Taycan RWS issues ?

[ze_shark]

I am (finally !) the owner of J1.2 Taycan CT4S, 6 days and 1100km.
It has 21" wheels with Pirelli PZero Elect NF1 tires. Car is opionned with Active Ride, Torque Vectoring and Rear Wheel Steering.
And I think i have a problem with the latter.


I quickly starting feeling something odd in Normal mode with all Active Ride options on, strange oscillations from the rear axle at medium speeds (80-100 kph) and large radii (very shallow steering angles). I first attributed it to the PAR lean function, and thought it was an odd side effect as it disappeared in Sport mode.
But i had again a couple of instances where, even with PAR off in Normal mode, the rear end feels unsettled, and i am starting to suspect the rear wheel steering system.

It feels as if the rear axle is jittering between too discrete steering angles, oscillating between too little and too much, which induces a very unpleasant pendulum effect.

Not perceptible in more affirmed corners, neither in Sport Mode.
Happens at constant throttle/speed, so not plausible it would be torque vectoring related.
Does not happen in all cornering conditions, but when it does and i hit that shallow steering angle constant radius condition, i find it very noticeable.

I checked the rear pressures independently from the TPMS and they are evenly balanced at 2.75 bars cold (if cold is a thing in this tropical climate).
I also ran a mapev diag a few days ago and could not see a fault code that could be related.

Any hint/suggestion/related experience ?

I am otherwise thoroughly happy with the car, but this is out of order.

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[r553]

The only thing I could think of is that your wheel alignment might be off? Keep us posted.

 

[Mad Matter]

Just got my CT few weeks ago so I haven't felt this as of yet, I have RAS but no torque vectoring but it could be a condition from the AWD system that at certain speeds the axle binds if its not actually slipping a little bit. So hopefully its normal and just expecting some degree of slip to feel smooth.

 

[chun]

Wheel alignment might be bad?

Did it has 21" from factory? If not, was any alignment done with 21"?

Wheel alignment on taycans needs to be done while it's in its lowest height, so sport plus.

 

[Genau]

The caveman part of my brain wants to know: did you check that all your lug nuts are tight?

 

[SergeyIndy]

This to me sounds like too much suspension tech that does not work well together.
I would like to hear from some else who has the same setup on a 25 CT: AR, RWS, and PTV+.
I know that Porsche took countless hours to tune AR, but how much did they spend tuning all 3 working together?

 

[FlyingPoint]

This reminds me a an experience with a friends car. It behaved just as you have described. It turned out to be a faulty PASM controller. I don't know how this component reacts in the Active Ride mode or if it exists at all, but it seems to be the same old issue with new tech. That is where I would start. If they can't sort it out, suggest they replace the module.

 

[ze_shark]

This to me sounds like too much suspension tech that does not work well together.
I would like to hear from some else who has the same setup on a 25 CT: AR, RWS, and PTV+.
I know that Porsche took countless hours to tune AR, but how much did they spend tuning all 3 working together?

Fair remark, but this combo must not be that rare in well spec'd J1.2s ?
And it is what you find standard in a Turbo GT, albeit with a lower standard ride height.

 

[Vercingetorix]

I would try swapping tires/wheels if possible. Might be Pirellis don’t like the road surfaces.

 

[ze_shark]

Only in Normal mode ?

 

[ze_shark]

So here is an interesting comment that echoes my impressions:

"But here, on uneven—but not bumpy—winding roads, we found it induced an odd side-to-side motion in Normal mode that was genuinely nauseating. And both cars, fitted with the $1330 rear-axle steering, suffered from unsettlingly nonlinear steering feel just off center, whether when initiating a turn or straightening the wheel out of one. We resolved the former complaint simply by switching the Turbo into Sport mode, where the stiffer setup calmed its suspension movements; we'll need to experience a Taycan without the rear-axle steering to know the role it plays in the latter. "

And it comes from the C&D review of the J1.2.

 

[ze_shark]

Motor1, in their review of the J1.2 CT4S with Active Ride, also reports similar issues.
In their own words:

Porsche has also gone really aggressive with its optional rear-wheel steering across its whole lineup. Whereas before you barely knew the rear wheels turned at all, now it feels like the rear is castering around a little bit.

C&D had the benefit of being able to compare two Cross Turismos with RWS, one with Active Ride, and one without.

 

[ze_shark]

Motor1, in their review of the J1.2 CT4S with Active Ride, also reports similar issues.
In their own words:

Porsche has also gone really aggressive with its optional rear-wheel steering across its whole lineup. Whereas before you barely knew the rear wheels turned at all, now it feels like the rear is castering around a little bit.

Still on my lonesome PAR-RWS-CT crusade, i asked Chris Perkins, the Motor1 editor, to comment on the more detailed findings from C&D and my own insights, and whether they sound familiar with his "castering around" comment.

It definitely does sound familiar. I'm not sure what rear-steer settings Porsche changes as you ramp up through the drive modes, but maybe the Active Ride settings in Normal mode exacerbate that feeling. I mostly left the active tilt and pitch control off.

 

[ze_shark]

This is a Panamera review, but a good one, and they talk a lot about Active Ride (in its 400V implementation).



Rear axle wiggles and edginess in Normal mode are still present and disturbing on my car, as incongruous as a pretty girl who snores like a sailor.

But i continue to be in awe for how poised this car is when pushed. No dive, no squat, no turn in inertia, not a shred of body roll, it really pairs brilliantly with the accuracy of the throttle response. All transitions feel surgical and immediate, which is no small feat for a 2.4T barge.

And yet it is very comfortable, filtering far better in primary and secondary damping than the J1.1 CT 4S i drove which traded body control for a much more wooden feel.

I wish the Normal aberrations did not exist, but I have a dial to switch to Sport/+.

The workshop portion of the video also helps convey how much of a technical achievement PAR is. No sway bars, these actuators literally hold the body at all times, unlike PDCC.

 

[W1NGE]

I am (finally !) the owner of J1.2 Taycan CT4S, 6 days and 1100km.
It has 21" wheels with Pirelli PZero Elect NF1 tires. Car is opionned with Active Ride, Torque Vectoring and Rear Wheel Steering.
And I think i have a problem with the latter.


I quickly starting feeling something odd in Normal mode with all Active Ride options on, strange oscillations from the rear axle at medium speeds (80-100 kph) and large radii (very shallow steering angles). I first attributed it to the PAR lean function, and thought it was an odd side effect as it disappeared in Sport mode.
But i had again a couple of instances where, even with PAR off in Normal mode, the rear end feels unsettled, and i am starting to suspect the rear wheel steering system.

It feels as if the rear axle is jittering between too discrete steering angles, oscillating between too little and too much, which induces a very unpleasant pendulum effect.

Not perceptible in more affirmed corners, neither in Sport Mode.
Happens at constant throttle/speed, so not plausible it would be torque vectoring related.
Does not happen in all cornering conditions, but when it does and i hit that shallow steering angle constant radius condition, i find it very noticeable.

I checked the rear pressures independently from the TPMS and they are evenly balanced at 2.75 bars cold (if cold is a thing in this tropical climate).
I also ran a mapev diag a few days ago and could not see a fault code that could be related.

Any hint/suggestion/related experience ?

I am otherwise thoroughly happy with the car, but this is out of order.

Not had experience of AR but RAS (Rear Axle Steering) and PTV+ I've always had and not experienced any issues.

I suspect AR is the culprit and there have been several reported issues with it.

Next stop, dealership.

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