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Discussion Starter · #1 · (Edited)
I've been trying to get some PHEV mode experiments off the ground. First attempt a couple days ago failed. I had not installed a BCM interceptor, so the battery pretty shut down after the car consumed what the BCM counted out as the capacity of a stock pack. What was i thinking - I knew better.

Got interceptor installed and got it all working this morning. I am using the Dabrowski MIMA to control the assist. The idea of course is to provide assist as needed to keep the car in lean burn as much as possible on uphill sections or, for now, when the fuel consumption display(FSD) drops off the 150 MPG peg.

I also have a FAS circuit with the MIMA and did use that when possible. I have made some temporary aerodynamic improvements which I plan to make more permanent - a big grill block and removal of the right side mirror. Tires at 60 psi.

Just starting to test so my approach was to use enough assist to keep the FCD pegged at 150 MPG, with understanding that the actual mileage achieved would be greater. Inexperienced as of now, but there is some sort of mental algorithm which must be evaluated rater continuously since there are now two sources of propulsion. While trying to hypermile as much as possible one is able to apply just enough assist to maintain a target speed of 50 mph, and a pegged FCD.

As I said, the mental arithmetic is complex and continuous so one becomes a pretty busy boy.

Results:
Measuring instrument Font Communication Device Technology Gadget


That works out to be just a hair under 181 MPG, electricity excepted.

Still working on aero, but not sure how many good testing days remain. Was 80F today.

Note that the Dabrowski MIMA is only available used, but the IMA C&C will accomplish the same, and may be superior since it can retain a setting. I think the MIMA has this function also but I haven't found how to use it.
 

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The idea of course is to provide assist as needed to keep the car in lean burn as much as possible on uphill sections
Ooooo! Neat approach!

You have oodles of amp-hours with your LTO pack, and I presume you are keeping it in lean burn on the downhills (as opposed to letting off the gas which exits lean burn) and increasing regen to maintain enough of an engine load to do this?

I really, really like the idea of adjusting IMA usage so that the engine load never gets so heavy that it exits lean burn. Are you finding that staying in lean burn is so much more efficient than regular burn that the losses incurred when you have to use the ICE to recharge the LTOs is not a big deal?
 

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I've been trying to get some PHEV mode experiments off the ground. First attempt a couple days ago failed. I had not installed a BCM interceptor, so the battery pretty shut down after the car consumed what the BCM counted out as the capacity of a stock pack. What was i thinking - I knew better.

Got interceptor installed and got it all working this morning. I am using the Dabrowski MIMA to control the assist. The idea of course is to provide assist as needed to keep the car in lean burn as much as possible on uphill sections or, for now, when the fuel consumption display(FSD) drops off the 150 MPG peg.

I also have a FAS circuit with the MIMA and did use that when possible. I have made some temporary aerodynamic improvements which I plan to make more permanent - a big grill block and removal of the right side mirror. Tires at 60 psi.

Just starting to test so my approach was to use enough assist to keep the FCG pegged at 150 MPG, with understanding that the actual mileage achieved would be greater. Inexperienced as of now, but there is some sort of mental algorithm which must be evaluated rater continuously since there are now two sources of propulsion. While trying to hypermile as much as possible one is able to apply just enough assist to maintain a target speed of 50 mph, and a pegged FCD.

As I said, the mental arithmetic is complex and continuous so one becomes a pretty busy boy.

Results:
View attachment 92907

That works out to be just a hair under 181 MPG, electricity excepted.

Still working on aero, but not sure how many good testing days remain. Was 80F today.

Note that the Dabrowski MIMA is only available used, but the IMA C&C will accomplish the same, and may be superior since it can retain a setting. I think the MIMA has this function also but I haven't found how to use it.
IMAC&C is still sold? I can't seem to find a thread/anywhere to buy it.
 

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Discussion Starter · #5 ·
Ooooo! Neat approach!
It isn't a new idea. I believe Peter talked about it a while back when discussing his IMA C&C.

You have oodles of amp-hours with your LTO pack, and I presume you are keeping it in lean burn on the downhills (as opposed to letting off the gas which exits lean burn) and increasing regen to maintain enough of an engine load to do this?
I'm just starting the experiments, and therefore still learning about technique. I actually shut the engine down on the decent downhills. Nothing boosts MPG as effectively as using a FAS circuit. I do have a baseline to test against. When I had the silver aeromodded hypermiler I could achieve 115-120 MPG on my test circuit using the same techniques minus the large boost from the LTO pack. So, the 181 is an increase of at least 55-60 MPG.

I really, really like the idea of adjusting IMA usage so that the engine load never gets so heavy that it exits lean burn. Are you finding that staying in lean burn is so much more efficient than regular burn that the losses incurred when you have to use the ICE to recharge the LTOs is not a big deal?
The main idea behind PHEV mode is NOT to allow any regeneration, or IMA battery charging. That would reduce trip MPG. So, the optimum approach is to exactly use 21 Ahr of battery on your round trip commute. That means you can have an average consumption of about 20A for a 30 minute commute with a return home. Or, if your commute is 2 hrs roundtrip, you can have an average consumption of 10A. The MPG will obviously be different for the two examples, but it will be considerably better than a "normal" baseline.

I think the required technique will differ depending on terrain. Since neither the MIMA or the IMA C&C are adaptive to load, the most optimum approach will be to use the brain to make judgements about how must battery assist to use to keep the FCD pegged and stay in lean burn. It makes for very busy driving. It may be better to just set a constant assist if the terrain is only moderately hilly as here in Richmond.
 

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IMAC&C is still sold? I can't seem to find a thread/anywhere to buy it.
Oh welp. PM time.

Also, I'm hoping I'll be able to do something similar to this with LInsight, my commute is only 20mi round trip for work, and it's mostly highway, so I'm hoping I can just use battery(with no recharge) to and from work, and charge everyday at home. Should give a nice MPG bump but we will see.
 
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Discussion Starter · #7 ·
You should be able to get an MPG bump even with the smaller Gen3 batteries being used, but the method becomes much more attractive with the LTO conversions, since they have a lot more capacity. Of course the LTO conversions have a lot of negatives currently. They are a mechanical nightmare to install, they are large and heavy, they currently have no effective BMS, and they are far from a drop-in conversion.
 

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You should be able to get an MPG bump even with the smaller Gen3 batteries being used, but the method becomes much more attractive with the LTO conversions, since they have a lot more capacity. Of course the LTO conversions have a lot of negatives currently. They are a mechanical nightmare to install, they are large and heavy, they currently have no effective BMS, and they are far from a drop-in conversion.
Yea that's why I haven't bothered with it. I don't really have time to deal with that much of a headache.

Also, how many miles are on DogBite now?
 

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This poor quality old video of mine might help illustrate how useful/good a phev can be.


IMAC&C P&P works with the OBDIIC&C nowadays, so it could be cognisant of the engine load if you select that parameter for monitoring, and it could feed in assist to try and keep the car in LB as it knows when it is/isn't. (Green led!)

But it can't control the throttle, so you still have to interact with the system and do the actual LB control bit as well.
It's a symbiotic relationship between you, your foot and the OBDIIC&C/IMA..
It can't feather the throttle for instance but it can pour on the assist/regen upto your chosen limits.

I did add a simple cruise feature to the OBDIIC&C and it will try and maintain a set speed using assist/regen with a big pack, that could be modified (maybe) to do what you are wanting.

Ten years ago we had this

A year ago we got this
 

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Discussion Starter · #10 ·
This poor quality old video of mine might help illustrate how useful/good a phev can be.
You're right about the poor quality. I think you may have encrypted the results with road noise and camera shake :ROFLMAO:

I think I was able to see that you were adjusting assist/regen with IMA C&C controls on the steering wheel. Looked like few or no real hills. Anyway, yes the same effort at synergistically controlling two propulsion sources in some sort of mental optimumization process. (Wow, that's a mouth full.)

I don't know that the process can be automated at the diy level. There are some serious impediments to doing so. First, no simple computer "sees" the road grade profile. Perhaps a road load profile, say a given commute route, could be learned by a processor over several trips and that might help, but it gets complicated.

A promising approach might be to use a "smart" soft cruise control which would create an "assist" signal when speed loss exceeds some threshold. According to Mike's MIMA theory of ops there are only 3-4 lines from the ECM to MCM which activate assist and control the amount (probably used in both IMA C&C and MIMA). This explains some of it:
.

I'm not likely to go down the automation route anytime soon. My next big project is getting my Orion installed and working. I was primarily interested in determining the MPG potential which seems considerable. Automating the rather complicated process will have to be left for smarter folks. But I will continue to experiment with operational options:)
 

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Discussion Starter · #11 ·
I can't even find any technical, or even semi-technical explanation of how the PHEV vehicles in the market even work. It would be nice to read something intelligent and not just a bunch of marketing eyewash. Anyone found anything?
 
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Discussion Starter · #12 ·
Took a while, but the light finally went on. Since only Honda seems to have lean burn technology, the considerations for Gen1 MT electrical augmentation are entirely different for all other manufacturers. LB changes the entire equation. For others the design is much more simple - simply install as much battery as is economically and technically practical and then run on electricity only for the resulting 40-80 miles. That distance covers a lot of two way commutes and therefore becomes a big environmental positive.;)
 

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Discussion Starter · #13 ·
120 MPG on 2 mi round trip to grocery store-cold car. Only ran the ICE in background. Lots of potential here for short city trips of maybe 10 miles with stops, lights, traffic, etc.

Pretty busy with all the controls.;)
 

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I can't even find any technical, or even semi-technical explanation of how the PHEV vehicles in the market even work. It would be nice to read something intelligent and not just a bunch of marketing eyewash. Anyone found anything?
Most work just like an EV on battery
and just like a normal hybrids on gas

There are explanations of the Volts modes of operation with deep dives, even a famous engineer has tore them down
 

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Awesome to see. I haven't seen 150 MPG in my car in several years, but it's on my list of things to commercialize post-LiBCM.

One concept I have is "lean control" which is similar to cruise control, except that the car provides as much assist as is necessary to prevent the ECM from dropping out of lean burn. The inputs are throttle position, fuel trim, etc. That way you don't have to constantly think about whether to push the gas or the assist lever.
 

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Awesome to see. I haven't seen 150 MPG in my car in several years, but it's on my list of things to commercialize post-LiBCM.

One concept I have is "lean control" which is similar to cruise control, except that the car provides as much assist as is necessary to prevent the ECM from dropping out of lean burn. The inputs are throttle position, fuel trim, etc. That way you don't have to constantly think about whether to push the gas or the assist lever.
What about during purge cycles?
 

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Jimmy, I may have to take you up on a 1 liter/100km, 235 mpg, challenge! The best I've gotten in PHEV mode is 125 mph over a total distance of 777 miles. These were short trips during COVID, so it took several months. The battery voltage was within a range of 202 -217 V most of the time.

The Dubrowski charger recharges this battery at about 3 V/hr at 1070 mA, but only about 1 V/hr at 346 mA. Lately the charger has been having issues getting through the 202 V barrier at 1070 mA, but it doesn't have a problem making it through at 346 mA. If start-of-charge Voltage is less than 202 V, an alternate profile, with 202 Voltage cut-back, is selected. Once the Voltage climbs above 202 V, the charger can be switched back to the normal profile, with cutback and end-of-charge voltages both set in the 218 - 220 V range.

When the battery taps are well balanced, within 0.0 - 0.1 volts per 6-cell tap, then I have charged to 222 V. The voltage drops to just under 219 V after end-of-charge. The battery voltage can be brought back down early in a drive by using lots of assist in combination with neutral braking to keep the DC-DC converter happy.

I plan to do another battery-pack capacity test before long to see how much LTO battery degradation has occurred during the past 2 years.
 

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"PHEV mode is 125 mph over a distance of 777 miles". Now that is hauling butt for a long distance. LOL
 
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