eTorque motor/generator

[nsxmugen]

I been thinking the last few weeks about the mild hybrid tech and EV conversions. There is a lot of tesla EV conversion kits and I'm sure it would be one off if someone would do it on nsx, but what spark my interest are the motor/generators that are belt driven add-ons. Buick already had those on lacross since 2012 on their 4 cyl engines. It simply gives 70tq about 20hp, the tq is from 0rpms so it is a nice boost and fixes any low end tq.

GM now has 3 models of mild hybrid 70tq, 90tq and 120tq on their V8's. Idea is simple, it's belt driven assistance to crank so it's simple and less complicated then turbo or supercharger. System has battery pack that recharges when it needs to. This preserves engine basically stock with the addition of the motor/generator, it would wear out the clutch a bit more. It would need custom adapter plate and some modding but I'm confident I can make it physically fit in there, after looking at some pics.

My electrical experience is limited and was wondering if anyone has some experience with hybrid systems. Specifically in the control module. I need some reality check but looking at the lacross system for example the motor/generator has only 3 phase leads to battery pack where the DC/AC converter is and the controller. Battery is air cooled, motor/generator is water cooled. The controller must somehow read the load/rpm from either pedal/thorttlebody/engine, check the temp of motor/generator and batteries to control venting air on batteries or turn on waterpump for motor/generator. Some of the things could be figure our by try and error I just don't know if the battery pack controller is canbus and need to see car's BCM as communication bridge and if there is any component security like VIN matching on modules or even instrument cluster. Worst case if it's using 24C64 eeprom it can be read with programmer in binary format then the section for security can be FFFFF out and written back but it might be show stopper if GM spend some time engineering it. There might be aftermarket controllers out there but I don't know what could work with it. I'm thinking if it's electricity it can be managed somehow. This might be way over my head but I like challenges and trying to chip at this little by little for more information. If anyone has some info on this or correct me on something, please do.

Thx,
David

 

[Miner]

My daily driver is a Volt, and is more complex than a BMW.
I would say adding the system to a car would be way more hassle than its worth. Grafting a complete power train into a different chassis would be complex, but more viable.
As you appear comfortable with the CAN bus, that is a starting point.
Cooling of the motor, load, throttle, etc all must be figured out and managed.

 

[Old Guy]

Interesting idea. I haven't set foot in a GM showroom since the Buick Century turbo came out, so I am completely out of touch with Buick / GM hardware. I was aware that they had implemented auto shut down / start just because I had heard the engines shutting off at stop lights; but, assumed it was the more conventional system that has been around in Europe for a long time.

I have no idea what the parasitic power losses in a Lysholm / Autorotor style supercharger are; but, they are not trivial so delivering a non trivial amount of additional power to the engine through a toothed belt drive on the front end of the engine does seem within the realm of possibility. Since I haven't set eyes on the Buick's eAssist hardware, I do wonder about the form factor of the electric motor/generator. Even water cooled, I am guessing it is going to be significantly larger than the NSX alternator. The NSX alternator is sort of around 1.5 kW, the advertising puts the eAssist package around 15 kW. If its water cooled the packaging might be smaller; but, I struggle a bit with fitting it. For a given power level, the form factor of an electric motor / generator changes with its design operating speed. Generalizations can be dangerous; but, for the same power level higher speed motors tend to be long and small diameter and slower speed motors tend to be short and larger in diameter. A custom designed high speed electric motor might fit within the confines of where a Comptech supercharger is located. Unfortunately, I expect that you are probably thinking more about repurposing some existing hardware rather than dropping a large amount of $$ on a one-off motor development. The starter / generators on aircraft turbines might be an interesting place to shop - they scream at pretty high RPMs and have high power densities.

If you want to forgo the auto shut down / start feature that could simplify the control hardware and control strategy. Skipping the regenerative braking feature would also simplify the control strategy. If all you want to do is boost power, it you used an aftermarket ECU with a viewable fuel map, it should be possible to create an equivalent eAssist map that generates an output to activate the eAssist motor in specific engine operating zones. The eAssist map would probably be very much like a Vtec operating map. In this mode of operation the eAssist essentially follows the gas engine and would be 'all in' or 'all out' in specific operating cells in the map. You would need some sort of monitor function on the eAssist so that you don't cook the electric motor or damage the battery. Theoretically most modern aftermarket ECUs probably have the hardware horsepower to manage this function; but, aftermarket ECU vendors don't exactly publish their firmware so adding the code to carry out this function is going to be 'hard'. Probably better to implement this monitoring function is a separate eAssist dedicated controller.

From you description, the eAssist motor sounds like a 3 phase alternating current motor with the drive electronics converting battery DC to variable frequency 3 phase AC. The more common control strategy would be to control the drive output frequency to control the motor electric motor speed. If you go with the eAssist map strategy using the output from the ECU to determine eAssist then the gas engine sets the electric motor speed and the electric motor just needs to output power and not worry about controlling speed. This is fairly 'simple' to do by setting up the drive electronics to control the current to the motor, presumably at its maximum design limit which maximizes the electric motor output. If you have a thermal model of the electric motor you could get sophisticated and allow higher current for shorter periods of time; but, that starts to get way more complicated in terms of coding the firmware for your controller. There are commercially available non vehicle drives; but, in my limited experience they have much higher operating voltages, not the weirdo 50 - 180 volt DC associated with Li Ion storage batteries. Sevcon sells drives for electric vehicles (the hardware parts) so that might be a place to explore if you are looking for something commercial. I don't know whether they sell control systems and the firmware to control their drives. Repurposing the controller hardware from some existing hybrid vehicle might work. Then you just get to battle with hacking the controller firmware to modify it to do what you want. In the case of the Buick, even if the drive hardware is separate for cooling purposes, I am betting that the eAssist control software is integrated into the ECU. Good luck with unpacking that to figure out what is going on!

Part of the control strategy would have to address when does the eAssist switch from power output to regenerating to charge the LiIon battery. I have dealt with bi directional drive electronics. I have never had to deal with integrating them with a DC battery source and all the complexities associated with managing a LiIon battery. That is completely out of my realm of experience.

A pure electric vehicle drive system (or gas engine with ECU) is a pretty trivial exercise compared to the integrated drive/ regenerative braking - hydraulic braking / battery charging / motor starting systems on modern hybrid cars. I remain amazed that things like the Prius work at all, not that they work in such a well integrated fashion.

I noted the other post discussing the proposed Orbis E-Nitrous wheel motor retrofit on the Honda Civic. A proposed $10k nets you the motors and controllers; but no battery although they claim plug and play battery integration without specifying what battery. Since they appear to be using the Zero motorcycle electric motor perhaps they are also using the Zero batteries. Integration with the existing vehicle engine control appears non existent - they provide a thumb throttle control for the electric drive. They do mention E brake; but, it is not clear whether they provide regenerative for the batteries. Orbis claims 50 hp (37 kW) for the Z-Force motors. The Z-Force batteries are 7.2 kW.hr each, so 1 battery would net you about 5 minutes or less of pedal to the metal for two Z-force motors without some regenerative braking.

An eAssist retrofit is an interesting idea; however, a factor of 10x in design complexity compared to a turbo charger / supercharger / nitrous path to more power.

 

[Stillsittinlodo27]

Hey this sounds insane and doable cause anything is with the right cash but this guy https://instagram.com/don_rpm_systems?utm_source=ig_profile_share&igshid=nr7g0va85gmd will try anything! He doesn’t get a lot of props but his work speaks for itself


Sent from my iPhone using Tapatalk

 

[MaxGeek]

What about swapping in the old V6 Honda Accord Hybrid drive train? The OP's avatar picture looks to be a J series.

Also just for kicks there is a neat Honda Civic Type-R AWD Hybrid aftermarket kit.
https://www.youtube.com/watch?v=0a9DVjxcuPM

 

[nsxmugen]

That is very good info. "Old Guy" thanks for taking your time and going over it. Thanks. There is more things to consider that I initially did not think about but this is def up my alley to thinker with. If all fails I'll stick the motor on a pole and make a wind turbine out of it for my green house lights, lol. I'm looking for good shop diagram manual for Lacross to see wiring diagrams to start with.

Yes, I'm running J32 swap but using any hybrid system from honda would not work as they are all integrated to tranny housings. This GM system is totally separate addon. I was also looking as smart car motors but they are more powerfull then GM and are very bulky. This 15Kw motor from GM 20hp/70tq in size is just larger then alternator. (The actual motor Kw, hp, tq, varies from the sources but it's ball park 20hp/70tq.) It would not replace alternator but it will sit on top like groupm supercharger or maybe in the area where the engine side fan is.

The honda type R system is nice, but there must be a lot of friction on the gears and if there is failure it could be catastrophic as it's directly on wheels. I like to watch the vid and hear the sounds but would be scared to ride that thing. Don't know why they did not go with motor connected with axle or create one large motor like drum brake that would bolt on to stock wheel hub. But I'm sure they had reasons behind it. In any case, cool looking system. Thumbs up to the guys thinking outside of the box. If they would have generic kit it might be possible to make NA1 all wheel drive..

Picture of the Lacrosse motor/generator system with battery pack, controller and inverter.

Here is a cool vid talking about the motor

 

[Old Guy]

Interesting to set eyes on the GM eAssist system. The 15 kW from the GM motor is much more believable than the 37 kW claimed for the Orbis motor. The Orbis is air cooled rather than water cooled liked the GM, so given that its size appears similar (or perhaps a little smaller than the GM) its continuous power capacity should be less than the GM motor. I found some of the claims for the Orbis system a little hard to accept. The GM system definitely looks more solid.

The tear down of the eAssist motor was interesting. His explanation of the number of poles and the operation of the 3 phase motor left me queasy. It was wrong; but, that was OK because those kinds of details are only of interest to 4th year and grad engineering students working on drive systems. I was surprised that it is a 'relatively' conventional squirrel cage 3 phase induction motor. I was expecting that it would be a 3 phase motor; but, with a permanent magnet rotor so operating in synchronous mode. GM must have had their reasons for switching to the squirrel cage / induction design; but, its not obvious to me. One upside to the squirrel cage / induction design is that if you can get into the drive firmware and alter the allowable slip frequency for the motor you have the potential to generate a lot more horsepower. An induction motor running at high slip can probably produce 5 to 7 times its rated horsepower; however, this comes with a hell of a lot of heat so you would have to be doing some serious temperature monitoring if you want it to last more than a couple of minutes. Of course, 5 - 7 times 15 kW would likely stretch the limits of that serpentine belt!

So, this has me thinking this might have some potential in an 'out there' kind of way. What are you thinking about doing - are you going to hang around the pick and pull waiting for the first crashed eAssist Buick to show up? That begs the question of what the salvage yards do with the LiIon batteries in hybrid cars. They must remove them before they end up in the yard because even a mostly discharged battery is still like a potential IED waiting to go off.

 

[dablackgoku1234]

Would a drivetrain/electronics swap from a RLX hybrid be viable? You would lose the manual transmission tho...

 

[nsxmugen]

Yea, the GM eAssist system is pretty straight forward and what made it attractive is that is easily obtainable and budget friendly. Whole cars on insurance auctions go for around 1-1.5k$ or the motor/battery pack for around 900$. I would get a whole parts car as I learn with my jswap you always miss small nic nac and getting it individually will cost more. It's like having a parts store in backyard. I been eyeing actions but the cars so far been out of state. One would hope the salvage yards would take care of liIon batteries but I seen them show up on ebay and people using them for different things like off the grid power wall for solar panels etc.. Oh, I had no idea that this squirel cage/induction design motor can be tweaked to produce more power. Maybe with after market controller. evwest.com has some interesting projects. When I get my parts car and have the motor/generator on bench table I'll reach out to them maybe if they have controller. There is a lot of things that I don't know yet but when I'll have the parts I'll know what questions to ask. I don't expect this just to run with first attempt and I bet there will be some problems to resolve on the way. For now I try to gather as much information as I can to understand this better.

The RLX system is very nice and I actually look in to it. It's a acura part going to acura car. But this has much higher price tag and lots more fabrication. It's a little over my budget. I would wish the typeR guys would do something like this. It has two electric motors coupled to gear reduction and axles go from the middle to each wheel. It's small enough to fit under the hood of NA1 and would made NA1 all wheel drive so this might work. I think the first year model of RLX with this system was on 2014 and since there is no drive shaft between the motor and rear wheels it's perfect candidate to just move the motor to front of NA1. I like the idea a lot but it's just out of my budget. One would not need to use the auto/tranny/engine from it but just the rear electric motor and batterypack.