Crazy LDU and SDU ideas, help needed

[santoscollection]

Hi everyone. Long time browser and finally decided to start my project. However I need some assistance before I order a logic board. I need to know if my plan will even work.

I have a BASE LDU and would like to install it in the rear of a Civic, however because of mounting issues I need to place it in front of the drive hubs. So I will need to spin the motor in reverse. (I assume I need the zeroev oil pump) my question is if I also install the front drive unit from a 75D in the front but in normal direction can I just hook up the front unit via can to the rear drive unit? Will it still drive the front one with rear spinning backwards? If not is there a way to control both with one pedal even if there is not torque vectoring. I’m probably getting ahead of myself here. But any help in this would be greatly appreciated!

[johu]

Yes you can couple them via CAN and have them spin in the correct direction

[FJ3422]

Like your idea !
I had the same thoughts. Technically no problem, until I realised what batterypack would be needed to supply the required current during acceleration..

[P.S.Mangelsdorf]

Will it still drive the front one with rear spinning backwards?

Yes. Most likely the easiest way is to run the throttle pedal via CAN and the direction control via 12v. Just change which pin the switched12v is going to.

i.e. to go forward, send 12v to the front motor's "forward" pin and 12v to the rear motor's "reverse" pin. To go backwards, do the opposite. See the wiring diagrams on Damien's GitHub.

[johu]

Yes. Most likely the easiest way is to run the throttle pedal via CAN and the direction control via 12v. Just change which pin the switched12v is going to.

i.e. to go forward, send 12v to the front motor's "forward" pin and 12v to the rear motor's "reverse" pin. To go backwards, do the opposite. See the wiring diagrams on Damien's GitHub.

That said you could even do that connection via CAN

[EV_Builder]

Will it still drive the front one with rear spinning backwards?

Yes. Most likely the easiest way is to run the throttle pedal via CAN and the direction control via 12v. Just change which pin the switched12v is going to.

i.e. to go forward, send 12v to the front motor's "forward" pin and 12v to the rear motor's "reverse" pin. To go backwards, do the opposite. See the wiring diagrams on Damien's GitHub.

I have stated before, you never should do that. Forward motion means that the motor is spinning in the direction what would result in forward vehicle motion.

If you want the motor to spin in the opposite direction you should invert the direction of the motor. Not use the reverse input for forward vehicle movement. Why? Well one day the software is becoming smart and then you are confronted with these choices.

[Lowcoe]

gonna be one fast civic

[santoscollection]

Progress update. Decided on two LDU one in front and one in the rear. Yes for now I’ll have them both turned down as pack power will be an issue

Can the new board control both motors as in rear master and front slave even though they are both LDU?

[P.S.Mangelsdorf]

Can the new board control both motors as in rear master and front slave even though they are both LDU?

My understanding is that you'd need one board in each, and then run the throttle to one, and use CAN for it to tell the other what the throttle position is.

[santoscollection]

Can the new board control both motors as in rear master and front slave even though they are both LDU?

My understanding is that you'd need one board in each, and then run the throttle to one, and use CAN for it to tell the other what the throttle position is.

That’s exactly what I needed to know. Anyway to confirm this and that can from one motor will drive the other? I know it will if one LDU and one sdu but will it work with two LDU?

[Isaac96]

Yes it will work with dual LDU. That's a hell of a lot of power!
The OpenInverter boards are pretty fully configurable. If you have an OpenInverter board in each LDU then they will work together.

[santoscollection]

Yes it will work with dual LDU. That's a hell of a lot of power!
The OpenInverter boards are pretty fully configurable. If you have an OpenInverter board in each LDU then they will work together.

It should be fun. This is my first ev conversion so I’m learning as I go. Not sure if ill be controlling them with just analog inputs or a vcu. I do have a gen2 Tesla charger and a volt dcdc I need to get going also. What are you thoughts on the combo?

[EV_Builder]

Not sure if you forgot/forget but the motors have an internal oil pump which is directional...

Hope you didn't. How did you solve?

[catphish]

Not sure if you forgot/forget but the motors have an internal oil pump which is directional...

Hope you didn't. How did you solve?

There's an of the shelf reverser for the LDU. I'm about to start work on reversing the SDU pump, assuming such a thing turns out to be possible

[santoscollection]

Not sure if you forgot/forget but the motors have an internal oil pump which is directional...

Hope you didn't. How did you solve?

I already have two reverse rotation pumps in the drive units

[iak78612]

Hoping to get an update on your project. I’m thinking about running two LDUs as well and wanted to see how it went for you.

I was also curious, can you take two FWD SDUs and have them both run as slaves via a splitter?

[johu]

No slavery possible.
Each drive unit needs its own logic board. You can then supply them with the same throttle signal to have them run at proportional torque

[iak78612]

So slavery via logic board?

I purchased the TC2 controller and for all wheel drive set ups, The controller sends the same CAN wires to the rear LDU and front DU inverters.

Why can’t those can messages and Power be sent to 2 front Drive units? I have attached the wiring diagram. Thanks!