GS450h gearbox

[Dynfer]

Hello,

Im currently thinking if it would be possible to use the gs450h gearbox still with an ICE (engine) attached to it to use the hybrid powertrain?

What im trying to achieve?
Bundle the GS450h hybrid powertrain to an ICE engine to use the benefits of the electric motors for low end torque.

[tom91]

Yes this is possible.

[Dynfer]

Yes this is possible.

Thanks Tom for the anwser. Are there any specifics required from the engine? Obviously the simplest route would be to use the 2GR it came in from the factory what about a different engine, I pressume it doesnt care beyond the point it gets some torque on the input shaft.

Also im not so sure if this gearbox has some sort of clutch mechanism that would allow to disengage the ICE during operation? I'm planning to use it in a drift car where clutch kicks or locking the rear wheels would be needed.

[tom91]

...

This is an autobox. Also a series hybrid so it will never be able to run in "just ICE" mode. It requires the Emotors to move torque through the gearbox.

https://openinverter.org/wiki/Lexus_GS450h_Drivetrain

[Dynfer]

...

This is an autobox. Also a series hybrid so it will never be able to run in "just ICE" mode. It requires the Emotors to move torque through the gearbox.

https://openinverter.org/wiki/Lexus_GS450h_Drivetrain

Thank You for link, the question was more in line if the gearbox has some sort of coupling with the ICE like the 8hp were solenoids engage the selected gear. So I assume in this case the engine and gearbox cant spin Independently?

[tom91]

It requires the Emotors to move torque through the gearbox.

There are solenoids yes, but these change gear ration for MG2 to output.

Motors do the torque paths. So varying motor speeds and directions change the torque contributions of each. There is no way to fully decouple the engine.

In the conversion to use both E motors the engine input shaft is locked to allow full torque from MG1 to the output.

Slide deck with more info, the GS450h is the same gearbox without the transfercase https://www.slideserve.com/keefe-cooley ... esentation

[sfk]

Is there a sprag clutch between the gearbox and engine to ensure the motors can never turn the engine backwards when it is not running?

[Dynfer]

There are solenoids yes, but these change gear ration for MG2 to output.

Motors do the torque paths. So varying motor speeds and directions change the torque contributions of each. There is no way to fully decouple the engine.

In the conversion to use both E motors the engine input shaft is locked to allow full torque from MG1 to the output.

Slide deck with more info, the GS450h is the same gearbox without the transfercase https://www.slideserve.com/keefe-cooley ... esentation

So lets say by using a conventional clutch (obviously need to modify the bellhousing) it would allow me to decouple the engine? Also would it be possible for example by sending a CAN message (by pressing the cluch pedal) to tell the zombie VCU to disengage the motors (no power output, no braking)?

[T1Terry]

By locking the ICE motor, with a disc brake on the front pulley for instance, this would be the same as locking the input shaft so both MG1 and MG2 were only driven by the battery current being controlled by the Zombie controlled inverter, with the ICE released and fuel supplied, the output of the ICE would be added to the output of MG1 and MG2, but there would be a stumble as the two electric motors initially spun up the ICE before it started to deliver any input to MG1 and MG2's output .... I can't imagine that would be good for drift racing .....

I guess it might be possible to use MG1 as it was originally designed to do, as a generator, then switch power to it so it becomes a drive motor while still being driven by the ICE, but that would be savage on the transmission as well as how the car behaved, suddenly slamming another 250kw plus into the transmission and drive train ..... but with the wheels already spinning, I guess all that torque would be lost due to lack of traction ..... but if they weren't spinning and had full traction .... I'd imagine the transmission, tailshaft and probably the diff would end up on the track in a million pieces .... they aren't built like the full race prepared powerglide tranmissions ..

T1 Terry

[tom91]

as a generator

I dont quite believe anyone in this thread so far has grasped how this is supposed to work as per design of toyota/lexus.

functions of MG1, always coupled to the ICE engine:
1. Starting the Engine
2. Generating power- Managing engine RPM and Torque to get it into an efficient operating point for the wanted power
3. "push to pass" power boost

Indeed if you want full MG1 power with the engine stationair you need a engine lock on the fly wheel. Yet you can still put some power through MG1 before needing this, just be careful to control it.

Here is a deep dive into a toyota gearbox, same sort of setup

In the end you need to define what you want/need your powertrain to do.

If you want to drift only. Why do you need an ICE engine, its overly complicated and heavy. EVs can clutch kick by demanding massive torque from the motor instantaneously.

The largest issues with any sort of hybrid setup is the controls. There will be loads of them and all very specific to just your setup. So you better know how to code and tune two complicated systems in all operating modes.