openinverter forum

Hey, all. Quite new here. Decided to join and continue my progress with OI.

In the works is my 2002 International 4900 dump truck - formerly a MODOT salt truck. I'll post pictures as soon as I figure out how to.


Currently, it runs a DT466E that peaks at somewhere around 90kW, I believe.

Plans:
Tesla sport LDU as the drivetrain with the transaxle acting as the transfer case.
Fellten 4.1:1 gear swap
Qauife LSD
Driveshaft Shop CV axles adapted to Oshkosh driveshafts
Oshkosh TAK-4 axles front and rear with 6.0:1 final ratio
OpenInverter logic board (provided I can acquire one)
Winston LYP 200Ah cells for a 420v max traction pack. These can peak at 4kA
Viair 380C compressors for the air brakes

At this time, the truck weighs right around 9.5 tons unladen. I have eight of the Winston cells ordered. I'll be using them to start the diesel engine for the time being as the new lead acids batteries I had out in it a couple years ago are already worn down. Once I get the truck to start again, I'll work on selling off the diesel drivetrain to make room for the electric drivetrain.

thats serious
Yes ldu boards are still sold as before here in the shop

johu wrote: ↑Tue Nov 04, 2025 7:15 am thats serious
Yes ldu boards are still sold as before here in the shop

Right on. Looks like West Side EV has the stuff I need

Trying out image posting. Looks like I need to use third-party image hosting. Haven't done that in years.

Could you please use the attach image function? imgurl is blocked in the UK

That's a massive amount of weight to move compared to the donor vehicle, 4x without a load. I'd expect keeping the motor cool will be a big issue. It's a lot of long term stress on the drivetrain too. Just things to consider while planning.

It will be an excellent stress test for people using these drivetrains.

I'd love to see someone try the GS450H gearbox on something this big. It has both oil cooler and water cooling lines so keeping it cool might be well possible. The low gear definitely allows it to make anything move and then you can cruise on the 2nd. Just pick your voltage from 350V to 600V depending on whether you want 200kW or 300kW.

Huh. I didn't get any of today's notifications. Looks like the picture I posted with Imgur worked, but I just searched and saw mentions of using the attachment button that I haven't seen yet. I may be too new on here to attach images yet.

As far as I can tell, the Tesla sport LDU can run at constant 90kW power that the diesel engine is the same at peak power. I should be able to cool the Tesla inverter and motor pretty easily, though I am still open to other motor and inverter options.


I see the attachment tab, now. I'll give it a go.

The subscribe to topic visual is opposite my expectations, checked means not watching, unchecked means watching.

jrbe wrote: ↑Tue Nov 04, 2025 10:45 pm The subscribe to topic visual is opposite my expectations, checked means not watching, unchecked means watching.

Don't quite know yet. This forum is a very different animal, compared to all others I'm on. Ay take me a while to get acclimated to it.

Meant to mention here that I read through all 33 pages of the LDU support thread. Somewhere in there, I think, someone said that somebody out a Tesla LDU in a 19-ton bus and it moved fine. I haven't found said bus yet.


I also intend to make moulds of the hood (bonnet) and doors so that I can remake them in carbon fiber/kevlar with solar cells embedded in them. Window glass will also get changed out for polycarbonate. I don't have current weights of each part, but I roughly estimate that I'll reduce all that weight by 100 pounds or so.

this one

viewtopic.php?t=6145

JNHEscher wrote: ↑Wed Nov 05, 2025 6:18 am Meant to mention here that I read through all 33 pages of the LDU support thread. Somewhere in there, I think, someone said that somebody out a Tesla LDU in a 19-ton bus and it moved fine. I haven't found said bus yet.

Also, if I remember correctly, Edison Motors used an LDU in their first prototype. I seem to recall they had some breakage, but I can't say for certain.

JNHEscher wrote: ↑Tue Nov 04, 2025 11:12 pm Don't quite know yet. This forum is a very different animal, compared to all others I'm on. Ay take me a while to get acclimated to it.

You'll learn it quick. I find this forum to be by far the easiest and nicest to use forum around, once you learn it.

If I had the budget for Cascadia products and adapting their motors to what I would need for a transmission, I'd go for a 425 - https://legacyev.com/products/cascadia- ... 25dz-d-kit

Initially, I considered installing a twin Tesla sport LDU setup, but one looked to be plenty. I'll run some more numbers soon to see what works and what doesn't.

I think HP-wise, you'll have enough, but the durability/strength of the gearing components is a question.

P.S.Mangelsdorf wrote: ↑Fri Nov 07, 2025 1:06 am I think HP-wise, you'll have enough, but the durability/strength of the gearing components is a question.

Exactly that. The torque of the sport version motor is nearly the same is my engine. Horsepower is is a touch over 3x as my engine. I have an Oshkosh 55000 transfer case that I would considering to use, but it weighs approximately 800lbs

I have seen one instance of the rotor shaft stripping out, but I assume that must have been a fluke metallurgical issue, because I have not heard of other reports of that happening. I have seen stories of gears failing.

I do wonder if maybe you should consider keeping the stock gear reduction, and then if the top speed is too limited, modify the axle gears to get the necessary speed. That'd give the drive unit as much advantage as possible. Just remember that you'll need to change the open diff to a spool to use the drive unit in place of the transfer case.

P.S.Mangelsdorf wrote: ↑Sat Nov 08, 2025 10:17 pm I have seen one instance of the rotor shaft stripping out, but I assume that must have been a fluke metallurgical issue, because I have not heard of other reports of that happening. I have seen stories of gears failing.

I do wonder if maybe you should consider keeping the stock gear reduction, and then if the top speed is too limited, modify the axle gears to get the necessary speed. That'd give the drive unit as much advantage as possible. Just remember that you'll need to change the open diff to a spool to use the drive unit in place of the transfer case.

Unfortunately, the stock ratio does t work out well. The OE axle ratio it has now is 3.33:1. I think that limited me to somewhere around 48mph at top motor rpm.

I still plan to run Oshkosh TAK-4 axles with the 6:1 ratio. I bought a 2013 Leaf for dirt cheap last month with ide to use multiple Leaf motors. It has the EM61, so I may run some numbers with the Oshkosh 55000 transfer case ratios and EM57's again. I'm not sure what else to use, at the moment.

For some reason, I was thinking the stock Tesla LDU final ratio was around 12:1. Looking it up, it's actually 9.73:1?


Edit: sat down to runs some numbers with data in front of me -

Current DT466E peaks at approximately 215hp and 540ft.lbs.
MD3060 has a 5.17:1 1st gear. I don't know the torque converter ratio at the moment.
Rear axle has an open diff with 3.33:1 ratio.

Peak torque to the wheels in its current state would be approximately 9,297ft.lbs. peak



Tesla Sport LDU ready-to-go ratings from Westside EV state 636hp and 480ft.lbs.
9.73:1 LDU ratio
Oshkosh TAK-4 ratio 6.0:1 (1.786:1 differential hypoid ratio and 3.556:1 planetary hub ratio).

Peak torque to the wheels with that setup would be approximately 28,022ft.lbs. Believe me, I had to retype the numbers into the calculator a few times to convince myself
With the Tesla LDU setup as stated, my truck would be able to maintain 75mph with a motor speed of 3,478rpm.

I don't doubt that there's still some concerns to has out with the current plans. If anything stands out to you guys, feel free to chime in.

Some goodies came in a couple days ago.

Yinlong 40Ah LTO cells to make an 80Ah 12v battery. This will be for LED lighting, radio, maybe the air compressors, etc.

Set of four Viair 380C compressors to operate the air brakes and horn.

I've done the math. The simplest thing to do is to keep the LDU and your axles, as Mangelsdorf suggested. That will give you a top speed of 60 mph and a torque of 15,000 ft-lbs.

muehlpower wrote: ↑Mon Nov 10, 2025 9:53 am I've done the math. The simplest thing to do is to keep the LDU and your axles, as Mangelsdorf suggested. That will give you a top speed of 60 mph and a torque of 15,000 ft-lbs.

Yeah, dang, I noticed this eve that I missed the decimal in the tire diameter last night. 423" tire was a bit off 9.73 and 6.0 ratios top me out at 35mph.

Main reason I don't want to use the stock axle is because this is currently rear-wheel-drive with an open diff. The kind of vehicle that gets stuck on wet grass, ya know? Lockers are expensive and I would have to reset the ring and pinion. Whenever I can spot another set of Oshkosh axles to put in, those would gain me lockers, full-time all-wheel-drive, and independent suspension.

I'll run some more numbers and hopefully proof-read my stuff better.

Got somewhere with the data on the transmission, today.

Torque converter ratio is 2.44:1 and 1st gear is 3.49:1. With the diesel peak torque and axle ratio, it peaks at 15,313ft.lbs. to the wheels.

As far as weight goes, the Tesla LDU and Winston traction pack come in at a approximately half the weight of the current diesel drivetrain. Alas, I may have to go with something other that Tesla.

This is a maybe -

https://evwest.com/tesla-large-drive-un ... n-gear-set

480 peak ft. lbs x 4.5:1 LDU ratio x 6:1 Oshkosh TAK-4 ratio makes for 12,960 peak ft. lbs.



With those ratios, 70 mph at 15,013 rpm, 65 mph at 13.940 rpm, and 55 mph at 11,796 rpm. For the most part, I never drive this any faster than 55 mph as that's the speed limit for most rural highways.

I'll still be taking somewhere near 3,000 pounds off yet.


I'm still open to other motor and inverter suggestions. I wanted to support OI logic boards.