the buck - has all the features you will ever need and they actually all work and are relatively easy to set up

like anything else there are a few "gotchas". but compared to anything shy ion a Motec at 10x + the price nothing is more accurate or provides better control.

The SW keeps getting better.  the next update will be great  adding more of the HP/Dominator 6.0 features 
Click to expand...
Will the next one have Thermo control on the imputs, I know you can use a pullup resistor and make one by tapping into the 5v, but what a pain it is, it would be nice to have a one click temp sensor add to the Terminator, 

 
Just curious....what temp is the stock thermostat?

 
J Alper said:
Will the next one have Thermo control on the inputs, I know you can use a pullup resistor and make one by tapping into the 5v, but what a pain it is, it would be nice to have a one click temp sensor add to the Terminator, 
Click to expand...
Jason, thats a HW change they are not going to do as far as I know for additional temp sensors -  using a pull up and tapping 5V is not straightforward, but its not hard.  Additional temp usually just a "convenience" since all engine temps are driven by water temp

Personally I think the shortcoming is not having a second o2 sensor - another HW change- I want to see each bank -  the tune is everything in keeping the engine alive - nothing kills an engine faster than a bad tune up IMO

 
J Alper said:
Will the next one have Thermo control on the imputs, I know you can use a pullup resistor and make one by tapping into the 5v, but what a pain it is, it would be nice to have a one click temp sensor add to the Terminator, 
Click to expand...
https://www.holley.com/blog/post/how_to_add_additional_inputs_outputs_to_an_hp_terminator_x_or_dominator_ecu/

There's the I/O module as well.  $400 ish for the kit.

https://www.holley.com/products/fuel_systems/fuel_injection/modules_and_sensors/can_input_output_module/parts/554-165

 
Last edited by a moderator:
Rockwood said:
https://www.holley.com/blog/post/how_to_add_additional_inputs_outputs_to_an_hp_terminator_x_or_dominator_ecu/

There's the I/O module as well.  $400 ish for the kit.

https://www.holley.com/products/fuel_systems/fuel_injection/modules_and_sensors/can_input_output_module/parts/554-165

Or the 7" dash can display these inputs if you don't need to datalog or set conditions.
Click to expand...
Rockwood -  the issue is usually not the number of inputs - its the type ofdinputs

the 7" dash is basically Stone Age  - the Pro Dashes are 6.86 and 12.9 and this easier and faster to add inputs, but they are all the same type issues 

 
Fullthrottleguy said:
Rockwood -  the issue is usually not the number of inputs - its the type ofdinputs

the 7" dash is basically Stone Age  - the Pro Dashes are 6.86 and 12.9 and this easier and faster to add inputs, but they are all the same type issues 
Click to expand...
Yeah, edited out the 7" dash since it's not really useful here.

I believe the I/O has the ability to add all the different thermistors you'd want, no?

image.png

 
someone should just make a thermal sensor with a pullup sensor wired in,   you can do a small pig tail potted in and a connector to a 3 wire, that would sell good i think,  

 
J Alper said:
someone should just make a thermal sensor with a pullup sensor wired in,   you can do a small pig tail potted in and a connector to a 3 wire, that would sell good i think,  
Click to expand...
Like a 3 wire? :biggrin:

instrumentationtools.com_rtd-connection-diagram.jpg


 
You must log in or register to reply here.
Back
Top