Acceleration surges coming out of a corner

[DTown3011]

I'm just guessing here, but

I guess: your tires are spinning and this is traction control where it can go from 100% to 0% 100 times a second as a reactionary measure.

I believe the OP is seeing stability control and possibly a mix of traction control where it's being proactive by reducing the throttle's maximum (which you can see on the throttle diagram during these events it lowers the max power)

I can tell you, without question, I am not spinning my tires. These are slow accelerations from a dead stop at traffic lights, etc and there is no way my tires are spinning.

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[AYAYRON]

I can tell you, without question, I am not spinning my tires. These are slow accelerations from a dead stop at traffic lights, etc and there is no way my tires are spinning.

roger that.

Unrelated, but, related: I was on a very long road trip just left the house, put it in conserve mode even though I was not on the highway yet, it just started raining just a bit so the road was damp. The truck has literally no traction in conserve mode, I was barely on the accelerator and as we all know in conserve mode it's slow to begin with, the truck would move sideways like a crab walk, it was very obvious Rivian has not programmed conserve mode to work with traction control. And another tangent: with the new Dual motor "all purpose" mode actually makes the truck FWD over 19mph, I thought hmmmmmmm wouldn't it be smarter to just make conserve mode on the quad motor the same so people can use conserve mode during the entire trip (aka quad motors operate say under 30mph) and rear motors only turn off over 30mph, that would eliminate the need for the user to change modes during the drive and eliminates the uneven front tire wear and all the negatives associated with current conserve mode.

 

[Dark-Fx]

I agree with statements above....likely it's traction control cutting power to the inside wheels in order to maintain stability. Be careful trying to push through that cutback as if things start to bounce/hop on the inside wheels, that's when $$ bits down there can break.

I've never felt wheelhop on my R1 vehicles, have had plenty of wheel spin. I think Rivian's power cutback probably stops it from happening.

 

[Redmond Chad]

I had something similar to this happen to me today, but not out of a corner. I was actually cresting an overpass and felt the same jerking/bucking feeling. Speed fluctuated up and down 1-2 mph and it only lasted a second or two. Very odd. I have a service ticket open for driver + and ACC issues and called to add this on, though neither was engaged when it happened. There have been a couple of times before today that I thought I felt that slight surge and dismissed it, but this was noticable.

I will be very interested to hear what service says about this issue! Please let us know.

I have had plenty of previous EVs with traction control and stability control, and I've taken a lot of corners in a manner where I know they had a chance to kick in...but I've never felt this herky-jerky acceleration be the result before. The cars just smoothly went slower until traction was better. As fast as it can be adjusted, I would think Rivian (or their supplier) could make this smoother. But I understand this is a much larger and heavier vehicle, and the tires are very different. Plus maybe Rivian calibrated it for 22" tires in Sport mode. Who knows.

What drive mode are you in?
Conserve mode disables some motors and could make it more likely to misbehave.
My daughter ran into a cloudburst and the car got squirrelly. Switched to snow mode.

Ah yes, I should have mentioned that. For the last incident, I was in All-purpose mode, Low suspension setting, Soft ride, Standard regen, with Stability control on. For the first incident I'm pretty sure I was in Sport Mode. For the middle incident I don't recall, but it was either All-purpose or Sport, as that's all I've used so far. I haven't put it in Conserve.

 

[diehlryan]

I wouldn't discount pedal control. Inadvertent smallish on/off of the pedal feel like surges. More prevalent if you're on the throttle going over a bumps in a road.

 

[Kunzene]

I wouldn't discount pedal control. Inadvertent smallish on/off of the pedal feel like surges. More prevalent if you're on the throttle going over a bumps in a road.

I’m certainly not discounting that possibility in my case - but I was having other problems on my trip with Driver+ “system fault” alerts, cruise control not holding a set speed, and suspension alerts. Hopeful service can give me some answers one way or another.

 

[Redmond Chad]

I switched tires from AT to AS, and I'm more light-footed on the accelerator...and so far, this issue has not happened to me again.

Perhaps I should try pushing it through corners more? I dunno, the day after I switched tires, I accelerated from a stop while turning, and while I didn't get the herky-jerky acceleration, I did get a big fishtail. My previous EVs never did that, either. That's got me a little shy on the accelerator. But perhaps that was because of the mold-release residue on new tires? Maybe it's worn off by now.

 

[dleepnw]

I tried searching, but not sure what words to use - no luck with the ones I tried. I'm also not really sure if this is a motor, software, suspension or tire issue. So here goes...

I just got my R1S last week. It's on the 20" wheels with all-terrain tires. I have noticed this issue 3 times. I believe all 3 times that it happened, I was accelerating out of a corner (reasonably strong acceleration, but not full acceleration). However, it does not happen every time I accelerate out of a corner.

Basically I feel 3 quick "surges", as if the motor power is being turned on and off (or at least down). It's less than a second from full power to slowing down to full power again. It kind of reminds me of driving my dad's car decades ago when it was running out of gas. Then it stops and the car drives normally.

Could the computers be cutting power? Could this have something to do with all-terrain tire grip (I've never driven on ATs before)? Could something in the suspension be binding? (There are no "bad" noises, although it does seem like the motor noise varies a bit, as if power is really being varied).

Has anyone else experienced anything like this? Any thoughts on what it might be? I'll open a service ticket if it keeps happening, but I'm afraid if I do that now it will just get closed as "unable to reproduce".

never experienced this.

can you provide more info like drive mode, settings in the drive mode, speed when it happens, what youre doing with the throttle. the way you make it sounds seems like the vehicle would be lurching if youre comparing it to a an ICE car "running out of gas".

 

[Riviot]

Did you have ACC or Driver+ engaged in your turns? Those will decrease speed if you're going faster than the truck is comfortable.

 

[godfodder0901]

Did you have ACC or Driver+ engaged in your turns? Those will decrease speed if you're going faster than the truck is comfortable.

And it is NOT smooth when it does it...
Ther will be an indicator with the speed limit icon, which helps you understand why the truck is acting like a spaz.

 

[Redmond Chad]

can you provide more info like drive mode, settings in the drive mode, speed when it happens, what youre doing with the throttle. the way you make it sounds seems like the vehicle would be lurching

Speeds were probably in the 20-30mph range. As noted earlier, drive modes were All Purpose or Sport (other settings listed above). I was accelerating fairly rapidly, but not full throttle. And YES, the vehicle was lurching like there was something seriously wrong with the car. I am sure glad I haven't experienced it since.

Did you have ACC or Driver+ engaged in your turns?

Nope.

 

[Redmond Chad]

Thanks, all, for your thoughts.

I went for a drive again and tried hard to re-create the conditions where I experienced the surging. I did get some wheelspin, and the stability control light did come on...but there were no rapid power surges (and no fishtailing, though that's likely a separate issue). That's great.

I'm not positive why it happened a few times early on, and now appears to be gone. Is it the new tires (Michelin Defender all-seasons as opposed to the Pirelli all-terrains)? Chance, and I'll see it again? Something in the last firmware upgrade? Something unrelated to ESC? Who knows. But in any event, I have a little more confidence in the vehicle.

BTW, I almost missed the stability control light. It's near the lower left corner, which I can easily see while I'm driving straight. But I was in a turn, and the wheel blocked my view of the light at first.

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