# Subaru conversions



## scubascooby (Jun 21, 2021)

I have been looking around for info on Subaru conversions. There was a great site where a Impreza had been converted but it has gone.

I just found this GT86 conversion:








Toyota GT86 with Nissan Leaf Motor (Update 11/2022: 160Kw) - openinverter forum



It's interesting because it is a modern car, not a classic, and they have a canbus solution.


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## brian_ (Feb 7, 2017)

scubascooby said:


> I just found this GT86 conversion:
> 
> 
> 
> ...


I think it's unfortunate that in this conversion the motor is placed so far forward that it is just as bad as the original engine, which is way too far forward for this type of car (the one notable design issue with the BRZ/GT86). Given that the Leaf motor shouldn't need the large 6-speed transmission, this seems like a missed opportunity.

In a post on Jan 21, 2020, the builder shows how he has determined that the transmission should be in third gear (a 1.541:1 ratio). If it is to be just left in 3rd, the huge transmission is mostly wasted - a compact and lighter fixed-ratio gearbox would be preferable. There were later references to shifting, so the transmission is being used effectively at least at times.

I'll also note that in that OpenInverter thread, the builder uses the term "battery" where "module" would be more in line with normal practice.

Near the beginning (Nov 04, 2019) the builder provided corner weights, but I couldn't find any follow-up so we unfortunately don't know how the conversion changed the vehicle mass or mass distribution.

Despite these detail reservations that may be of interest to anyone doing a similar conversion, this GT86 is a nice project.


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## scubascooby (Jun 21, 2021)

The boxer engine is short and low but wide.

I would be more concerned if the conversion raised the CoG higher than the boxer.


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## scubascooby (Jun 21, 2021)

The Leaf motor looks like a good replacement for the Subaru 2.0 td.

Power of 148 bhp is identical while 236 lbft is down on 258 lbft but not badly and it is more than the 2.5 petrol.


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## brian_ (Feb 7, 2017)

scubascooby said:


> The boxer engine is short and low but wide.
> 
> I would be more concerned if the conversion raised the CoG higher than the boxer.


The motor is similarly short, much narrower, and just as low. Of course motors often have a controller and other components sitting on top of them, while boxer engines have intake and other accessories sitting on top of them.

In this conversion, the motor shaft takes the place of the engine shaft, so the motor and engine are at the same height. There's no problem with this, but it's a missed opportunity: the motor doesn't have a sump, so it could sit lower and maintain ground clearance if it were not constrained by the stock transmission position and whatever structure runs under it.

In a normal Subaru, the engine is very high, to place the transmission input shaft over the differential. With the engine in front of the axle there's no way to put a steering rack up there, so it runs under the transmission. The BRZ/86 adaptation keep the rack position (for the same reason, even with the engine shifted back somewhat) and that forces the transmission to stay high and keeps the engine and transmission from going further back. The starter motor also prevents the engine from being further back, as it would run into the firewall. After the conversion due to the differences between the boxer engine and and electric motor, the vehicle could have a desirable front-steer configuration and the motor and transmission substantially further back... but it's stuck with the compromises caused by the boxer. A conversion of another Subaru, again using the original transmission, would need to keep the transmission in the same place to line up with the front axle, so these placement issues are unique to the BRZ/86.

The big centre of mass (CofG) issue is usually the battery. In this case, most of the modules are quite low (in the trunk, in the fuel tank space, and flanking the motor), although some are stacked higher in the engine compartment. That's a lot better than many conversions. The part which is unfortunate about the mass is that most of the battery mass is too close to the ends, rather than within the wheelbase. That's the result of the small car not having any other space, and the configuration of the motor taking the prime underhood space. At least it's much better than stacks of modules (or lead-acid batteries!) stacked over the motor and all the way to the nose, as has been done with other conversions of other vehicles.


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## JSHarvey1961 (Nov 1, 2014)

brian_ said:


> I think it's unfortunate that in this conversion the motor is placed so far forward that it is just as bad as the original engine, which is way too far forward for this type of car (the one notable design issue with the BRZ/GT86). Given that the Leaf motor shouldn't need the large 6-speed transmission, this seems like a missed opportunity.
> 
> In a post on Jan 21, 2020, the builder shows how he has determined that the transmission should be in third gear (a 1.541:1 ratio). If it is to be just left in 3rd, the huge transmission is mostly wasted - a compact and lighter fixed-ratio gearbox would be preferable. There were later references to shifting, so the transmission is being used effectively at least at times.
> 
> ...


It may be the owner wanted to keep the AWD aspect of the Subaru - that is a defining feature and often the reason someone buys a Subaru in the first place. To do that they have to keep the whole transmission/AWD unit as it is a fully integrated "part".


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## brian_ (Feb 7, 2017)

JSHarvey1961 said:


> It may be the owner wanted to keep the AWD aspect of the Subaru - that is a defining feature and often the reason someone buys a Subaru in the first place. To do that they have to keep the whole transmission/AWD unit as it is a fully integrated "part".


With another Subaru model that would make sense, but this is a Toyota GT86 (a.k.a. Subaru BRZ, or Scion FR-S)... which is a rear-wheel-drive-only car. AWD is not available for this model.


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## scubascooby (Jun 21, 2021)

Retaining the gearbox and minimising the mechanical changes may have made it easier to get it legally approved in Germany.


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## scubascooby (Jun 21, 2021)

I'm not sure which section to post this question in so I'm asking it here.

When they refer to the Leaf "motor stack" which items are included ?


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## Electric Land Cruiser (Dec 30, 2020)

scubascooby said:


> I'm not sure which section to post this question in so I'm asking it here.
> 
> When they refer to the Leaf "motor stack" which items are included ?


PDM+chargers (top)
Inverter (middle)
Motor+gearbox (bottom)


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## scubascooby (Jun 21, 2021)

Forgive my ignorance.

So does that just leave the battery and the BMS as the remaining parts needed from a donor car ?


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## Electric Land Cruiser (Dec 30, 2020)

scubascooby said:


> Forgive my ignorance.
> 
> So does that just leave the battery and the BMS as the remaining parts needed from a donor car ?


Correct, and the BMS is inside the battery box itself. If you have those components, the wiring harness, and a Resolve-EV controller you have everything needed to make your own EV.


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## scubascooby (Jun 21, 2021)

Thanks.

I'm trying to get an idea of availability and cost here in Britain or Europe (if necessary).

I wasn't aware of the Resolve EV controller. 

More research needed.


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## scubascooby (Jun 21, 2021)

EV Breakers in N Ireland has a 160kW motor stack for £1700. It's the first one I've seen.

I gather there is better availability in Norway.


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## scubascooby (Jun 21, 2021)

I'm trying to figure out extent of the Resolve EV control functions EV conversion kit with Nissan Leaf parts (used) | Resolve-EV , I assume it is just the battery and motor side and that the CANbus controller, used in the GT86 conversion, is still needed.

I have this on my shopping list:

Arduino based replacement ECU for CAN-communication from Geraldjustprojects.com


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## 26979 (May 19, 2012)

JSHarvey1961 said:


> It may be the owner wanted to keep the AWD aspect of the Subaru - that is a defining feature and often the reason someone buys a Subaru in the first place. To do that they have to keep the whole transmission/AWD unit as it is a fully integrated "part".


I'm attempting to do just that right now


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## tdubbshi (24 d ago)

26979 said:


> I'm attempting to do just that right now


how are you keeping the AWD? i thought of running double leaf or hyper 9 but stuck on what to do to keep them 50-50 split


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## brian_ (Feb 7, 2017)

tdubbshi said:


> how are you keeping the AWD? i thought of running double leaf or hyper 9 but stuck on what to do to keep them 50-50 split


A conversion that retains the original transaxle and everything beyond it (shafts and rear final drive unit) keeps the same front-rear torque split. That split may not be 50:50, depending on the specific AWD system.


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## Tomdb (Jan 28, 2013)

What year of Subaru are you looking at? 2001-2017 build years cannot get reclassified on fuel type/tax class in the UK.

Also a Subaru, again depending on year will have a bunch of electronics you will need to keep happy for the various systems to keep operating.


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## remy_martian (Feb 4, 2019)

Am curious why the can't be reclassified if they've been deICEd?


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## Tomdb (Jan 28, 2013)

remy_martian said:


> Am curious why the can't be reclassified if they've been deICEd?


Bureaucracy, they way one entity responsible for the database interprets legislation.


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## scubascooby (Jun 21, 2021)

My thought is that it's a hang over in the regulations from the Euro emissions era that doesn't allow for EV conversions.

They is a long discussion on openinverter.

I suppose there is a very slim possibility that they might revise the rules but I wouldn't hold my breath.


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## tdubbshi (24 d ago)

brian_ said:


> A conversion that retains the original transaxle and everything beyond it (shafts and rear final drive unit) keeps the same front-rear torque split. That split may not be 50:50, depending on the specific AWD system.


mine is 5 speed so i think i should be able to keep the trans and everything else as long as an get an adapter to mate between the new motor and trans based on a shops reply


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## brian_ (Feb 7, 2017)

tdubbshi said:


> mine is 5 speed so i think i should be able to keep the trans and everything else as long as an get an adapter to mate between the new motor and trans based on a shops reply


Fortunately, Subaru 5-speed manuals typically have a centre differential, so with none of the electronic controls working you still have AWD, with a 50:50 torque split (and 50:50 is good for a moderately front-heavy car).


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## tdubbshi (24 d ago)

brian_ said:


> Fortunately, Subaru 5-speed manuals typically have a centre differential, so with none of the electronic controls working you still have AWD, with a 50:50 torque split (and 50:50 is good for a moderately front-heavy car).


Something else to note what is everyone using for the gear ratios? an adapter and reduction? I saw there was another with a evo 8 asking not sure if he ever got his answer though


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