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Will the original traction control still work on a fwd ev conversion? I am worried about wheel spin in hard accelerations.
 

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I think the answer to that is the same answer your incontinent grandpa gives when you ask him boxer or briefs... Depends.

As I understand, traction control is handled by some ECU, sensored by wheel position sensors, mechanically actuated by selectively applying specific brakes. ... steering may also play if it's going to be picky. If that's correct (at all, or, for the flavor of traction control you have)...

It's definitely possible that it will still work in a conversion. It has the ability to work. The wheels can still give sensor data, the brakes can still be applied, the ECU still exists.

But, as to how the car cooperates with the non-existence of an engine, or emissions, or a bajillion other things and whether it does so gracefully? Who knows.

Some people pretty much disable it all, rip out the whole ECU. Some people try to do CANbus hacking to emulate the engine still being there. Etc etc. Every vehicle is a bit different.
 

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As I understand, traction control is handled by some ECU, sensored by wheel position sensors, mechanically actuated by selectively applying specific brakes. ... steering may also play if it's going to be picky. If that's correct (at all, or, for the flavor of traction control you have)...

It's definitely possible that it will still work in a conversion. It has the ability to work. The wheels can still give sensor data, the brakes can still be applied, the ECU still exists.
Yes, sort of. They're wheel speed sensors, not wheel position sensors. An individual slipping wheel is managed by brake application, and almost no conversion retains the powertrain donor's brake system to make that possible. If both driven wheels are slipping, and to some extent even if only one is, the motor power is reduced, and that should still work (assuming that the wheel speed sensors are retained).

Steering angle is likely only considered in the case of electronic stability control, which is the next level of sophistication above traction control (which in turn is a level above an anti-lock braking system).

Yabert retained the wheel speed sensors from the Bolt that he transplanted into a VW van, and the vehicle works well. He might have a comment on how well traction control works.

The lack of effective traction control in typical conversions using production EV drive units is the reason that limited-slip differential kits exist for Tesla drive units... but limited-slip differentials are generally undesirable in front wheel drive due to adverse handling and steering reaction effects.
 

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but limited-slip differentials are generally undesirable in front wheel drive due to adverse handling and steering reaction effects.

I remember a very powerful Cooper S with a limited slip diff - and it was a bloody nightmare trying to keep it in one lane!!

Even with RWD an LSD is problematic
With an open diff one tyre spins and the other does not "drive" the car --- BUT the non spinning tyre still provides sideways grip so the car does not accelerate but it does go around the corner

With an LSD if both tyres spin then you lose sideways grip as well and the cornering forces are no longer resisted so the car spins
 

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Even with RWD an LSD is problematic
With an open diff one tyre spins and the other does not "drive" the car --- BUT the non spinning tyre still provides sideways grip so the car does not accelerate but it does go around the corner

With an LSD if both tyres spin then you lose sideways grip as well and the cornering forces are no longer resisted so the car spins
True - anything with a limited-slip diff should definitely have traction control to avoid this. Of course this isn't an issue in production cars, since everything new has traction control now.
 

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As an earlier post said, it all depends on how your system handles the missing engine data.
I converted a 2003 Mini Cooper S. I left all the electronics in place. I wanted the speedo and ABS to work.
I discovered somethings went in a limp home mode.
For example, the power steering pump came on with the ignition switch on. Under normal conditions, the system waits until the engine was running before enabling the PS pump.
The ABS did work.
The dynamic stability control did not.
This also seems to have disabled the traction control as well.

So, I don't think you'll know until you get everything together and on the road.

Pull all the wires off the engine and see what codes are thrown.
 

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Will the original traction control still work on a fwd ev conversion? I am worried about wheel spin in hard accelerations.
No the original (electronic )traction control will not. You are still reading the the input from the sensors and feeding it to the ECU (assuming you keep it) but the old ECU is not communicating with your new EV-KIT unless you have bought a special conversion designed for the version of car you are converting. You could use the existing sensors to feed data into your EV-kit but be aware that these are sensors designed for ICE not an EV.
So the only traction control you are getting is the one in the EV kit (which is usually not sophisticated if present anyway).
If you are converting a vehicle with ATM / Torque converter and you are keeping the original Control Unit for the ATM / Torque converter then you can possibly have a more similiar behaviour between your previous car and conversion but then the EV-kit (inverter/motor) must adapt its speed/torque curve to the existing ATM/Torque converter specs. This results in lower efficiency in the EV-kit but could possibly help to retain previous behaviour. We did that to one vehicle 10 years ago but I can not say that the traction control was the same. It was better on lower speeds and worse with "higher" speeds.
 
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