# EM57 Subaru BRZ



## Dala (Jan 10, 2018)

Spline diameters available here: Which friction disk to match Leaf splines - openinverter forum

If you go EM57 route, I heavily recommend the Resolve-EV Controller!


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## vwbrady (Feb 13, 2020)

Dala said:


> Spline diameters available here: Which friction disk to match Leaf splines - openinverter forum
> 
> If you go EM57 route, I heavily recommend the Resolve-EV Controller!


Gee I wonder why??


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## Electric Land Cruiser (Dec 30, 2020)

Are you planning on keeping the transmission or ditching it? Good reasons for both but the BRZ has a ton of aftermarket support including high-ratio final drive gears so possibly direct driving from the EM57 to a 5.28:1 or higher diff would give you excellent performance and good top speed too.

I think a BRZ is a great candidate as long as you can find room for batteries!

+1 for Resolve-EV I also have one and very impressed so far.


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## vwbrady (Feb 13, 2020)

also height for the Power module stack. unless you split them, which is doable. but if you split them then it's less reasonable because the Charger and DCDC are huge for what they do.


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## YumYum (Jul 1, 2020)

Dala said:


> Spline diameters available here: Which friction disk to match Leaf splines - openinverter forum
> 
> If you go EM57 route, I heavily recommend the Resolve-EV Controller!


I took a look through this thread and it seems similar to other threads I have read here, which would be repurposing a friction disk. I was hoping to find the JIS spline spec to model my own part. Regardless, that is one of the first things I will have to figure out.

As for the controller, it would have been nice to know about your solution back before I bought my parts. I do have the Leaf charger module but I believe it is the 3.3KWh which doesn't have DC charging. I got it as with the motor but I was going to use my own charger and DC-DC. For now I have a thunderstruck VCU which I probably won't be using since it will be difficult to integrate with my intermediary computer and the rest of the car.

I will be using the manual transmission coupled with the EM57/inverter stack. A direct drive setup would be lighter and likely more efficient but I don't think it would be as enjoyable. From what it looks like there would be enough room to put the motor at least partially in the transmission tunnel since Subaru made it so large/mounted the engine far forward (a transaxle could be possible too). It's impossible to say how I will like it until the build is complete. A higher final drive ratio could help and there is also the possibility of removing gears or going to a different gear set.


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## YumYum (Jul 1, 2020)

So far I have collected a substantial amount of CAN logs for every scenario I could think of. This would be anything from locking the doors to VSC activation. The BRZ is a simple vehicle electrically, so it has been relatively easy to figure out what is going on the bus.

A problem I expected to run was with the immobilizer system. I expected this to communicate with the ECU to fetch key RFIDs. However I disconnected the ECU and the immobilizer light still functions as it should. I will have to diff the logs to be sure. However I don't think any key data is stored in the ECU from what I saw with the ECU replacement process.

With the ECU disconnected I thought it would be a good time to try out some of the functions I've isolated, like activating EPS. Everything has worked well so far. Even running a log of the car driving back to the ECU showed great results. The speedometer and traction systems were a little confused since real wheel speed was 0 but all systems responded except for the oil and alternator lights. I believe these are mechanically activated and not run through the bus but I will have to investigate.

The engine will be out once the refrigerant is captured


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## YumYum (Jul 1, 2020)

Engine is out. It was a fairly simple removal despite the lack of information online. Disconnect the harness, fuel lines, 2 ground straps, engine mounts and transmission bolts. The engine was being lifted out the third hour in but the headers were colliding with the fan shield. I finally gave in and removed the headers after trying every other solution. It was pretty easy since the studs had no rust; they looked like some special material.

Unfortunately the 12v battery had been leaking substantially and got battery acid all over the right side on the engine bay, pulling the paint off of the subframe. So before any other work can be done there will have to be some clean up and painting.

As a mock up I put my DC-DC and charger where the 12v battery used to be. They fit very well and I can use the existing mounts to fasten the two down. A more compact all in one unit would be better but this will work for now. The stock 12v will be recycled and will be substituted with a sealed motorcycle battery. Depending on the space remaining it may be able to occupy some of its old space but it will likely be relocated somewhere else.

Next I will be working on the transmission adapter and a block off plate for the starter motor hole.


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## Bratitude (Jan 23, 2020)

YumYum said:


> I have decided to share some of my project so far. I am removing the FA20 from my 1st gen Subaru BRZ and putting in an EM57 from a 1st gen Nissan leaf. The project has had a slow start so far. It has been sitting for some time while I finished up with other work. I've noticed there are few projects regarding newer vehicles, especially those with extensive CAN networks and OBD; I suppose people prefer older vehicles for their projects.
> 
> With all the increased attention around electric vehicles lately, where did the electric sports car go? With the departure of the Tesla Roadster, I would argue there hasn't been any realistically priced car in that category since. It wasn't remotely affordable for the average person but was still significantly cheaper than others like the R8 e-tron and SLS electric. This leads me to building my own using the Subaru BRZ as a base vehicle.
> 
> ...


This exact build has been done well documented here: Toyota GT86 with Nissan Leaf Motor - openinverter forum

Em57 adapter plate cad files: GitHub - angusjo/adapter-plate
also I have couplers available for the leaf motors
Wire EDM machined out of 4140 chromoly 
260$


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## brian_ (Feb 7, 2017)

Bratitude said:


> This exact build has been done well documented here: Toyota GT86 with Nissan Leaf Motor - openinverter forum


That conversion was also discussed in this forum, in Subaru conversions


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## Tremelune (Dec 8, 2009)

Cool project! Not for nothin', but it doesn't _look_ like it'd be that hard to put a Leaf motor with the reduction gear in the rear of this thing. That would save weight and space for batteries...


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## Bratitude (Jan 23, 2020)

There’s this project, whom mounted a leaf motor in the rear of a legacy subframe Log into Facebook








And in this case, I am in the early stages of designing and testing some stub shafts for the leaf gearbox, which will have 25 Subaru outer splines. so suby axles will just mate to a leaf gear box!








The reasoning behind this is I’m also machining a matching set of 930 to suby cv axle flanges. No custom axles when mounting a leaf gearbox in vw’s, Porsche’s, bmw’s, Nissan’s, etc.


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## brian_ (Feb 7, 2017)

Tremelune said:


> ... Not for nothin', but it doesn't _look_ like it'd be that hard to put a Leaf motor with the reduction gear in the rear of this thing. That would save weight and space for batteries...


It does look there's enough width between the suspension control arms to fit the entire Leaf drive unit, and it would be nice to have it all back there. On the other hand, that subframe would need to be radically altered (or entirely replaced with a custom fabrication) and even without the charger or PDU the unit would be taller, presumably going through the floor. It might make it without the inverter, but the top of this assembly is flat for a reason - it's against the floor.


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## brian_ (Feb 7, 2017)

Bratitude said:


> There’s this project, whom mounted a leaf motor in the rear of a legacy subframe Log into Facebook
> View attachment 123510


This Legacy subframe and suspension are not the same as the Impreza, but they are similar enough (as are most recent cars with a driven rear axle and multilink rear suspension) to illustrate the concept. In this case, the front of the subframe was modified - fortunately in the Legacy the trailing control arms apparently don't mount to the subframe, making that easier.


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## Bratitude (Jan 23, 2020)

dose the brz use the Impreza rear clip? I would imagine its a slightly different design.

a gen1 motor would be ideal being the inverter and motor don’t creat a seals unit together. I reckon it’s possible, if one is fabrication savy enough.

an mother note, a Lexus gs450h gearbox might be a good fit to try to maintain the original weight distribution.


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## brian_ (Feb 7, 2017)

Bratitude said:


> dose the brat use the Impreza rear clip? I would imagine its a slightly different design.


As far as I know, the BRAT was mechanically a Leone (and in body a modified Leone station wagon); it wasn't like the Golf/Rabbit pickup (Caddy) which had its own suspension. The BRAT was so long ago that it was the Leone, not the later Impreza. The Leone had a basic semi-trailing arm rear suspension.

After the BRAT was the Baja, which was a utility body variant of the Legacy/Outback.



Bratitude said:


> a gen1 motor would be ideal being the inverter and motor don’t creat a seals unit together. I reckon it’s possible, if one is fabrication savy enough.


I agree... and separating the more recent Leaf inverter from the motor has been done.



Bratitude said:


> ... a Lexus gs450h gearbox might be a good fit to try to maintain the original weight distribution.


That makes sense. 
The battery will be heavier than the engine, but if some of the battery can be in the back (replacing the fuel tank, but the shape is really awkward) perhaps a reasonable distribution is possible. In its stock form the BRZ is more front-heavy than this sort of car should be, because the engine and transmission are too far forward.


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## Bratitude (Jan 23, 2020)

brian_ said:


> As far as I know, the BRAT was mechanically a Leone (and in body a modified Leone station wagon); it wasn't like the Golf/Rabbit pickup (Caddy) which had its own suspension. The BRAT was so long ago that it was the Leone, not the later Impreza. The Leone had a basic semi-trailing arm rear suspension.
> 
> After the BRAT was the Baja, which was a utility body variant of the Legacy/Outback.
> 
> ...


Spell check got me and changed brz to brat. Yes the EA era cars where all semi Trailing arm rear suspension.
I’ve made longer/wider trailing arms for my brat.
re sealing off the phase connections on a em57 motor isn’t to hard, but a em61 would be the ideal choice.

With the gs450h route, There seems to be plenty of space underneath for modules, so between gas tank location and engine bay, I reckon a pretty slick ev sports car would result. Probably enough space for 50kw of storage, based off Phil’s leaf swapd bzr/86


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## brian_ (Feb 7, 2017)

Bratitude said:


> Spell check got me and changed brz to brat.


Ah... I wondered if you were looking for an alternate rear suspension.
Yes, the BRZ (FR-S, GT86) is essentially a pre-Global Platform Impreza (GJ/GP) in suspension, except:

the rear subframe is different to accommodate a different final drive unit (differential), and
the front suspension is tweaked quite a bit:
control arms are reversed so they extend forward instead of rearward
struts are inclined further inward to allow the springs to be lower for a lower hoodline

The rear suspension is very close but possibly not identical (depending on model year) - I checked online OEM parts diagrams and found that some components (e.g. upper control arms, lateral arms) have the same part number for a 2014 Impreza and a 2014 BRZ, while others are slightly different (e.g. knuckles, trailing arms). Some parts (e.g. lower lateral arms) are listed for the Impreza, Forester, and Crosstrek XV.


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## YumYum (Jul 1, 2020)

The BRZ was based on a shortened Legacy. You can find photos of its evolution on the internet. As for fitting the motor in the rear subframe, it may be possible but looks at it from underneath it seems like there is not enough room for it to fit. The subframe will be dropped in order to remove the tank; when that happened I can get a photo with the EM57 for comparison. 

I can say for sure I will not be using a GS450H motor combo as I already have an EM57. These other custom setups would all drop the manual transmission which is something I wanted to keep with the project. 

In terms of progress, I have been slowed by some miscellaneous issues. The CAD work for my motor coupling is in progress along with the charger and DC-DC mounts.


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## brian_ (Feb 7, 2017)

YumYum said:


> The BRZ was based on a shortened Legacy.


Or, as everyone in the automotive press reported and visual examination seems to confirm, the Impreza. All recent Subaru chassis are very similar.


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## YumYum (Jul 1, 2020)

brian_ said:


> Or, as everyone in the automotive press reported and visual examination seems to confirm, the Impreza. All recent Subaru chassis are very similar.





http://images.pistonheads.com/nimg/25437/BRZDevelopmentBoard-L.jpg



Maybe the Legacy and Impreza share parts. I don't know if they do.


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## brian_ (Feb 7, 2017)

YumYum said:


> http://images.pistonheads.com/nimg/25437/BRZDevelopmentBoard-L.jpg
> 
> 
> 
> Maybe the Legacy and Impreza share parts. I don't know if they do.


Interesting... although development mules routinely share no parts or design details at all with the final product. 

All recent Subaru's are pretty closely related, so there are undoubtedly some parts in common between any two models. I just checked an online parts catalog, and indeed 2014 Impreza and Legacy rear suspensions are nearly identical, although the subframes are visibly different. In the same diagrams, the BRZ subframe looks more like the Impreza part than the Legacy part.

The BRZ is close enough to the Impreza that when it came out I went to a Subaru dealer and opened the hoods on each model, and found that even a substantial section of the firewall, with the attached brake master cylinder and other components, was identical. To be fair, I didn't do the same with a Legacy.

The entire catalog of Subaru components of the era are possible sources for the BRZ, and there will be differences (in addition to the obviously unrelated transmission) with any model.


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## YumYum (Jul 1, 2020)

It has been a while since I gave an update. Not to worry, the project is still going. Parts are being machined right now


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## YumYum (Jul 1, 2020)

I have looked through ISO 4156 and didn't find a suitable match for the EM57 spline. I will be referencing JIS automotive specs to see if that is what Nissan used


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