# The Lexus GS450h motor



## MattsAwesomeStuff (Aug 10, 2017)

As I recall, Damien knew of another guy who reverse engineered it, but he was unwilling to share any of the details or knowledge gained from that.

I might be confused on all his projects but I think the Bexus right now is unmodified. You (or I) might be thinking of another vehicle he's been working on using the gearbox, that he bought cheap, sold the motor for more than he paid for the vehicle, and did a full conversion.

Far as I know Damien and Kevin bought the Bexus Lexus it last month in England for 500eu (dead hybrid battery) and drove it back to Ireland, and just got it road-legal in Ireland (as a factory Hybrid).

The Bexus is being saved for one of the classes at Kevin's shop that Damien runs monthly (it's an advanced class scheduled for the summer I believe). They are going to do a 1 weekend conversion class and use it as the demo.

The goal is basically, engine out, more batteries in, and de-hybridizing the 10,000,000 dead-ish hybrid vehicles in the world.

The GS540H has seen a lot of interest lately, within the last year, and, as things take time, I'd expect to see a lot of conversions get finished this year using them. The trend seems to be Prius's for FWD conversions and Lexus's for RWD and higher power conversions.


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## kodachrome (Apr 27, 2017)

Isn’t this all that you need?


https://www.evbmw.com/index.php/evb...sted-boards/gs450h-vcm-fully-built-and-tested


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## DrGee (Aug 22, 2018)

MattsAwesomeStuff said:


> The GS540H has seen a lot of interest lately, within the last year, and, as things take time, I'd expect to see a lot of conversions get finished this year using them. The trend seems to be Prius's for FWD conversions and Lexus's for RWD and higher power conversions.


I think the Prius for FWD & Lexus gs450h for RWD are excellent choices. It will be interesting to see if de-icing hybrids becomes a trend... 
Thanks for the info Matt, always glad to hear from you!


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## DrGee (Aug 22, 2018)

kodachrome said:


> Isn’t this all that you need?
> 
> 
> https://www.evbmw.com/index.php/evb...sted-boards/gs450h-vcm-fully-built-and-tested


That plus the motor/transmission and the donor car and battery pack and of course, the inverter - but yes, that's the one.


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## Hollie Maea (Dec 9, 2009)

Another forumer here did a very well done conversion with this transmission. His thread is worth a read. He sold it a year or so ago. I was tempted...

https://www.diyelectriccar.com/forums/showthread.php/bmw-330ci-conversion-142946.html


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## DrGee (Aug 22, 2018)

I checked out that thread - fantastic details! I'd no idea this kind of thing had been going as far back 2015.


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## cinephile (Feb 27, 2015)

I've been following Damien Maguire's many videos on Youtube for the last couple of years since he was working on his EV BMW 840 coupe.

Since, I've been looking into many motor and controller options for a mere 200hp, 250hp or 300hp without blowing any many transmission gears to smithereens and without spending $20k on the swap motor alone even before the other required hardware and batteries.

His continued progress on the GS450h transmission has intrigued me with its nearly 250hp potential once the input shaft is locked and the controller is sufficiently tricked into running the MG1 and MG2 motors simultaneously.

I've never heard him talk about the torque but I assume in this configuration it would need to go onto a dyno to properly measure the true output from MG1 and MG2 combined. I could be wrong but I think Toyota might only have officially stated the MG2 (output) motor torque and power while the MG1 was not considered by Toyota engineers to be a main drive power source.

Still... as it stands it's looking like a great package no matter what.

I've just completed an SC300 5-speed turbo project and now I'm eyeballing this to go into an IS300 (sedan or wagon) or FR-S. I'd prefer manual gearing to be retained but as a complete package this is hard to beat in a commuter EV that could be used every day in traffic.

After doing a little research into the Lexus GS450h it seems to have come with a 3.769:1 rear differential as standard and with its unique transmission will go to 155mph.

Therefore any RWD donor vehicle which can get a 3.7x:1 ratio rear axle into it or close to that (3.9x:1, etc.) should retain the same top end characteristics gearing-wise.

Even with the a pack voltage lower than Damien's stated 400v in his "Bexus" (or was it 450v?) I still think it would cover all bases for moderately powered compact RWD and even some large RWD conversions.

In really lightweight RWD donor chassis (FR-S, Miata, small 60's-80's RWD cars) it would be an amazing power and torque output combination for the money.


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## drother (Sep 11, 2014)

MG2 is only rated to spin 10,230 rpm, and high gear ratio is 1.9:1. Keep this in mind, as your driveshaft speed will be limited to 5,384 rpm. With a pretty tall 28” tire, the stated 3.769 rear gear, thats ~119mph not 155. 

If you lock the input shaft for MG1, its even lower. There is some debate whether its 10,000 rpm or 14,000 rpm. If its 14,000 rpm MG1 would be limited to ~114mph. If you weld up the planetary gears to the carrier, you wouldn’t be limited like you would if you lock the input shaft, but lower torque.


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## MattsAwesomeStuff (Aug 10, 2017)

DrGee - Oops. I was wrong, you were right.

The "Bexus" Lexus conversion is nearing completion. That's the one he's been working on.

The "Lexi" Lexus conversion is the one I was talking about, that's being saved as-is until the weekend conversion class in August.

Here's Damien pointing out both cars side by side:

https://www.youtube.com/watch?v=fg-BKxNlwjg&t=52

Damned things are both grey (which is also different than his BMW "Grey Goose").


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## kodachrome (Apr 27, 2017)

DrGee said:


> That plus the motor/transmission and the donor car and battery pack and of course, the inverter - but yes, that's the one.


I was really replying to MattsAwesomeStuff as from his reply I was getting confused as to what was working or not!
Im also very interested in these developments, after literally years looking at options, this is ticking the most boxes on ease, price and performance.. I think, the required skill set on this stuff is so broad!

I have a 1983 BMW 5 series (E28) that would be a fantastic platform for this.


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## MattsAwesomeStuff (Aug 10, 2017)

DrGee said:


> It will be interesting to see if de-icing hybrids becomes a trend.


There are 8+ classes scheduled for the next year, 10 participants each, $1000/per person. Plus they're in Ireland and almost all participants are flying in from around the world.

Previous participants have already started manufacturing adapters to lock the gearboxes so they can be ran as EVs.

I think it's certainly the new meta for EV conversion parts, why buy a $200 forklift motor and then spend $1000 on a controller when you can buy a $1000 pre-engineered drivetrain with matching inverter?

But just keeping the hybrids as-is seems to be a popular idea too.



cinephile said:


> I've never heard him talk about the torque but I assume in this configuration it would need to go onto a dyno to properly measure the true output from MG1 and MG2 combined. I could be wrong but I think Toyota might only have officially stated the MG2 (output) motor torque and power while the MG1 was not considered by Toyota engineers to be a main drive power source.


MG2 is the drive motor.

MG1 is to start the engine and to do regenerative braking.

However, MG1 is usually ~2/3 the size of MG2, and if you axe the engine, no reason you can't drive both motors to propel the car down the road.



drother said:


> There is some debate whether its 10,000 rpm or 14,000 rpm.


If it's like the Prius, it'll depend on year.

1st gen is like 6500.
2nd gen is 10,000.
3rd gen is 13,500.
4th gen is 17,000.

Ditto for whether you can lock the input shaft or have to weld the planetaries. In the Prius 3rd gen and onward, there's a second set of planetaries for MG2 and you can just lock the input shaft.

In any case, no one needs to be or ever will be travelling 156mph in a goddamn Lexus. Or 114mph. Moot point.

...

In other news, there's also the Toyota AWD models, which have a cute little ~100 lb rear end that has a supplementary motor in it. Probably good enough for light use on light old car conversions but not enough for anything sporty.


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## MattsAwesomeStuff (Aug 10, 2017)

kodachrome said:


> I was really replying to MattsAwesomeStuff as from his reply I was getting confused as to what was working or not!


I was ambiguous in my reply.

DrGee asked if anyone other than Damien had used the GS450h.

I said that Damien had mentioned someone else who had, but he (unambiguously, the other guy, not Damien) wouldn't share how.

Damien does share how, and, made drop-in boards to accomplish it.

So to answer your question, yes, that's all you need control-wise.


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## kodachrome (Apr 27, 2017)

MattsAwesomeStuff said:


> So to answer your question, yes, that's all you need control-wise.


This makes me happy, thanks for the clarrification!


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## brian_ (Feb 7, 2017)

MattsAwesomeStuff said:


> MG2 is the drive motor.
> 
> MG1 is to start the engine and to do regenerative braking.


No, that would be using MG1 like a mild hybrid system, and MG2 like an unrelated parallel hybrid on the same vehicle, and ignoring the critical power-split planetary gear set.

The power-split planetary gear set means that the speed of MG1, combined with road speed, determines the engine speed; MG1 is run at whatever speed is required and its power is a result of that speed and the torque required to balance engine output torque.
The operation of MG1 can produce or consume power; whatever it does, MG2 complements it in steady-state operation (plus or minus whatever the control system decides to pull from or return to the battery). So if MG1 is generating, MG2 is motoring, and the flow of power from the engine to the wheels is split between a mechanical path and an electrical path. In a range of road speed and engine speed combinations the power is actually from MG2 to MG1, so power is recirculating (mechanically from engine to wheels with some looping back from MG2 to MG1).

If the engine is idling then MG1 is just spinning with minimal torque, which means that for normal regenerative braking it is all done by MG2.



MattsAwesomeStuff said:


> However, MG1 is usually ~2/3 the size of MG2, and if you axe the engine, no reason you can't drive both motors to propel the car down the road.


I agree with that part: a simplistic EV operation which wastes one motor, much of the transaxle, and one section of the controller/inverter would be to just use MG2, and that would work (and is how the hybrid works in EV mode, because MG1 can't be used without operating the engine). A better EV operation would use MG1 as well, logically by locking the power split gearset so that MG1 and MG2 speeds are synchronized; my understanding is that this is the conclusion already reached by many builders as discussed earlier in the thread.

The relative sizes of MG1 and MG2 in power-split hybrids depends on the modes supported (Toyota uses only input power-split, but GM and others have used additional modes including output power-split, and dual split) and gear ratios between components (the extra multi-ratio transmission between MG2 and the wheels of some later Toyota hybrids - the GS and LS variants - allows more optimal operation of both motor-generators, but to different extents). MG1 is usually substantially smaller, but it's still a significant motor.

If you want a challenge, try to follow all of the modes of a Gen 2 Volt (the 5ET40 transaxle) or the old 2-mode transmission from GM pickups and SUVs (the 2ML70) and similar transmissions from BMW and Chrysler.


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## brian_ (Feb 7, 2017)

MattsAwesomeStuff said:


> The GS540H has seen a lot of interest lately...


That's just a typo, and you meant GS 450h, right?


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## MattsAwesomeStuff (Aug 10, 2017)

> That's just a typo, and you meant GS 450h, right?


Oops. Yes.


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## KiwiPete (Aug 2, 2019)

Can anyone point me to a dimensioned drawing of the GS450H? I am still researching power plants for my conversion https://www.diyelectriccar.com/foru...en-traction-avant-11bl-conversion-202325.html and this would make a really interesting option.

I'm almost certain that its too long - but I can't find any documentation on it. My Google-fu is normally pretty good but I'm striking out.

Pete


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## KiwiPete (Aug 2, 2019)

.... GS450H transmission. TBC.


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## KiwiPete (Aug 2, 2019)

I found the following buried on an OpenInverter forum post. I'll add it here in case someone else is searching too.


Overall height (oil pan to top of bellhousing) is 39cm. Bell housing is full height, i.e. 39cm diameter, when the transmission is sitting on its oil pan (as it is on my bench), the bellhousing still just about touches the bench.

Widest point is 40cm, includes a bump for a starter motor which I don't believe the GS450h even has. Likely leftover to mate with the 2GR engine.

Overall length including tailshaft, output flange, and pilot shaft, is 82cm.

Transmission is tapered quite heavily, the width and height is closer to 25cm after the bellhousing, but hard to gauge due to various outcropping parts (motor cables, oil pump, PRNDL selector, etc)

Weight feels like in excess of 100kg, I'd say closer to 120-150kg.


Source:
https://openinverter.org/forum/viewtopic.php?f=14&t=205&p=3542&hilit=gs450H#p3542


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## drother (Sep 11, 2014)

FYI Im guessing we can assume the rev limit of MG1 is 14,000 rpm. If the input is locked, -14,000 MG1 RPM = 10,230 MG2 RPM in high gear (it’s rev limit).


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## brian_ (Feb 7, 2017)

KiwiPete said:


> Can anyone point me to a dimensioned drawing of the GS450H?


The transmission in the GS 450h is the L110, built by Aisin. The L110F is the same thing, plus a transfer case on the end for AWD, used in the LS hybrid. The L210 is a variation used in the IS 300h, RC 300h, GS 300h (it may be just the L110 but missing the two-speed output gearing; it may be a longitudinal variation of one of the transverse hybrid transmissions). The LC 500h and coming LS 500h use the L310, which is generally similar to the L110, but with a four-speed planetary mechanical transmission on the output (rather than the two-speed of the L110).

Unfortunately, I don't think that will help you find a dimensioned drawing, since there's not much reason for anyone to publish that to the public, other than another enthusiast sharing information. What you have already found and shared is probably about all you'll get.


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## brian_ (Feb 7, 2017)

KiwiPete said:


> I found the following buried on an OpenInverter forum post. I'll add it here in case someone else is searching too.
> 
> 
> 
> ...


The comment about the starter motor bump is a hint at the reason for much of the shape: it has to bolt to Toyota engines just as a conventional transmission does. That's why it has a flared front (bell housing section), even though there is no clutch or torque converter in there. Depending on where the transmission is to be mounted as an electric-only drive unit, I would consider checking if some housing trimming can be done to remove bulk around the front.


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## retrEVnoc (Mar 23, 2019)

I’m also pretty interested in grabbing one of these drivetrains next time one appears at the junkyard near me. Or maybe finding a cheap GS450h on Craigslist and just converting it!

Big question! Is the GS450h really the only car with this drivetrain?


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## drother (Sep 11, 2014)

retrEVnoc said:


> I’m also pretty interested in grabbing one of these drivetrains next time one appears at the junkyard near me. Or maybe finding a cheap GS450h on Craigslist and just converting it!
> 
> Big question! Is the GS450h really the only car with this drivetrain?


The Lexus LS600h has an AWD version of it. Although they seem to be more rare.


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## brian_ (Feb 7, 2017)

retrEVnoc said:


> Is the GS450h really the only car with this drivetrain?


That depends on how specific you mean when you say "this drivetrain"...


brian_ said:


> The transmission in the GS 450h is the L110, built by Aisin. The L110F is the same thing, plus a transfer case on the end for AWD, used in the LS hybrid. The L210 is a variation used in the IS 300h, RC 300h, GS 300h (it may be just the L110 but missing the two-speed output gearing; it may be a longitudinal variation of one of the transverse hybrid transmissions). The LC 500h and coming LS 500h use the L310, which is generally similar to the L110, but with a four-speed planetary mechanical transmission on the output (rather than the two-speed of the L110).


Yes, the GS 450h appears the only model with exactly the L110. All of the other variations listed above would be usable, but modifications done by others might not directly apply.


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## cinephile (Feb 27, 2015)

MattsAwesomeStuff said:


> In any case, no one needs to be or ever will be travelling 156mph in a goddamn Lexus. Or 114mph. Moot point.


No offense but you must not be very familiar with the very popular community that modifies Lexus SC300's and GS300's with turbocharged extremely high horsepower (650whp-900whp++) Toyota inline-six engines and who do exactly that up through 160mph or so in some of the crazier examples. The older SC chassis and suspension is 97% the same as a 90's Toyota Supra chassis and suspension which should explain why this is a thing. This has been and still is done in, as you put it "a goddamn Lexus".

I am *not* one who will go nearly that far with my own Lexus SC300 but it is geared for a maximum of 183mph at engine redline even though the speedo only goes to 160mph at which point the mere 350hp (turbocharged) that the car has probably would not be enough to go much faster than 150-155 or so. Unless aero or engine power were tweaked very significantly.

I'm not going to do that and I am certainly NOT advocating everyone travel at 150mph. I'm just saying that those particular turbocharged Lexus RWD cars (IS, SC, GS) are quite capable of those Autobahn level speeds and are hardly out of breath at only 114mph. 

That covers the "or ever will be" part. The "No one needs to" part... I'm not going to argue with that as it's quite an obvious point as far as public roads are concerned.

I'd just prefer to replicate the original max speed spec of the chassis (or at least what it's speedo maxes out at) with an EV conversion of that chassis. Brand new high end ICE cars and high end EV cars alike offer very high top speeds that should never be used outside of the German unrestricted Autobahn or a racetrack. And yet people still buy them for some reason.


With this modified Lexus hybrid transmission the objective obviously isn't to match ridiculously high modified turbo ICE power levels. I'm very interested in it for either an IS300 or perhaps converting my SC. 250-270hp from this dual motor hybrid transmission would be quite fine given how different the power delivery is from an ICE.

Since it would take up far less space than a Toyota inline six engine and transmission there should probably be enough room to hook it up to a 2-speed transfer case such as from Torque Trends to solve the lack of gearing.

Barring that, instead of the 3.769:1 rear end ratio I mentioned a commonly available (for the 90's Lexus SC and GS vehicles) 3.26:1 rear end ratio would offer a slight improvement in the top speed department. Have to check to see if a similar 3.2x rear end ratio is out there for the IS300 chassis.

Now if this same modified GS450h gearbox-turned-drive-unit were to be dropped into an early 90's Mazda Miata which had an original top speed of 116mph then it would actually be a near perfect match if a 3.7-ish gear ratio for that car's differential exists. In that much lighter little chassis it would be quite a ridiculous power to weight ratio.


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## brian_ (Feb 7, 2017)

cinephile said:


> Since it would take up far less space than a Toyota inline six engine and transmission there should probably be enough room to hook it up to a 2-speed transfer case such as from Torque Trends to solve the lack of gearing.


A two-speed gearbox can be an effective way to manage the wide range of operating speeds required of a fast car, and the ev-TorqueBox from Torque Trends is a suitable reduction box... but it is a single-speed product - it does not shift between two ratios. Within the Lexus range of hybrid transmissions, the range of speeds would be best accommodated by any of the models with internal output gearing (2 ratios in the L110; 4 ratios in the L310).


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## RobbertJanzen (Mar 24, 2020)

Does somebody know what the pipe is coming from the oil pump? it looks like a sort of Vacuum hose, Does this needs to be connected?


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## buzz86us (Apr 9, 2020)

wow assuming i could figure this out this might be the perfect thing for a Safari van conversion since i can't find one that uses manual... I haven't the foggiest idea what that jumble of parts he is using on the E65 are though. Damien Maguire if you could let me know that'd be awesome


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## MattsAwesomeStuff (Aug 10, 2017)

Damien is definitely too busy to respond to individual project questions, he's solving big problems. He's said as much. He doesn't even have time to answer questions about people using his own hardware, if it can be avoided. And he's almost never here anymore (he hangs out on Open Inverter).

It's not rocket science. You take the drivetrain out of the lexus and you put it into your donor vehicle.

A Safari might be a poor choice because it's built vertically, with the engine more accessible from inside the cab through the doghouse than through the engine bay.

Also, a Safari is going to use like 1000 watt-hours per mile. The couple I've seen done reported about that kind of power draw. It's a 7 foot tall brick moving through the air.

That said, I don't know what would be a better choice. Safaris are a weird form factor to have to fit and engine and trans into and still be RWD (some are AWD).


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## buzz86us (Apr 9, 2020)

MattsAwesomeStuff said:


> Damien is definitely too busy to respond to individual project questions, he's solving big problems. He's said as much. He doesn't even have time to answer questions about people using his own hardware, if it can be avoided. And he's almost never here anymore (he hangs out on Open Inverter).
> 
> It's not rocket science. You take the drivetrain out of the lexus and you put it into your donor vehicle.
> 
> ...


okay looks like i'd be better off with a small truck.. I just want to build a small camper, I was just wondering has anybody used the Tahoe hybrid transmission? Seems like a similar part. i'm trying to decide if using the 450H hybrid transmission is worth it since it seems to be oil cooled.


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## Eric (Sep 9, 2012)

Just found out about his post yesterday and spend last night watching al Damien's video's on youtube about this transmission/motor. Read everything on OpenInvertor forum and almost hit the 'buy it now' button on Ebay for one of these transmissions.
All looks very easy, buy transmission and inverter, buy one of Damien's boards bolt it all together and there you go 

But decided to spend a good night of sleep on it.

Needed:
Transmission with everything attached to it, 
cables/wiring loom
oil pomp and oil pump controller, 
shifting stuff, 
rear flange, 
matching inverter, 
Damien's controller board, 
and what else?


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## MattsAwesomeStuff (Aug 10, 2017)

Eric said:


> and what else?


Johannes' Olimex wifi ESP8266, so you can program the control board.


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## Eric (Sep 9, 2012)

Why do i need to program it? Isn't Damiens board pre-programmed?


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## MattsAwesomeStuff (Aug 10, 2017)

Eric said:


> Why do i need to program it? Isn't Damiens board pre-programmed?


You'll want to tune it to your particular motor.

To do that, you have to connect to the brains somehow. To do that, wifi is easiest.

I'm not sure if Damien includes the Olimex Wifi board with it or not. The product page doesn't say.


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## Eric (Sep 9, 2012)

So the Lexus inverters and the Lexus transmissions are not interchangeable? I thought i had read everything about them but i must have missed that. Let's dive into that.


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## MattsAwesomeStuff (Aug 10, 2017)

Eric said:


> So the Lexus inverters and the Lexus transmissions are not interchangeable? I thought i had read everything about them but i must have missed that. Let's dive into that.


Err, no.

There is no one correct setting for your inverter.

Damien's logic board does not simply replace the original, it interfaces directly with the inverter.

Johannes' Open Inverter software has dozens of motor parameters that you can tweak and change to get different performance out of your motor. Further, you can use the data it pulls from the inverter to configure CAN components, screens, etc.

The Open Inverter software is updated and has features added to it several times a year.

The vehicle you put the motor into may change how you want the motor to perform.

So it's not the situation where you order parts, put them together, and then it stays that way forever.

Plus, if there's ever glitches or bugs, you'll need a way to reflash firmware or update things.

The whole point of the Open Inverter software is that it can work with any motor you give it to. The whole point of Damien building the logic board is so that that inverter can power any motor you plug into it, not just a Lexus transaxle.


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## Eric (Sep 9, 2012)

Well i must have misunderstood the whole thing 

I thought the board Damien makes was to get the gs450h gearbox to work with the gs450h inverter without the rest of the car around it.
But as you explain it the board is to use the gs450h inverter and use any motor you want.


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## MattsAwesomeStuff (Aug 10, 2017)

Eric said:


> I thought the board Damien makes was to get the gs450h gearbox to work with the gs450h inverter without the rest of the car around it.


In the "every square is a rectangle" paradigm, yes.

His board lets you use the GS450H inverter to drive the GS450h transaxle without having the rest of the car.

... or any other motor.

A motor is agnostic as to what's driving it. Voltage and waveform and it responds accordingly.


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## brian_ (Feb 7, 2017)

Eric said:


> I thought the board Damien makes was to get the gs450h gearbox to work with the gs450h inverter without the rest of the car around it.


Yes, like other replacement controllers for OEM controller/inverter assemblies.



Eric said:


> But as you explain it the board is to use the gs450h inverter and use any motor you want.


While the GS450h inverter could be used with any synchronous AC motor, no one is likely to do that. The reason for using the inverter from a GS450h is that it comes with the motors of a GS450h, is packaged to work with the GS450h transmission, and is electrically suitable for the GS450h.



MattsAwesomeStuff said:


> His board lets you use the GS450H inverter to drive the GS450h transaxle without having the rest of the car.


That's certainly the purpose. 



MattsAwesomeStuff said:


> ... or any other motor.
> 
> A motor is agnostic as to what's driving it. Voltage and waveform and it responds accordingly.


While that's possible, to be viable the encoder on the motor must be compatible with the controller's inputs, the voltage, current, and frequency ranges must all be compatible, and all of the tuning parameters must be appropriate to the motor. I'm not sure why anyone would go to the effort of working out this combination for anything but the inverter which the OEM provides with the motor.


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## MattsAwesomeStuff (Aug 10, 2017)

brian_ said:


> While that's possible, to be viable the encoder on the motor must be compatible with the controller's inputs, the voltage, current, and frequency ranges must all be compatible, and all of the tuning parameters must be appropriate to the motor.


Motors aren't that picky.

That's one of the things Damien nags about, that people think you have to have this and that and everything matching. No you don't. Feed it some voltage and it'll be fine. Everything is in roughly the correct range regardless of motor. Control-wise it just takes some tweaking but power-wise it's agnostic.

And there's lots of people using mismatched inverters and drivetrains. More than I've seen used matched one.


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## mdrobnak (Mar 19, 2020)

MattsAwesomeStuff said:


> Motors aren't that picky.
> 
> That's one of the things Damien nags about, that people think you have to have this and that and everything matching. No you don't. Feed it some voltage and it'll be fine. Everything is in roughly the correct range regardless of motor. Control-wise it just takes some tweaking but power-wise it's agnostic.
> 
> And there's lots of people using mismatched inverters and drivetrains. More than I've seen used matched one.


In the case of open inverter in general (or any configurable system) - you're correct. However with respect to the 450h setup, the parameters for sync offset, etc, are not available to you as _the inverter is unmodified_. It is being given the serial commands to drive the 450h transmission. Damien's controller is taking place of the Hybrid Vehicle control unit. I wouldn't consider the 450h inverter to be a general purpose inverter. 

For that, the Prius 3rd gen stuff is better.

-Matt


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## MattsAwesomeStuff (Aug 10, 2017)

> However with respect to the 450h setup, the parameters for sync offset, etc, are not available to you as the inverter is unmodified. It is being given the serial commands to drive the 450h transmission. Damien's controller is taking place of the Hybrid Vehicle control unit. I wouldn't consider the 450h inverter to be a general purpose inverter.


Hmm.

To be honest I haven't looked much at it, as it was the fancier more expensive higher power way to go. I presumed the reverse engineering took a similar path.

On the Prius boards, you yank out their logic board and plug in Damien's in the same place. You replace the brain inside it. It's a hardware replacement of the Prius brain.

What then are the 450H boards? A hardware replacement for the ECU that sends software commands that tell the 450H inverter's brains to operate as normal, but just as the ECU would've instead?


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## mdrobnak (Mar 19, 2020)

MattsAwesomeStuff said:


> Hmm.
> 
> To be honest I haven't looked much at it, as it was the fancier more expensive higher power way to go. I presumed the reverse engineering took a similar path.
> 
> ...


Exactly. The Prius board you have complete control over the hardware. On the 450h it replaces the stock ECU, yes.

-Matt


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## MattsAwesomeStuff (Aug 10, 2017)

I should've known the answer to this, as I've built one...

The Prius Gen 3 inverter has a logic board inside it that can be replaced with a custom one.

The Prius Gen 2 inverter just has a 40-pin connector and a cable that runs to, I dunno, some ECU or some inverter brains or I'm not sure what. But the replacement board is very, very simple. There's more complexity in what accessory wires you need to connect to it (throttle pedal, brake signal, etc) than there is that connect to further inverter guts. 3 drive signals (1 for each phase), 2 wires to tell it not to shut down, +-12vdc, and a pin so it knows the capacitor voltage. That's it.

There's clearly some brains below the Gen2, because it still has all kinds of intelligence in order to not let you do stupid things, turn phases on at the same time, overvolt, over current, overheat, etc. But that must be deeper in the bowels. You tell the phases what to do and it otherwise obeys.

The GS450H I'm not sure about. Is it like the Prius Gen2, replacing what comes in from the wiring harness, or is it fancier than that?


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## John_G (Jun 6, 2020)

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## cinephile (Feb 27, 2015)

A couple of additional questions about this whole setup:

While Damien made it very clear that this hybrid transmission, since it originally was intended to have a gas V6 in front of it, can handle quite a bit of power going through it to the output flange I am interested in the overall lifespan of the two motors themselves when tuned for higher output. The strength of the internal rotating parts of the transmission itself is not in question, then.

He has also been very clear that it is not required to run its motors up to the maximum of 650V that it was designed to handle (in very short bursts in a stock GS450h).

His last posted testing voltage was at 360V with noted sag in the battery he was using and at that level he was outputting around 120kW or about 160hp. And for many potential applications that is pretty good.

So what I am wondering is... thinking on what the MG1 and MG2 motors themselves can endure 24/7... if a much more uprated battery setup were used (I won't get into the weight or packaging constraints at this moment) with open-inverter parameters allowing for a modest regular all-day daily driveable baseline of 150kW (about 200hp) or even 190kW (around 250hp)... does it stand to reason that the MG1 and MG2 motors themselves will be able to hold reliably at that current and voltage level on a regular basis?

I think I read somewhere that the theoretical maximum output for this system might be 270hp or so but just sticking to achieving a regular output of 200hp or 250hp would that be asking too much such that the two motors would burn out very prematurely or might anywhere between the total all-day-long output of between 150-190kW (if you ask the motor to draw that much current at any given time) still be considered reliable?

I know that when cruising along especially if the motors are not revving exceptionally high there will not be close to the total current draw on them as far as they will be tuned.

I'm just trying to get an idea of whether or not this system can handle power in that range for a larger car without potentially harming and drastically shortening the life of the MG1 and MG2 motors.


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## John_G (Jun 6, 2020)

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## brian_ (Feb 7, 2017)

Any comparison of ratings for motors or engines is all about rating conditions. Industrial motors are rated for continuous operation, so in intermittent service they can be run at much higher than their rated power. Neither electric motors nor engines in automotive applications are expected to run at their rated power for more than a few seconds at a time.

It is completely inappropriate to take a random power rating for an electric motor and assume due to some magic superiority of electric motors that it can be reasonably used at much higher power, even though motors from some specific applications with low ratings may run successfully at much higher power, in different conditions and usually with different controllers.


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## brian_ (Feb 7, 2017)

cinephile said:


> So what I am wondering is... thinking on what the MG1 and MG2 motors themselves can endure 24/7... if a much more uprated battery setup were used (I won't get into the weight or packaging constraints at this moment) with open-inverter parameters allowing for a modest regular all-day daily driveable baseline of 150kW (about 200hp) or even 190kW (around 250hp)... does it stand to reason that the MG1 and MG2 motors themselves will be able to hold reliably at that current and voltage level on a regular basis??


In EV mode, only MG2 is driving the vehicle, and performance is very limited compared to hybrid (engine running) operation. In normal (engine running) mode, most of the engine output is flowing through the power splitter gearset and to the output without using either motor-generator; in parallel, some power is flowing through the power splitter gearset to MG1 and then electrically to MG2, or to MG2 and then electrically to MG1 and out through the power splitter gearset (depending on the combination of road speed and engine speed). This split power flow is integral to the way the HSD works, and is important to its efficiency (because it routes substantial power through a fully mechanical path instead of a much less efficient generator-motor pair). The result is that the amount of engine power handled by the transmission system doesn't indicate the amount of power which the motors can produce by themselves.

This is not a series hybrid system - it is not even capable of operating in series mode (unlike some other hybrids). In a purely series hybrid design (BMW i3, Nissan e-Power) you can assume that as a battery-only EV the same power can be sustained by the drive motor as with the engine... but again, the Toyota system is not a series hybrid.


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## John_G (Jun 6, 2020)

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## John_G (Jun 6, 2020)

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## brian_ (Feb 7, 2017)

cinephile said:


> While Damien made it very clear that this hybrid transmission, since it originally was intended to have a gas V6 in front of it, can handle quite a bit of power going through it to the output flange I am interested in the overall lifespan of the two motors themselves when tuned for higher output.* The strength of the internal rotating parts of the transmission itself is not in question, then..


The same transmission was used in the XF40 generation Lexus LS 600h, which had a 394 HP 5.0L V8. I agree... although that only means that the two-speed planetary gear set on the output can handle lots of power, the power splitter isn't an issue either. The total system output rating says nothing about the gear sets which link MG1 and MG2 to the other components, but I would guess that they'll be fine, too.



cinephile said:


> So what*I am wondering is... thinking on what the MG1 and MG2 motors themselves can endure 24/7...
> I'm just trying to get an idea of whether or not this system can handle power in that range for a larger car without potentially harming and drastically shortening the life of the MG1 and MG2 motors.


The likely durability issue would be related to excessive heat. As long as the motors are operated within the peak voltage and peak current for which they are designed (even though they wouldn't normally see those peaks simultaneously), the concern would be cooling. The unit has cooling capacity for the worst conditions expected in the intended application, not continuous high-power operation, particularly of both motor-generators at the same time.
Years ago there were discussions of using the Highlander Hybrid's rear drive unit as the only drive unit for a DIY EV, and it was quickly realized that it has enough power for many projects (even without driving it past it's Toyota-rated output), but it can only sustain that briefly before overheating. It is intended to briefly drive only when the Highlander's front tires slip; if it were intended to drive continuously it would have better cooling.

Any the test of what components can handle needs to answer the question "for how long"? Many builders do some interesting stuff, but the entire operating life of one of their projects (before they abandon it, or tear it apart and go on to something else) probably wouldn't compare to a single testing day at any auto manufacturer, and almost no FIY builder uses even a small fraction of the test instrumentation that a serious test would require.


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## brian_ (Feb 7, 2017)

A key feature of the design of Toyota's Hybrid Synergy Drive is that it only works as a power-split system, so it is unable to transmit engine power to the output without the electric motor-generators. Similarly, MG1 is unable to drive the vehicle at all without the engine working; however, while the HSD cannot transmit power without MG1, not all of the power goes through MG1 and MG2.

For a reasonableness check, consider that as limited by the stock controls the total of MG1 and MG2 output is much less than the engine output, and the car clearly demonstrates greater performance than that total MG output could produce. Why? Because much of the engine's power is mechanically transmitted, not going through the motor-generators.

For those interested in how Toyota's hybrid system works, and unwilling to look up any of the many online descriptions:

the engine and MG1 are connected to the two input sides of a planetary power splitter gearset, which works like having the engine and MG1 connected to the right and left axles coming from a conventional differential (the speed of the driveshaft is proportional to the average of the left and right axle speeds)
the "driveshaft" side of the power splitter is connected to the transmission's output
MG2 is connected to the transmission's output with fixed-ratio gearing
the speed of MG1 relative to the output determines the engine speed (run MG1 faster and the engine must run slower so that their average still corresponds to the road speed)
electrical power produced or used by MG1 to hit that target speed goes to or comes from MG2
when the engine is not running, only MG2 drives (or regeneratively brakes) the vehicle

GM's two-mode hybrid (also used by Chrysler and BMW), including the Volt's Voltec system, and various other hybrids (such as most Ford systems) are more complex variations of this power-split approach.


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## John_G (Jun 6, 2020)

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## MattsAwesomeStuff (Aug 10, 2017)

John_G said:


> Yup, about 1kWh/mile if I recall correctly.


Just about everything you're saying is wrong, or bizarrely out of context.

Like, this statement here. Why are you talking about it's mileage in response to his question? His question had nothing to do with kWh/mile.



> It has L O N G been understood that while mathematically 0.745Kw ~ 1 HP, in practical applications it does not work out that way. Electric motors play WAY above their nameplates.


No, not true. Their nameplates are rated for their circumstances. Look at a 1hp blender vs. a 1hp industrial pump motor. Completely different scales and context behind the ratings.

The math holds up.

The context of the ratings, in different context, would change the ratings.



> you get no driving power without the efforts of MG1 & MG2. It has been proven in the Gen 2 Prius and with the 450H.


Technically true, but contextually false. It doesn't help answer Cinephile's questions.

...




Cinephile said:


> does it stand to reason that the MG1 and MG2 motors themselves will be able to hold reliably at that current and voltage level on a regular basis?


Super simple answer to that. There are temperature sensors on the motors. If they overheat, Toyota will tell the inverter to take it easy.

Graceful failing is something Toyota electronics do quite well.

That said, the lifespan of the insulation on the wires is rated for a certain temperature. I think it's something like 20,000 hours at the rated temp (keep in mind 2,000 hours is a 9-5 work-year, so, even if you drove professionally, 8 hours a day [how would you do that, in an electric car, at max temp, without running out of battery?] all at the max temperature for the insulation, that's still 10 years of lifespan). Above which faster-than-linearly degrades its lifespan. 



> I think I read somewhere that the theoretical maximum output for this system might be 270hp


Ahh hell, way more. The Prius Gen 3 inverter has been tested to handle 433hp just on MG2 alone. If the same ratio is true of the Gen 3 as the Gen 2, it should be able to handle 680hp.

And the GS450H is a heavier duty inverter than the Prius Gen 3.

Gearbox-wise, I don't see why it would be any different. The limitation is cooling and for how long it can be sustained.

Damien's never tested a car at full voltage full throttle. Just lack of battery pack. He threw in some junky cells at lower voltage and he still shot up to highway speed easily. What more does a vehicle need?



> I'm just trying to get an idea of whether or not this system can handle power in that range for a larger car without potentially harming and drastically shortening the life of the MG1 and MG2 motors.


The answer to whether it can handle the power, is whether it has aggressive enough coolant, and aggressive enough cooling.

Otherwise it's an AC motor, it'll live forever.

Say you're using 200kw. On, what, a 50kwh pack? A giant 100kwh pack? That's 15-30 minutes before you run out of energy. You'll run out of ability to abuse the motors long enough for it to matter.

Outside of a racing conditions (or, maybe, towing a motorhome up a hill?), how would you ever drive fast enough to even sustain that kind of power draw? Soon as you're at highway speed your power requirements are back to like, 20-30hp max.


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## gregski (Sep 6, 2011)

I realize this is an "old" thread by some folks standards but the last thing we need is more stand alone GS450H threads, so scold me if you like but I just want to share that I did pull the trigger on one of these Lexus GS450 heich transmotors and could sure use some help in wiring up Damien's VCU, please and thank you

1971 GMCe Lexus GS450H BMW 530e Tesla Model S powered Electruck








1971 GMCe Lexus GS450H BMW 530e Tesla Model S powered...


I will be converting my 1971 GMCe 1/2 ton truck to electric using hybrid and electric car parts here in Sacramento California. This will be a companion thread to the one on 67-72ChevyTrucks.com where I fight rust and do general restoration repairs. I also have a video series on my Good Enuff...




www.diyelectriccar.com


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