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Lower Temp Thermostat

jetrinka said:
Well then I'd say that either your race vehicles have hardware that doesn't agree with your tuning, or your tuning sucks, or perhaps both.

As someone posted earlier the thermostat has an internal heater capable of opening the thermostat at a much lower temperature than otherwise when high load conditions exist. I guess I'll throw you a bone - here is some literature straight from Ram.

"THERMOSTAT OPERATION: The Electric Heated thermostat operates as a dual function thermostat. During normal engine conditions the thermostat operates exactly like a typical high temperature thermostat. When the engine reaches approximately 102°C (215.6°F) the wax pellet expands and the thermostat begins to open. The thermostat will be fully open at approximately 115°C (239°F). When engine load is increased and the PCM requires increased engine torque, the PCM energizes the electric heater inside the thermostat which causes the thermostat to start to open at 85°C (185°F). The PCM controls the thermostat heater operation with a High Side Driver (HSD) Control."

It seems that you can have your cake and eat it too.
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I don’t think I have seen this information before thanks. :)

Also I wonder what a “High Side Driver (HSD) Control” is?
 
dieselscout80 said:
I don’t think I have seen this information before thanks. :)

Also I wonder what a “High Side Driver (HSD) Control” is?
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It’s weird wording and I’d have to check a wiring diagram but I believe it means the high amperage needed to heat the element in the thermostat is controlled via a relay commanded via the PCM. I can see if I can find a diagram later to be sure.
 
jetrinka said:
It’s weird wording and I’d have to check a wiring diagram but I believe it means the high amperage needed to heat the element in the thermostat is controlled via a relay commanded via the PCM. I can see if I can find a diagram later to be sure.
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Curious since it can be actuated open at 185* according to your post if I could command it to open at 185 all the time and not just under load. Would have to get into HP tuners and poke around. Would save money not having to replace it.

Are you aware of any oil cooler kits made for these trucks? Only seem to find 6.7 kits or generic universal kits. Universal wouldn't be any issue but if there's something made with specific mounts id opt for that.
 
trizzle said:
Curious since it can be actuated open at 185* according to your post if I could command it to open at 185 all the time and not just under load. Would have to get into HP tuners and poke around. Would save money not having to replace it.

Are you aware of any oil cooler kits made for these trucks? Only seem to find 6.7 kits or generic universal kits. Universal wouldn't be any issue but if there's something made with specific mounts id opt for that.
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I think you’re missing the point. The HD 6.4 thermostat is designed to open and stay wide open during high load conditions such as towing or (I suppose) racing. The only way you’re getting higher flow through it is gutting the thing.
 
jetrinka said:
I think you’re missing the point. The HD 6.4 thermostat is designed to open and stay wide open during high load conditions such as towing or (I suppose) racing. The only way you’re getting higher flow through it is gutting the thing.
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No, i completely understand it stays open under load with what you posted. I was thinking out loud wondering if HP tuners had a table made for the thermostat in the HD pickups to keep it open at 185 (or whatever i want to set it at) ALL the time. Would make changing it out null since its PCM controlled at that point. Im guessing there would have to be a table for the heater there as well otherwise fans speed setting would be fighting the heating element 24/7.

I dont plan on racing this thing either. Its an 8000lb pickup and I much prefer my 4800lb charger.. lol
 
trizzle said:
No, i completely understand it stays open under load with what you posted. I was thinking out loud wondering if HP tuners had a table made for the thermostat in the HD pickups to keep it open at 185 (or whatever i want to set it at) ALL the time. Would make changing it out null since its PCM controlled at that point. Im guessing there would have to be a table for the heater there as well otherwise fans speed setting would be fighting the heating element 24/7.

I dont plan on racing this thing either. Its an 8000lb pickup and I much prefer my 4800lb charger.. lol
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Seems like a lot to worry about, considering the void of benefits for said move.

Let us know how it turns out.
 
trizzle said:
Curious since it can be actuated open at 185* according to your post if I could command it to open at 185 all the time and not just under load. Would have to get into HP tuners and poke around. Would save money not having to replace it.

Are you aware of any oil cooler kits made for these trucks? Only seem to find 6.7 kits or generic universal kits. Universal wouldn't be any issue but if there's something made with specific mounts id opt for that.
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I Don’t know if it could be commanded.

That said when my thermostat was not closing the coolant was running at about 187 degrees and I noticed my fuel mileage went down.
 
trizzle said:
No, i completely understand it stays open under load with what you posted. I was thinking out loud wondering if HP tuners had a table made for the thermostat in the HD pickups to keep it open at 185 (or whatever i want to set it at) ALL the time. Would make changing it out null since its PCM controlled at that point. Im guessing there would have to be a table for the heater there as well otherwise fans speed setting would be fighting the heating element 24/7.

I dont plan on racing this thing either. Its an 8000lb pickup and I much prefer my 4800lb charger.. lol
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Thermostats control the minimum temperature of the coolant and regulate the amount of flow through the whole system. Cooling systems are also usually overbuilt in order to accommodate less than ideal conditions and situations where a fully open thermostat is required. The heater in the thermostat is there to fully open the thermostat at the whim of the PCM when it see's or anticipates a high load on the cooling system. Using this feature in a regular driving situation would likely result in the coolant temperature dipping well below your 185 degrees and staying there. There's a reason P0128 codes pop up when a thermostat sticks open.

I'd also imagine commanding that heating element on for a considerable length of time would eventually load the circuit enough that something would fail. Logic says it likely doesn't stay heated up - once the coolant from the engine reaches the requisite temperature of the thermostat to stay fully open I'd imagine the heater turns off.

Your quest for cooler temperatures for no good reason on your street driven truck makes absolutely no sense.
 
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dieselscout80 said:
I don’t think I have seen this information before thanks. :)

Also I wonder what a “High Side Driver (HSD) Control” is?
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Here is a wiring diagram. It appears they are just using the term high side meaning a driver in the PCM that controls B+ to the thermostat heater (called an actuator). Its a straight shot from the PCM to the heater. Once through the heater the circuit goes to an engine ground.

This is specific to my 21 Power Wagon. No idea if other years are the same.
 

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jetrinka said:
Thermostats control the minimum temperature of the coolant and regulate the amount of flow through the whole system. Cooling systems are also usually overbuilt in order to accommodate less than ideal conditions and situations where a fully open thermostat is required. The heater in the thermostat is there to fully open the thermostat at the whim of the PCM when it see's or anticipates a high load on the cooling system. Using this feature in a regular driving situation would likely result in the coolant temperature dipping well below your 185 degrees and staying there. There's a reason P0128 codes pop up when a thermostat sticks open.

I'd also imagine commanding that heating element on for a considerable length of time would eventually load the circuit enough that something would fail. Logic says it likely doesn't stay heated up - once the coolant from the engine reaches the requisite temperature of the thermostat to stay fully open I'd imagine the heater turns off.

Your quest for cooler temperatures for no good reason on your street driven truck makes absolutely no sense.
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Im very aware of how an engine and its cooling system works. No codes if you tell the pcm that the desired temps are within limits. Easy change in any tuning program. MY experience has been nothing but positives with a lower thermostat in every hemi ive owned. You dont have to try to understand why I want it. Thats the joy of having your own vehicles. Do what you want with them.
 
Well folks, this topic has come to a dead end with not a whole lot past most of yall being twats with no good information. Hopefully not all of the 2500 forums are full of dick swingers hell bent on trying to shut down any idea other than "do 35s fit on my 2500 with a lift" style questions. Cheers.
 
trizzle said:
Well folks, this topic has come to a dead end with not a whole lot past most of yall being twats with no good information. Hopefully not all of the 2500 forums are full of dick swingers hell bent on trying to shut down any idea other than "do 35s fit on my 2500 with a lift" style questions. Cheers.
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Well, based on your snarky responses, I think peeps are of the opinion that “If you and your tuner are so smart, figure it out yourselves”.
 
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