# So uh, is anyone working on hacking the model 3 drive unit?



## brian_ (Feb 7, 2017)

It's just a guess, but would expect that your last possibility is the case: just not a lot in the salvage system yet. I'm not a Tesla expert, but in this forum I've never even heard of a single person attempting to use Model 3 hardware, although a few have been torn apart (while making videos) so there are a few out there.

One detail that may be important: the Model S and X drive units all place the motor behind the axle line, but the Model 3 rear drive unit places the motor ahead of the axle line (like most other EV drive units). That matters to packaging the drive unit into the car, and to interference with the suspension components and structure.


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## Davey B (Jun 22, 2019)

I’ve been in contact with EV West over the past year about their development of an aftermarket dual Tesla motor controller (although they didn’t say whether it was a model 3 or not). It’s been a couple months from completion for the past year until just recently... now it’s about 6 months out lol. 

I’m patient, but rest assured someone is working on it and I’m glad it’s these guys because they already have a working Tesla motor and aftermarket controller. It should be too much longer.


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## brian_ (Feb 7, 2017)

BMActual said:


> Is EV West developing a controller for the standard Dual Motor setup with Tesla’s Primary and Secondary Motors or will it have the ability to run a Primary on both axles?


I find that to be a strange way to refer to the Tesla Model S/X drive units; the large unit is only used at the rear, and is the only unit used by itself (non-AWD), but does that make it "Primary"? The small units come in two package styles (for the front and for the rear), and the small rear unit is only used in combination with the front unit (AWD or "dual motor"), but does that make them "Secondary"?


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## brian_ (Feb 7, 2017)

BMActual said:


> Sure, the technical term would be LDU & SDU if we’re talking about the Model SX series motors. But this is somewhat complicated by the fact that in April Tesla began stuffing a Model 3 permanent magnet motor into the front of SX’s and a regular induction LDU in the rear to achieve 370 mile range on a 100kWh pack.


I had heard that the Model 3 front motor was unlike the rear motor, but not that Tesla was using a Model 3 front unit in the Model S/X. 

It would be very strange to use a PM motor in the front and an induction motor in the rear of a vehicle which routinely drives only the rear, because if one motor is to be spun unpowered, it should be the induction motor. Various sources have reported that the Model 3 AWD has an induction motor in the front, in contrast to the PM rear motor.

In any case I don't think that makes much difference.



BMActual said:


> I used Primary/Secondary in reference to the all wheel drive system in the dual-motor model as it distributes available electrical horsepower to maximize torque (and power) in response to road grip conditions and weight transfer in the vehicle. For instance, during hard acceleration, weight transfers to the rear of the vehicle. The front motor (secondary) must reduce torque and power in order to prevent the front wheels from spinning. That power is fed to the rear motor (primary) where it can be used immediately. The opposite happens when braking, when the front motor can accept more regenerative braking torque and power.


Like all things Tesla, this is nothing new. Every AWD system distributes power between axles in a manner appropriate to driving conditions, and to the different characteristics of the drive hardware. Both the position (front or rear) and (in some cases) the type of motor (induction or PM) are relevant.

Yes, a proper aftermarket AWD solution will need to manage the two drive units in proper coordination.



BMActual said:


> The rear motor is the primary drivetrain used for acceleration. If you were to take (2) LDU units and fashion a dual-motor setup, you wouldn’t refer to them based on size, but rather by their position or by their role.


Yes, "front" and "rear" would make sense functionally. What could not under any condition make sense would be calling both motors in the same vehicle "primary", as in this:


BMActual said:


> Is EV West developing a controller for the standard Dual Motor setup with Tesla’s Primary and Secondary Motors or will it have the ability to run a Primary on both axles?



The motors themselves (and presumably the corresponding controllers and inverters) have so far come in

original Roadster induction
large induction S/X
small induction S/X (in front-mount and rear-mount packages)
PM (only found in rear of Model 3)
new induction (possibly in Model 3 Model S/X variants)


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## brian_ (Feb 7, 2017)

BMActual said:


> Kinda getting wrapped around the axles here in relation to the Primary/Secondary nomenclature here. If I’ve got two axle-mounted motors in a vehicle, I’d refer to them as such regardless of size, motor-type, etc.


As what? "Front" and "rear"? Sure.  Just don't call them both "Primary", because one is from the rear of a Model 3 (where it is obviously "primary" in a 2WD Model 3), and the other is any Model S/X rear unit (which is obviously "primary" in a 2WD Model S/X). And you can call the one in the rear of your specific application "primary" and the other one "secondary", but you'll have to explain that to everyone, every time, while "front" and "rear" is clear and obvious. A front-heavy vehicle with a large front motor and small rear motor might even reverse the priority, so that the front is primary and the rear is secondary (as is the case in most AWD engine-driven vehicles).



BMActual said:


> At any rate, fingers crossed that EV West’s controller can be used as I’m very fond of their work and are somewhat local.


I'm sure they'll say that whatever they make is perfect for your application. While AWD production EVs are becoming common, and AWD custom and race cars exist (e.g. 2019 Pikes Peak Racecar), I haven't heard of an off-the-shelf aftermarket offering using salvaged production EV components... and that makes sense, because generally the aftermarket/DIY stuff (in EVs, but even in gas engine vehicles) is not nearly as advanced as production vehicles (e.g. no stability control, or even ABS). One issue is that a vehicle is a complex thing with many interdependencies between systems and aspects of the vehicle design, so it is unreasonable to expect one aftermarket solution to work properly for whatever you put the bits in (i.e. a race car, a rock crawler, and a street pickup truck could all use the same motors and controllers).


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## brian_ (Feb 7, 2017)

Back to the original question...

Has anyone heard of a hack of the Model 3 rear drive unit (the one with the PM / "switched reluctance" motor), by any approach (external control unit talking to stock inverter/controller, replacement or modified controller board in inverter...)? It's probably still early.
Has anyone heard of a hack of the Model 3 front drive unit (the one with the induction motor), by any approach? That will be even less likely.


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## ViktorT (Jun 26, 2019)

Hi. I post a follow up question here on the tesla drive unit string. I have a fron drive unit I want to use in a front wheel drive car. Now in the car the steering axle is behind the drive axle but the tesla drive unit is tilted inwards about 45deg making it difficult to fit (I want to fit it directly on to the existing drive axle. Is it important the way the tesla drive unit is tilted? If I were to place it with only say 15deg angle inwards it would make it much easier


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## joekitch (Sep 13, 2013)

as a follow up to the original question posed, i emailed EVControls about their T-1C motor controller (the one ev west sells, and the one i'm planning to use for my conversion) and if it'll support the model 3 performance rear drive unit at some point

http://www.ev-controls.com/product/ev-controls-t-1c/

they wrote back saying that it's on their roadmap, but no ETA at the moment. I'm hoping it's a same-time-next-year thing

I also asked if they're going to support having custom LCD gauge clusters like what Motec does with their ECUs
https://www.motec.com.au/c1212/c1212overview/

to which they said yeah, they're working on "wireless support for and android based gauge display"


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## Dillzilla (Aug 6, 2021)

joekitch said:


> it's apparently better than the original model s drive unit in almost every way, including way better cooling.
> 
> however, the older units have been hacked such that open controllers can talk to the inverter and motor THROUGH the tesla controller instead of replacing it.
> 
> is there any progress on doing the same but for the m3 du? Is it so obtuse that it'll take years to make it happen? Are there too few examples in junkyards so far to really mess with?


I know that is something going on at openinverter.org they managed to override the existing firmware on the control board, effectively allowing you to reprogram the entire motor.


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