openinverter forum

then it was off to Ace Hardware (where they treat me like Norm on Cheers since I'm there every day) for some [ahem] hardware

I love these ALMOST on center every time punches

drill sergeant

so this is what we are going for

Fun Level = 0


36" divided by 4 equals enuff sticks for 2 battery modules

so one on top and one on the bottom, upside down, bat style

so this is the Oreo Cookie battery tray design, respectfully stolen from Sir Artur Kustusch





you know the saying: Good EV Converters borrow, Great ones steal!

Nice work, never even thought of mounting bmw modules upside down

I haven't watched the video's yet or maybe I missed it in the post, but how are you handling the power direction going to the rear output shaft instead of the unloaded front input?

I've read about making a locking plate for the input shaft which potentially limits top rpm. I've read about welding the planetary's to lock the input and output shaft together but allow higher output shaft rpm. Or did the control get sorted out to let MG1 spin up in parallel to MG2 to force power rearwards against the MG1 motor rotation? Or am I missing something entirely?

TheSilverBuick wrote: ↑Fri Apr 22, 2022 7:26 pm I haven't watched the video's yet or maybe I missed it in the post, but how are you handling the power direction going to the rear output shaft instead of the unloaded front input?

I've read about making a locking plate for the input shaft which potentially limits top rpm. I've read about welding the planetary's to lock the input and output shaft together but allow higher output shaft rpm. Or did the control get sorted out to let MG1 spin up in parallel to MG2 to force power rearwards against the MG1 motor rotation? Or am I missing something entirely?

I've decided that for Phase I of the build I will as Damien puts it "take one for the team" and only run on MG2 and not even wire up MG1, the reason being I want to see how it effects range and performance, I may even dyno test the truck with MG2 only to see what true horse power it puts out at the wheels, stay tunned

I have not heard anything about "limiting top rpm" you are the first person to state that, where did you get that information I am sure others would like to review it

Looks like it's coming together nicely, please keep on with the updates

Your thread! The last post quotes another thread that I linked below.

viewtopic.php?p=35739#p35739

viewtopic.php?t=1322

sfk wrote: ↑Tue Jan 05, 2021 9:13 pm Worth pointing out that MG1 and MG2 could be operating at different RPM depending if you use the Lock Input Shaft method or Lock Planetary Gearset method.

Locking the planetary gearset will cause them to spin at same speed and direction with a max RPM around 11,000ish due to the limits of the bearings. In High gear 1.9 reduction this will result in about 5,250rpm coming out the back of the transmission.

Locking the input shaft will cause MG1 to spin 2.2x in the opposite direction to MG2. Thereby MG1 will reach the bearing speed limits much earlier than MG2 and limit the total output RPM. This will result in a max RPM of about 2,600.

Divide that by your 3.36 axle ratio and you have your rear wheel RPM and it's just a final step to factor in your tyre circumference to find your max road speed.

But neither locking the input shaft, nor welding the planetaries, I think will cause power to spin MG1/Input shaft instead of the output shaft when serious torque is applied, but perhaps not? In another thread about oil pressure, someone mentioned spinning up MG1 to run the mechanical pump as soon as practical to limit time on the electric one, and the side benefit was it possibly allowed for neither a locked input shaft nor welded planetaries, hence my first question. But the oil pump discussion doesn't have anything to do with your project.

TheSilverBuick wrote: ↑Fri Apr 22, 2022 9:37 pm Your thread! The last post quotes another thread that I linked below.

viewtopic.php?p=35739#p35739

viewtopic.php?t=1322

sfk wrote: ↑Tue Jan 05, 2021 9:13 pm Worth pointing out that MG1 and MG2 could be operating at different RPM depending if you use the Lock Input Shaft method or Lock Planetary Gearset method.

Locking the planetary gearset will cause them to spin at same speed and direction with a max RPM around 11,000ish due to the limits of the bearings. In High gear 1.9 reduction this will result in about 5,250rpm coming out the back of the transmission.

Locking the input shaft will cause MG1 to spin 2.2x in the opposite direction to MG2. Thereby MG1 will reach the bearing speed limits much earlier than MG2 and limit the total output RPM. This will result in a max RPM of about 2,600.

Divide that by your 3.36 axle ratio and you have your rear wheel RPM and it's just a final step to factor in your tyre circumference to find your max road speed.

But neither locking the input shaft, nor welding the planetaries, I think will cause power to spin MG1/Input shaft instead of the output shaft when serious torque is applied, but perhaps not? In another thread about oil pressure, someone mentioned spinning up MG1 to run the mechanical pump as soon as practical to limit time on the electric one, and the side benefit was it possibly allowed for neither a locked input shaft nor welded planetaries, hence my first question. But the oil pump discussion doesn't have anything to do with your project.

I am running this by Artur who has run this transmission with the locked input shaft for a couple years now, also there is a Damien Maguire video where he drives the Bexus with this transmission in it with the input shaft locked out and we can watch the RPMs on the virtual gauges on the screen, and I am pretty sure he is at least a grand above 2,600, just re watched it 4971 RPM around the 5:40 time mark in the video as he gets on the motorway!

TheSilverBuick wrote: ↑Fri Apr 22, 2022 7:26 pmI haven't watched the video's yet or maybe I missed it in the post, but how are you handling the power direction going to the rear output shaft instead of the unloaded front input?

I still need to watch your video! Is your input shaft locked? I've watched Damien's and didn't connect the dots between his rpm and the post. The motor assemblies are likely fine for 10,000-15,000rpm with Toyota engineering factors applied, but until one runs a bearing out or shatters a rotor, its all speculation! I am planning on running both motors and and shifting, in for a penny in for a pound, but I'm ways off on that. I still need to get my 6x6 project back on track.

TheSilverBuick wrote: ↑Fri Apr 22, 2022 10:43 pm I still need to watch your video! Is your input shaft locked? I've watched Damien's and didn't connect the dots between his rpm and the post. The motor assemblies are likely fine for 10,000-15,000rpm with Toyota engineering factors applied, but until one runs a bearing out or shatters a rotor, its all speculation! I am planning on running both motors and and shifting, in for a penny in for a pound, but I'm ways off on that. I still need to get my 6x6 project back on track.

I don't know where these rumors come from but there is no shortage of them when it comes to the GS450h, we all know you MUST have at least 650 volts to get it even to spin, tell me exactly precisely when will you be reving it up to 15,000 RPM, I mean with proper gearing you are doing 75 MPH at 2,500 RPM what more do you need for a steady cruise, and of course it can do 5,000 easy, but why do you need 10,000 this is a motor not an engine there is no traditional power band where you have to be at 10,000 to maximize torque, am I missing something?

Captains Log: Day 67 of the EV Conversion

I spent the entire afternoon/evening just spinning my wheels, ever had one of them days? I think I worked my butt off but honestly all I got to show for it is one hole that I drilled right under the firewall, which took undoing the entire cab and lifting it up 5 feet, that and an empty bottle of Cab

Of course you don't need or want 10,000 rpm, but with the input shaft locked and the planetary gear ratio, MG1 is going to spin faster than MG2, and according to sfk it'll spin 2.2 times faster than MG2, as sfk mathed out in high gear, you'll have the equivalent running of 2600rpm in third gear of the ICE drivetrain. Over that and MG1 will be spinning ~10,900rpm. I don't know where the max rpm spec comes from, but inferring my Bolt's motor max speed is like 8600rpm, and the Leaf's is ~10,400, I would think these Toyota ones are in that neighborhood, plus some engineering safety factor.

With your gearing, you'll be just shy of 80mph, and if that works for you then perfect. I drive my Bolt at 80mph all the time and it's capped at 92mph, so not far of it's limit. 109mph would put your truck's MG1 at 15,000rpm, and that sounds like a lot more than I'd want to go in a 70's truck on 34's

(2600 rpm output shaft, 4,940rpm on MG2 in high gear, 10,868 sympathetic rpm MG1 being driven by MG2 through the planetaries. Damien's video would put the math right here at 11,000 MG1 rpm)


Great video! Motor on!

Damien was driving MG1 and MG2, so MG1 would not have been sympathetically spinning at 2.2 times the rpm as MG2, it would have been contributing to forward motion similar to the planetaries being welded. For the record, I'm not 100% sure that MG1 would in fact run at full counter clockwise rpm, I need to give this more think time with the transmission animation video.

Jack Bauer wrote: ↑Wed Mar 25, 2020 6:26 pm

sfk wrote: ↑Wed Mar 25, 2020 4:14 pm
Looks great. Was MG1 in use and contributing any torque at all or was it just MG2 doing the driving?

MG1 and MG2

TheSilverBuick wrote: ↑Sat Apr 23, 2022 3:37 am... with the input shaft locked and the planetary gear ratio, MG1 is going to spin faster than MG2, and according to sfk it'll spin 2.2 times faster than MG2, as sfk mathed out in high gear,

I am so confused, in the video when MG2 is at 4,971 RPM MG1 is only at 5,964, how is that 2.2 times faster?

Because its variable ratio, if MG1 isn't powered though it maxes out at 2.2 times, but if it its powered it can run at a different speed than MG2/output shaft. Maxes out at 2.2 times, with parasitic drag, etc it may not actually achieve that.

At 5:40 showing MG1 spinning much faster, in reverse, than MG2/output shaft


At 8:40 showing the engine driving MG1, but same effect if MG1 was being powered as a motor, running the same RPM as MG2/output shaft. The magic of planetary gears.


This assumes the video isn't over simplistic and other things are going on. You/we are using it outside it's original design.

mjc506 wrote: ↑Fri Apr 15, 2022 3:19 pm Sorry to hear about your IT issues

Have you compensated for the off-axis EM emissions coupled with the asymmetrical flux linkage distribution and its effects on the variable displacement between transmission housing and inverter envelopes?

honestly I am still trying to come up with some witty response to that, I feel like when you get pulled over by the cop for speeding, and he asks, Do you know why I pulled you over?

and you desperately want to say something smart, but you got nothing, and then after he writes you the speeding ticket and you pull away, you go a gosh darn it, I should have said: well you see officer my ex wife ran off with a cop, and I thought you were trying to give her back!

so here's a peak looksee what we are going for, I don't even know if that Tesla Model 3 battery charger / DC-DC converter combo unit [ahem, sorry Power Conversion System, PCS] is laying on there right side up or upside down, (you tell me, ha ha)

I am also entertaining shoving it under where the oil pan used to live there may be just enough of a cavity to bolt it up to the battery tray from underneath, for that German like impossible to get to to troubleshoot feel

You can set a carburetor on it for car shows!