Dual Motor All Purpose not smooth now

[2kwik4u]

The rear motor needs less power at engagement, it's too much and it's causing a slam. There's no way this is good for the motor.

I would say more appropriately, the power application needs to be better timed with the engagement. You can ramp power up and "catch" the motor speed as it comes up to match wheel speed. Grab too soon and it'll bog down the rest (and feel like a decel), grab too late, and it'll be a jarring acceleration. I think it's a shade to late at the moment.

"Just need to tune the NOS timing and it'll run 9's" <--sorry, couldn't help myself

Sponsored

 

[Jonger1150]

I would say more appropriately, the power application needs to be better timed with the engagement. You can ramp power up and "catch" the motor speed as it comes up to match wheel speed. Grab too soon and it'll bog down the rest (and feel like a decel), grab too late, and it'll be a jarring acceleration. I think it's a shade to late at the moment.

"Just need to tune the NOS timing and it'll run 9's" <--sorry, couldn't help myself

Makes sense.

I'm sure they did the change to improve something. Right now we just need that timing reverted back to the previous levels and have them go back to the drawing board on fixing whatever they tried to fix with 51.

 

[CANCERDOC]

This! I have also noticed this after the .51 software update. It is very noticeable when accelerating to pass on the highway. The rear motor engaging produces a noticeable clunk. Clearly they reprogrammed something but it is definitely not as smooth as before.

 

[MountainBikeDude]

The Gen 1 Quad R1S loaner I drove for a week had none of that issue, even in conserve mode (not sure if there is a mechanical clutch on the quads to even feel to be honest).

Gen 1 Quad uses a completely different system. All drive modes EXCEPT for Conserve, run all 4 motors, all the time. Only when you select conserve mode, will it decouple the rear half shafts using an external magnetic "dog clutch" on either side of the rear motors.
Edit* Conserve mode only runs the front motors, regardless of user power demands etc unless you change out of conserve.

The dual motor is mechanically different in many ways, but part of it was the inclusion of a magnetic clutch within the motor housing, that can engage/disengage with the rear motor depending on speed and power demand. Unfortunately both software and mechanics need to have precise timing to make that transition imperceptible to the driver, or at least as much so as possible.

Super informative video if you care to watch. Starts at the disconnect portion, but the entire video is pretty neat.

 

[BCondrey]

Gen1 DM 2024 and I have not noticed any difference. Just finished a 500 mile trip post-update.

 

[CANCERDOC]

I would say more appropriately, the power application needs to be better timed with the engagement. You can ramp power up and "catch" the motor speed as it comes up to match wheel speed. Grab too soon and it'll bog down the rest (and feel like a decel), grab too late, and it'll be a jarring acceleration. I think it's a shade to late at the moment.

"Just need to tune the NOS timing and it'll run 9's" <--sorry, couldn't help myself

Agree with this. It makes sense the clunk has to be with the connect/disconnect with the rear unit. I know 0.51 made some changes to all purpose mode in the trimotor, but on the tri, its AWD all the time in all purpose. So not sure how it would affect the "auto conserve" that the dual motors default to.

 

[Jonger1150]

Agree with this. It makes sense the clunk has to be with the connect/disconnect with the rear unit. I know 0.51 made some changes to all purpose mode in the trimotor, but on the tri, its AWD all the time in all purpose. So not sure how it would affect the "auto conserve" that the dual motors default to.

So Dual Motor "Snow Mode" just makes it have tri-mode efficiency.

 

[CANCERDOC]

So Dual Motor "Snow Mode" just makes it have tri-mode efficiency.

Snow mode is AWD only but softens the throttle and also has lower regen. Not sure it is more efficient than all purpose.

 

[Jonger1150]

Snow mode is AWD only but softens the throttle and also has lower regen. Not sure it is more efficient than all purpose.

Has this been confirmed by Rivian? I see dual motor captures regen from both motors, while AP Mode only captures it in the front.

I'm not arguing that AP isn't more efficient.... I'm sure it is.

 

[mpshizzle]

Has this been confirmed by Rivian? I see dual motor captures regen from both motors, while AP Mode only captures it in the front.

I'm not arguing that AP isn't more efficient.... I'm sure it is.

AP only captures regen on the front.. sometimes. It depends if the rear motor happens to be engaged when you start decelerating or not.

If you hit with enough acceleration to trigger the rear motor, and then immediately decelerate, it will use both motors

 

[HaveBlue]

Honestly if the motors or gear break from that minor engagement, Rivian isn't going to survive as a company based upon every stick shift, automatic, sequential gearbox, transfer case and locking differential I've driven that shrugs off clutch drops!

 

[TexasBob]

TLDR Call Rivian, this happened to me and they replaced my motor. No issues since.

FWIW I have a Gen 1 dual motor and have no issues with latest update. I DID have this issue, which started suddenly, and I called Rivian. They asked for a time stamp on when it happened (very useful to keep track of this) and the did a remote diagnostic. Motor showed a problem so they had me bring it in right away, gave me a loaner truck, and replaced the rear drive motor. No issues since.

 

[2kwik4u]

@Jonger1150 I purposefully drove the side roads into the office this morning, about 25mi. I struggled to notice the engagement during "normal" driving. I can force it to happen with large throttle swings, but my normal driving style didn't trigger a noticeable engagement.

So, I'm chalking this one up to a non-issue. Hope those of you with bigger concerns get them addressed quickly!

@MountainBikeDude Thanks for sharing the video. Hadn't seen that before.

 

[Jonger1150]

@Jonger1150 I purposefully drove the side roads into the office this morning, about 25mi. I struggled to notice the engagement during "normal" driving. I can force it to happen with large throttle swings, but my normal driving style didn't trigger a noticeable engagement.

So, I'm chalking this one up to a non-issue. Hope those of you with bigger concerns get them addressed quickly!

@MountainBikeDude Thanks for sharing the video. Hadn't seen that before.

Large throttle swings are what engages it now as opposed to pre-update. I think they simply changed the engagement threshold to improve efficiency. Probably a 1 to 2% efficiency improvement accompanied by a clutch-like bump that never existed before.

It drives butter smooth in Snow Mode though. Smooth and seamless at all throttle applications.

 

[PaythePiper]

I’ve noticed that on our Dual - don’t love it and that’s why I got the Tri motor for me. Doesn’t really bother my better 1/2.

Oh, and noticed it as soon as I drove it in Dec - prior to sw update.

I really think they should add conserve mode back in for the dual motor and keep both motors engaged in all purpose

You don’t even know how much I’d love this. Or at least make it rear wheel drive not front. What is this a minivan?

Sponsored