Electronic Thermostat Control Retrofit: What is temp worth?

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NewbVetteGuy
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Electronic Thermostat Control Retrofit: What is temp worth?

Post by NewbVetteGuy »

Just thinking about newer engines that use electronic thermostat control to enable an engine to come up to operating temp sooner, run hotter cruising down the highway to improve fuel economy, and then switch to running cooler as RPM, MPH, or engine load goes up via ECU control and what dynamic control of engine temps is "worth" from a MPG perspective?

Anyone have any studies on MPG of running a 160 F thermostat vs. a 180F vs. 205F? (I've heard plenty of internet anecdotes claiming +1-+2 MPG or up to 10%, even crazy claims of +20% mpg improvement, but I am just not sure what is a reasonable expectation.


Anyone aware of any retrofit electronic thermostat control options?


I love the idea of being able to push the edge of your octane limitations and keeping temps cool to stay out of trouble when the weather gets hot, but instead of using an octane booster in hot weather, what if you could just tell your electronic thermostat to drop the temps in troublesome areas of the map and crank the engine heat up at highway cruise RPMs to keep MPG up when you can?

These guys seem to have solutions in this space that main look like they focus on electronic control of their electric water pumps and electric fans. An electric retrofit thermostat seems so much more simple, though... https://daviescraig.com/?gclid=Cj0KCQjw ... 1_EALw_wcB




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Re: Electronic Thermostat Control Retrofit: What is temp worth?

Post by PackardV8 »

I have no recent experience with Davies-Craig, because I bought their first iteration electric water pump; it was a plastic toy I couldn't imagine trusting on any build. Possibly, their products have improved.

As to benefits of coolant temperature mapping, GM Engineering spent much effort to achieve this on their new 3-cylinder turbo engines. Much of it was aimed at immediate warm-up for emissions compliance.
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Re: Electronic Thermostat Control Retrofit: What is temp worth?

Post by NewbVetteGuy »

PackardV8 wrote: Mon May 10, 2021 1:43 pm I have no recent experience with Davies-Craig, because I bought their first iteration electric water pump; it was a plastic toy I couldn't imagine trusting on any build. Possibly, their products have improved.
Thanks. I saw a review of their electric water pump + fan controller that basically called it more of an electronic experiment vs. a complete product...

I don't think I want to give them any of my money. Only highlighting the only single company I've heard of in this space.
Installing an off-the-shelf electronic thermostat from something else that would work and controlling it via some hacky Holley EFI integration or simple stand-alone controller would, IMO be way better.

Even being able to just have a toggle switch that could go between 180F and 205F would be an improvement vs being stuck with a single temp.
(I've already got a dash-mounted toggle switch for my TCU to switch between "ecomode" shifting and "performance mode" shifting. -Having the same switch make the electronic thermostat switch to 205F in ecomode and 180F in performance mode would be good enough for a min-bar, but something smarter is better.



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Re: Electronic Thermostat Control Retrofit: What is temp worth?

Post by PackardV8 »

NewbVetteGuy wrote: Mon May 10, 2021 3:20 pmEven being able to just have a toggle switch that could go between 180F and 205F would be an improvement vs being stuck with a single temp. Adam
Why stop at 205? Some of the last SBCs didn't even turn on the electric fan until 230.
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Re: Electronic Thermostat Control Retrofit: What is temp worth?

Post by NewbVetteGuy »

PackardV8 wrote: Mon May 10, 2021 4:00 pm
NewbVetteGuy wrote: Mon May 10, 2021 3:20 pmEven being able to just have a toggle switch that could go between 180F and 205F would be an improvement vs being stuck with a single temp. Adam
Why stop at 205? Some of the last SBCs didn't even turn on the electric fan until 230.
I have an 8.4 DCR so I fear going any higher. Another reason I'd love to be able to dynamically adjust when the thermostat kicks open.


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Re: Electronic Thermostat Control Retrofit: What is temp worth?

Post by NewbVetteGuy »

Hmm...

What do you know, you can approximate electronic thermostat control with Holley EFI by using one of the Holley's custom PWM outputs -send this to a 12v solid state relay and control the duty cycle out to the electric pump...

Apparently Davies Craig holds an incredibly broad patent about using an ECU to provide a PWM signal to throttle a water pump to control engine temps?!? Patent office asleep at the wheel...

https://forums.holley.com/showthread.ph ... ed-Control

A C6 Corvette fan controller is commonly inserted between the Holley ECU and electric fans OR electric water pumps, too.

The standard SBC 35 GPM Meziere pump only requires a peak 7 amps, my electric fan 14 amps at full speed and the C6 controller supports 30 amps. (As long as I keep it cool enough, it should be good.)


My more serious hobby is beer brewing and I built my own custom 3 vessel electric brewery and controller so I'm more than comfortable with PWM control and SSRs and sizing the electric loads and cooling requirements.

Now just to contact Meziere and see if their pumps can safely be throttled like this although I probably should test it out with a cheap Chinese pump incase I kill it... (I figure never have it spin less than 10% of max speed.)



I'm actually incredibly excited about this! This is the kind of project I really like!


Adam
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