Lexus GS450H motors - How many KW have been achieved on running projects?

[Dan--T]

Hello, I have committed to building an EV around the Lexus GS450H gearbox, donor vehicle is already bought, but I am curious to understand if any body has actually completed a project and done any kind of dyno test to understand the power achieved?

I have eagerly watched all of Damiens Bexus and Lexi videos but it is difficult to judge the acceleration performance in the test drive videos.

Can anybody shed some light on realistic power figures?

My intention is to run in same configuration as Bexus with locked input shaft, using a ~400v battery pack from a salvaged OEM EV, (probably Leaf) and the Lexus inverter.

My hope is that I can achieve around 160kw, does it sound feasible with this hardware?

Thanks
Dan

[slow67]

Hello, I have committed to building an EV around the Lexus GS450H gearbox, donor vehicle is already bought, but I am curious to understand if any body has actually completed a project and done any kind of dyno test to understand the power achieved?

I have eagerly watched all of Damiens Bexus and Lexi videos but it is difficult to judge the acceleration performance in the test drive videos.

Can anybody shed some light on realistic power figures?

My intention is to run in same configuration as Bexus with locked input shaft, using a ~400v battery pack from a salvaged OEM EV, (probably Leaf) and the Lexus inverter.

My hope is that I can achieve around 160kw, does it sound feasible with this hardware?

Thanks
Dan

The motor and inverter are capable of it. Watch Damien’s video here:
https://youtu.be/9eRWR5xXItc

At one point, it was sucking 466 amps from the battery, but the horrible batteries sagged to 260 Volts (from 394V resting). That’s only ~121Kw, but the phase current to the motor wont be any different. Even that same battery current with a stiffer battery would do that (sagging to 343V at the same battery current would get you to your goal).

[Dan--T]

Thanks for the insight, I hadn't thought of working it out theoretically using the figures shown in the video.

Ok it gives me some reassurance I'm on the right path!

[slow67]

Thanks for the insight, I hadn't thought of working it out theoretically using the figures shown in the video.

Ok it gives me some reassurance I'm on the right path!

Read the ORNL study of the LS600H gearbox at the bottom (its the same trans, just with a transfer case). You can see the torque MG2 makes. Lexus rates the gs450 mg2 at 275nm (~400 phase amps).
Now
Torque = phase current
HP = Voltage

Basically a 12v battery in theory could make the full 275nm at stand still. Now with any RPM it quickly goes away (lack of voltage). To increase rpm (and therefore HP) we need more voltage to overcome back emf.

So in short, to make your power you want (*if the inverter only drew 466 battery amps (I think it will draw more), then you increase volts to get your desired power.



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

[arturk]

Just came across this thread.
In my setup I was able to draw 505 amps at 358 volts (reported by ISA shunt). This gives you 181kW. Look like this is max original inverter control board allows for.
As other suggested increasing voltage is one way but since you were looking for 160kW then you are OK.

[TheSilverBuick]

Definitely an option I've been keeping an eye on for my '67 T-bird. Given the vehicle weight I'd like to put upwards 400HP in it, but realize it likely will cruise really nice with 200HP and some steep'ish rear gearing.

[arturk]

... will cruise really nice with 200HP and some steep'ish rear gearing...

It definitely will.

I have it in 1998 Jaguar XJR which is 4000+ lbs car originally with 370HP supercharged engine.
I can tell you I am not missing ICE at all. Car is extremely "lively" and whatever overall power loss is well compensated by instant torque of electric drive train.
I may look into some options to increase power down the road but for now I am really happy with current state.

[TheSilverBuick]

Way cool! The T-bird scaled at 4,850lbs so is chunky. The V8 and I suspect iron cased transmission weigh a fair bit, as does 20 gallons of gas. But TONS of room for batteries, especially if the motor is nearly confined to the transmission tunnel. 0-60 in the mid 6 second range is the slowest I'd be completely happy with, but could deal with 10-12 for the enjoyment of the smooth and quiet ride.

[arturk]

Way cool! The T-bird scaled at 4,850lbs so is chunky. The V8 and I suspect iron cased transmission weigh a fair bit, as does 20 gallons of gas. But TONS of room for batteries, especially if the motor is nearly confined to the transmission tunnel. 0-60 in the mid 6 second range is the slowest I'd be completely happy with, but could deal with 10-12 for the enjoyment of the smooth and quiet ride.

Our performance goals are similar, car was 5.3s stock.
Now it weights roughly 100lbs more then stoc with 48kWh of batteries. I am getting 8s 0-60 with no problem.

[Gigas]

Way cool! The T-bird scaled at 4,850lbs so is chunky. The V8 and I suspect iron cased transmission weigh a fair bit, as does 20 gallons of gas. But TONS of room for batteries, especially if the motor is nearly confined to the transmission tunnel. 0-60 in the mid 6 second range is the slowest I'd be completely happy with, but could deal with 10-12 for the enjoyment of the smooth and quiet ride.

Our performance goals are similar, car was 5.3s stock.
Now it weights roughly 100lbs more then stoc with 48kWh of batteries. I am getting 8s 0-60 with no problem.

what batteries are you useing?

[arturk]

BMW plug-in hybrid batteries. In my case X5 45eX. Those are made by Samsung (SDI). Total of 24 modules 2kWh each. Two packs of 355V nominal.

[bobbyj_408]

Arturk, you mention that you're pulling around 505 A, did you use that number when designing the needed components? For example, what size main fuse did you use? What size cabling did you use? What resistor value did you use for the precharge?

Thanks!

[arturk]

I expected to draw 500+ amps.

My conversion is not completed yet so it is not necessarily final setup yet:

• Main fuse is 400A (which sustained current, it will take much more for short period of time). No plans to upgrade.

• Using AWG#2 wires between battery packs and AWG#0 between HV distribution box and inverter.

• Pre-charge resistor is 15ohm.

[bobbyj_408]

Thanks Arturk! Those numbers are super useful. Thanks for the wiring size recommendation.

[jnsaff]

• Using AWG#2 wires between battery packs and AWG#0 between HV distribution box and inverter.

Is your HVJB farther from the inverter than the battery from the HVJB? I would make sense to make the long runs bigger than the short ones. Even Toyota with the Gen4 stuff has the phase wires really puny but they made them only like 10cm or so, so it does not matter that much.

• Pre-charge resistor is 15ohm.

27A of precharge is quite a lot. Damien suggests having a precharge current of about 2A (and even Tesla has not more than 4A).

[arturk]

• Using AWG#2 wires between battery packs and AWG#0 between HV distribution box and inverter.

Is your HVJB farther from the inverter than the battery from the HVJB? I would make sense to make the long runs bigger than the short ones. Even Toyota with the Gen4 stuff has the phase wires really puny but they made them only like 10cm or so, so it does not matter that much.

I realize that AWG#0 from HVJB to Inverter may be overkill because they are short but they do carry current from both battery packs. Since it was not difficult for me to run those relatively thick wires in this case, why not.

• Pre-charge resistor is 15ohm.

27A of precharge is quite a lot. Damien suggests having a precharge current of about 2A (and even Tesla has not more than 4A).

Agree, it may be little high, however 15ohm resistor is being used in BMW with the same battery pack voltage (360V). I am planning to experiment with higher values in the future to check if I can get reasonable pre-charge time. I like it to be under 1s if possible.

[jnsaff]

If precharge time is a worry for you, you could do it early. Like upon unlocking the car so by the time you are seated you can commence your getaway.