Using the Lexus GS450h V6 and EV transmission

[T1Terry]

The insane title should either scare most away or trigger the inquisitive nature to at least read the first bit, before putting me in the "nutter" category

I am looking at converting a 10 mtr motorhome with a V10 ICE on LPG and petrol coupled to a 6 sp Alison Auto.
I live in Australia, the place with a lot of nothing between major centres, so recharging facilities will be limited to the major highways for the foreseeable future, along with LPG being either not available or as expensive as petrol ... or worse .... and some regions limited to "opal" fuel https://en.wikipedia.org/wiki/Opal_(fue ... %20seeking. for those who are looking a tad confused already.

My idea was to use the GS450h inverter with the "ZombieVerter" feeding into the 6 sp Alison auto direct (no converter) and tuning the GS450 inverter/ZombieVerter to produce no more than the V10 that is connected to it at the moment.

With the V6 still connected, a modified starter motor to pull the starter gear into the ring gear on the flywheel (yes, it actually has one) to lock the input shaft for full EV mode, but unlock the starter gear from the ring gear to enable the V6 to be used as a drive unit for MG1 to charge the battery when needed and the added compression drag to combine with the regen from MG 1 and MG2 for regen braking .......

Clearly, I'm missing something important because it sounds too easy (in my head) to implement, so I'm looking to the wise folk here to tell me where I've missed the vital bits that make my idea impractical .....

T1 Terry

[T1Terry]

Hmmm... either my idea is so ludicrous everyone is still rolling on the floor laughing
or
It didn't even rate a comment
or
No one could get their head around what I was suggesting
or
and here is the most unlikely one, there are no foreseeable reasons why it wouldn't work ....

I've thought on the idea a bit more since the first post, the extended range ICE regen would probably be only engaged when stationary in a parking bay or such, just so the number of conflicting signals regarding road speed and brake operation and the date and page number, so that might remove one of the issues .... That would also allow me to run the V6 on LPG where I can, just to save a few $$, petrol in the "outback" can get up around the AUD$3.50 ltr (around AUD$16 an imperial gal, AUD$13.30 per US/Gal) so better to save a few $$ for beer .... and maybe food, where possible

T1 Terry

[tom91]

How good are you at coding? As this is a complicated system, EV + ICE controls that need to work together. None of this is plug and play and will require alot of custom fab work, wiring and coding, possibly even bespoke electronics.

[T1Terry]

I believe the V6 engine module and hybrid transmission converter/inverter, are two different units connected by a single wire ... well, from what I can follow watching all the relevant You Tube videos and looking through the wiring diagrams.
I only plan to run the V6 while parked up to act as a range extender generator by driving MG1, otherwise, locking the V6 via the ring gear using a locked Bendix gear through the starter motor access hole (that is there for some reason) using an over centre lever mechanism to either lock the gear in, or out.
This way, the hybrid drive runs the way Damien describes, just not using a fixed input locking device but rather holding the input stationary via the ring gear locked V6

T1 Terry

[tom91]

Sure but having MG1 act as a generator you need to write code for it.

What sort of battery pack are you planning to run?

[barracuda816]

I see what you are aiming for, theoretically there is no reason it can't be done but why keep the v6 just to be the generator? would it not make more sense to fit in a small 2cylinder for efficency, weight and space reasons? I would guess you will have to do some CAN bus hacking anyway.

[T1Terry]

Sure but having MG1 act as a generator you need to write code for it.

What sort of battery pack are you planning to run?

Good question, well asked I'm thinking of using either the 64kwh NMC out of the MG4 Essence I have for another EV conversion, or the 51kwh LFP in the MG 4 I pick up as a salvage in a few weeks and upgrade the 51 with the 64 battery pack etc ....
or
A battery pack built out of 200Ah sodium ion cells .... voltage to be determined, but probably the same 400v nom. platform ..... so around 125 cells ....

T1 Terry

Thinking about it further, maybe the sodium ion cells but 2P125S, 400Ah 400v nom.

[T1Terry]

I see what you are aiming for, theoretically there is no reason it can't be done but why keep the v6 just to be the generator? would it not make more sense to fit in a small 2cylinder for efficency, weight and space reasons? I would guess you will have to do some CAN bus hacking anyway.

In something that already weighs 10 tonne, not much point in attempting to reduce weight if it sacrifices the ICE longevity. The V6 would be running under moderate load compared to a smaller ICE that would need to run at near it's peak output, with the sodium ion battery, it would take between 4 and 5 hrs to charge at 40kw, a big ask for a smaller motor .......

T1 Terry

[T1Terry]

Sure but having MG1 act as a generator you need to write code for it.

What sort of battery pack are you planning to run?

I was thinking along the lines or using MG1 as the starter, but driving the 2 motors in regen mode with the transmission in neutral, so the V6 is spinning the motors while the regen is trying to stop them from spinning, but certainly a good question, I hadn't though too deeply regarding that part ..... nor the actual required battery capacity it seems ....

T1 Terry

[Aragorn]

My 2p....

Whats the goal of chaining the L110 and the Allison?

The transmissions job is to convert the high speed of the engine(and motors) down to typical propshaft speeds. The L110 is already doing that. Putting a second gearbox behind it seems redundant, and especially a complicated automatic which is potentially expecting CANBus chat from the original engine management etc... Perhaps theres a question of a lack of torque (even with the low gearing on the L110)? Its certainly going to add significant mechanical complexity.

Theres also a question of longevity here, the L110 being designed for a passenger car where despite high peak output figures, its very unlikely to be expected to continuously produce full power in a typical car application, 10-15 seconds and you're well into illegal speeds. In a large motorhome on the other hand, its VERY possible to sit at full power for minutes at at time, when climbing hills or similar. This is why typical lorry/bus engines and transmissions are physically larger and more robust than car components with similar output. The Ford V10 in your motorhome is probably producing twice the power that the L110 can produce, and will be happy to do so near continuously.

Futhermore, with an engine attached to the front of the L110, you can only use MG2 for traction. MG1 is connected to the engine and can only be used as a starter/generator and to control the PSD ratio. My suspicion is theres a serious lack of power here, especially when combined with the point above. Bear in mind in an actual GS450h, a significant portion of the power is transferred directly from the engine to the wheels mechanically via the PSD. Expecting MG2 alone to replace a >300hp V10 isnt happening.

As others have said, the control issue is also massive. Zombieverter cant do it. At least, not with the existing code. You would need to write your own code to control the whole thing, and getting that right isnt likely to be easy.

[T1Terry]

The aim is to lock the ICE input when driving EV only by locking the ICE motor using the starter gear locked into the flywheel ring gear. That will allow MG1 and MG2 to both provide drive. The idea of putting the auto between the L110 and the actual diff is to allow the auto to take the heavy lifting and add multiple ratios to reduce the required torque load on the L110 to something it could handle on a continuous basis. The peak kw output of the V10 is slightly more than the L110, so the trans is designed to handle that part, the torque from the L110 is an unknown when using the ZombieVerter as far as I can tell from what I've read so far.
The transmission has its own programmable control system, it doesn't need to be integrated with the ICE ECU, it will provide a reverse so no need to mess with what ever programming there will be via the ZombieVerter to provide regen, so that headache will be averted ......

This is all to beat out the practicality of such a conversion, yet to see just what will happen, no guarantee we will even get this Motorhome or that the wife will let me mess with it Well, until she has to put her hand in her pocket and spend her money on fuel

T1 Terry

[T1Terry]

OK, so we have bought the motorhome, step 1 completed. The V10 has poor/no compression in a number of cyls, so it's either fix the engine or swap it out.
In a past life, I worked for a bus company that started swapping out the diesel engine of near twice the capacity for V8 Ford engines and running them on LPG. They added an Allison 4 sp auto behind them so it was easier to find drivers and the whole idea was a great success, outlasting the diesel engines in the continual stop/start operation and only running for 12 hrs or so, then starting up cold again. There were big hills involved, the combination of the 351 Cleveland and the 4 sp Allison, they could out climb the diesel powered bus, even though the engine was around half the capacity.


The logic I'm using is the multiple ratios should allow the L110 to spin under a reduced torque load, the transmission already handles the weight and hill climbing so it is up to the task.
I might try the Lexus V6 and L110 in standard trim and see how that performs, then look at upgrading the L110 output at a later date.
I don't think the L110 would be up to handling all the work without the second transmission to share the drive load, it does look like a strong build, but nothing like the original auto, it is twice the size .....

T1 Terry

[barracuda816]

That's not quite how it works with electric motors unfortunately. Ofcourse there are efficiency and torque curves but if you need x amount of kw to maintain a set speed up a hill it doesn't really matter if that motor is doing 10k rpm of 5k rpm (within reason) it will still draw x amount of kw. Gearing can multiply the torque sure, but the power remains constant (will everything else being equal) If you are replacing a v10 that has an output of (not real figures, just an example) 180kw it will likely be able to do that all day long. But replace that with an electric motor that can output 180kw, it will only be rated to do that for 10 seconds or so, as in a car that is ample. Will be rated something like 180kw for 10 seconds, 80kw for 8mins and continious rating of 35kw. You should do some calculations to see what the motorhome would need to go up a reasonable incline at a speed you are happy with. This will give you an idea of how far out the ratings will be.

The options could be, fit a different motor with the rating you need, fit more motors. Reduce the weight. Reduce the speed. Gearing won't help on its own.

[T1Terry]

In this case, it doesn't matter if the motorhome can maintain the speed up the hill that it could on the flat, more that it can climb the hill at all, this is where multiple ratios enable the motor to spin faster, won't that reduce the current demand, the motor would be under less load if there is an increase in torque at the sacrifice of road speed?

I have no idea how to calculate the continuous rating of the L110 with MG1 and MG2 both driving and the inverter/converter powered direct rather than through the voltage step up module, I believe Damien said that was limited to 35kw .......

T1 Terry

[TongueTester]

Ozzie Ozzie Ozzie!

I think its a cool idea. There is a fairly detailed analysis of MG2's continuous rating in the L110f transmission report (see page 78 of the link below).

https://www.osti.gov/servlets/purl/947393

You might be able to extrapolate that data to get an idea on a combined continuous rating for MG1/MG2 (as in your application).

It will also depend on your battery voltage. I.e the higher your battery voltage, the lower the current at the same power and the less heat dissipation due to elec loses in the stator in EV mode.

The 800V architecture from the Kia / Hyundai EV6 battery pack might be a winner for your application.

Also, if you plan to keep the V6 for 'hybrid' mode you will need to come up with a way to control the hybrid system and be able to switch to 'EV mode'.

My current thinking on this topic is to run 2 x inverters. One for the factory hybrid system (unmodified) and one for an 'EV only mode' controlled by a Zombi inverter.

With so much real estate in your motor home - you could keep the factory hybrid setup including the battery, then run a separate battery and inverter for 'EV only' mode and switch between them as appropriate.

My gut feel is that your motor home will require too much power to maintain highway speed in EV only mode due to its weight and coefficient of drag. But a lower speed EV only mode might be achievable.

As an example, I worked out that I need approx 60-70kw of power to maintain 100kph on a flat road in my 105 Landcruiser (based on its weight and coefficient of drag) when I was doing my back of the napkin maths (copilot assisted).

Also thanks for highlighting the ring gear on the flywheel of the GS450H. I had to go look at the parts diagram to believe you and im still scratching my head as to why its there in the first place?

Its like Toyota wanted us to do these conversions...

Cheers

Peter

[Woodfie]

Yes ,sound cool to me.
the hybrid as a get you home, or to a charger option has good merit, stops that deranged feeling.
This is reply is seeded by the ringear's presence, so a little background first.
With a few hybrid builds behind me, have set up an L110 and Bedford IC, and run on the bench after some calamities with MG1 as starter , and MG2 as the traction drive.. This has been installed and short test runs done in a camper van vehicle.. but not too heavy a one.
Rpm of the IC is set with a potentiometer, say 1500rpm, this spins the IC when MG2 is in park, then add spark and fuel, and as the IC throttle is advanced, MG1 maintains 1500rpm, and IC charges the HV Battery.
When this IC start is initiated when stationary, the vehicle creeps forward, as expected by the powersplit operation..
MG1 is recieved a torque request, to achieve the set 1500rpm IC crankshaft speed, so this is maintained as MG2 is used to propel the vehicle..
So far has done runs around a 300m yard, and some 5km road trips. Early days, and about to do some more trials in the coming month, is the aim.
It is using modified code from the GS450H, for these test runs, if this is helpful to other hybrid enthusiasts, then this basic system seems to work.
A front engine pulley with a disc brake attached is a way of arresting the IC, to do the Prius Sprague clutch trick, and lock the input shaft to allow MG1 to e used for traction purposes in pure EV mode.
The ringear is another thought, with a matching inverted tooth locking segment, maybe 2 at 180° to be nice.

Hope this maybe of help, happy to share what I have.
Woodfie

[T1Terry]

The idea with the disc brake on the front pulley has a lot of merit, it would be easy to engage/disengage as required.

I was working on the idea that with the transmission in neutral, the ICE would be driving both MG1 and MG2 at a faster speed than the throttle input signal and regen would occur .... but to be honest, it hasn't made it past the thought process as nothing has progressed as far as even removing the bits from the Lexus .... it is still on the back of my truck actually

It seems my hard work on the V10 6.8 ltr ICE has paid off and it is driving great at the moment. The motorhome needed to travel back to NSW for a rego inspection and this proved to be a great test run, found a few LPG hoses I'd neglected to tighten and a factory installed problem with the LPG to petrol change over, but that was it.
We decided to visit friends another 600 or so kms away, it drove great there and back, so it might be a while before I need to do the upgrade .... or when LPG and petrol become the liquid gold only the filthy rich can afford

I think Daimien said something about 500vdc being an upper voltage limiting factor, so I'll have to investigate that further.

Merry Christmas to all

T1 Terry