Braking..

[Siddhu290]

Not sure if this was discussed earlier. When I brake, the chassis moves forward and back after coming to a stop- more like rocking forward and back. Is this normal?

 

[MerlintheMad]

Can be. We've talked about the rocking forward and backward when applying the parking brake, a very slight movement but noticeable. They could be related. If what you are experiencing isn't producing noise or vibration and the braking is otherwise working as you feel it should, this is probably normal for your car. No two vehicles are exactly alike in how they feel and drive.

 

[Siddhu290]

Yes, that rocking forward and back while releasing from parking brake is evident as well. And it's quite noticeable everytime I come to a complete stop. There are no noises or vibrations though.

 

[ShannonC]

Try braking less aggressively.

 

[Siddhu290]

Try braking less aggressively.

This happens even when I brake very gently. It just rocks back and forth like a jelly.

 

[Soca Boy]

This happens even when I brake very gently. It just rocks back and forth like a jelly.

Take your car in to service and get that checked out.

 

[Ty Davis]

Not sure if this was discussed earlier. When I brake, the chassis moves forward and back after coming to a stop- more like rocking forward and back. Is this normal?

This is normal for this car. I have been meaning to make a post about this (and a few other things I hope Kia addresses for the next generation of Stinger).

I bet your Stinger has the adaptive shocks. Right?
Because the regular shocks don’t seem to do this.

In most cars, when you brake, the nose dips down and rises back up after the stop. Our Stingers with Adaptive Shocks turn the rebound damping up relatively high at low speeds and when braking.

This increased shock stiffness keeps the back of the car from raising up as much during braking and also resists the release of the dive motion in front after the car stops. The effect is relatively flat braking. But those forces resisted by the stiff shock setting at low speeds don’t go away. So even though the shock/spring isn’t diving, now the force is compressing the bushings in the upper strut mounts.

The bouncing you feel front to rear when you stop is the cars weight loading and unloading those upper suspension mounts. Since the motion is occurring on top of the shock/spring, instead of within it, the shocks can’t dampen the motion. Hence you can feel it rocking back and forth on the mounts until the energy of the stop has dissipated.

All of the ECS Adaptive Suspension behave this way. It is especially noticeable stopping in your garage, driveway, parking spot, or any time that you inch forward and brake to a stop. It also exists from stops at higher speeds too.

A lot of people will say their car doesn’t do it, but only because they don’t notice it. Most people aren’t in tune with these kinds of motions and they go unnoticed. But, if you go look for it, it’s definitely there. Additionally, once you notice it, you will always notice it.

Frankly, this motion feels cheap, unrefined, and detracts from the overall refinement of the vehicle around town (or anywhere stop and going are frequent). Highway drivers are less likely to notice this, because they stop and go less. But in the city, in the neighborhood, and or parking it is definitely a nuisance. I surmise Kia felt that most people wouldn’t find it objectionable...

But a car of this nature should come to a complete stop in one smooth motion. It does not.

Right now, the only fix is to soft (limo) stop. That is, brake normally, then in the last few mm of the stop ease off the brake just a bit. By doing this you will reduce the rocking tendency.
On second thought, coilovers with pillow ball top mounts would eliminate this too (but then the car might rock on the tires, rather than the strut mount). Tire, Spring, Strut, and bushing stiffness all have to be an in agreeance with one another to avoid this. They form a system. If Kia chose to do so, the ECS could easily be designed to minimize this rocking, with no detriment to any other area might I add.

Give me a moment and I’ll post up some vids to show everybody what you are talking about, because it’s one of those things most people have probably never noticed.

 

[Ty Davis]

This car has the Electronic Suspension.


To see the issue demonstrated, skip to the braking test shown at minute 4:20 of the video...

You will see the car rock back and forth several times after the stop, until the energy of the stop has disappated. Now, in a full panic stop like this, you can expect a bit of body motion.
The problem is, the car rocks multiple times, even when just braking into your garage. Uncontrolled motion is very offensive to people sensitive to that sort of thing. It’s one of my pet peeves about the car.

 

[Ty Davis]

Now, this is a a Stinger with the regular suspension.

Take a look at the braking tests during the first 30 seconds of the video...

You will notice that without the additional stiffness of the Adaptive Shocks, this car dives a bit more in the front and lifts more at the rear during stops. And even though the rear bounces a bit after the stop, the motion is decoupled from the front a bit. So in this car you don’t get the rocking back and forth. Also, during a regular stop these would be even further minimized.

 

[Ty Davis]

I would like antidive/anti-lift properties and behavior more like this Sentra at minute 3:30 in this video.

 

[Ty Davis]

Check the 3 series out at 4:12 in this video...
Very little undamped rocking after the stop. The dive motion is more completely contained in the shocks/springs, rather than in the tires/bushings.

 

[Ty Davis]

.

 

[ShannonC]

This happens even when I brake very gently. It just rocks back and forth like a jelly.

No issues with mine. I often like to downshift and Stinger nearly comes to a stop by it's self. If no downshifting i brake normally (gently) and don't have any issues.

 

[Waynerm002]

I have noticed this no longer occurs on my Optima after adding lowering springs and I keep saying to my friends how much more stable my Optima Hybrid feels compared to the Stinger. I was planning on getting lowering springs in hopes of eliminating this, but if the issue is the electronic shock, I'm thinking the issue might still be there. Would love to hear from folks that are on lowering springs, with the ECS system, if this issue still occurs. Truthfully, I just want to do the sway bars and not have to lower the car as it is low enough as is already.

 

[Ty Davis]

I have noticed this no longer occurs on my Optima after adding lowering springs and I keep saying to my friends how much more stable my Optima Hybrid feels compared to the Stinger. I was planning on getting lowering springs in hopes of eliminating this, but if the issue is the electronic shock, I'm thinking the issue might still be there. Would love to hear from folks that are on lowering springs, with the ECS system, if this issue still occurs. Truthfully, I just want to do the sway bars and not have to lower the car as it is low enough as is already.

Hopefully, some of the Eibach owners will chime in with their experiences... The problem with that though, is that a lot of people will tell you that it doesn’t do it, going by memory. Those same people might not have even noticed it before in stock form. We need someone to actually go outside and check for this behavior on their Eibach equipped car and then tell us what they find. This sort of thing just tends to go totally unnoticed by most drivers.

And I do agree with you about the Optima... Even in stock form, I think it was a bit more composed than the Stinger in daily driving. For all of the praise the Stinger receives in the press, the suspension setup really is a mess. It handles big bumps fairly well and softly, but manages to transmit far too much road texture and smaller irregularities into the cabin. It takes a fairly smooth road for the Stinger to ride completely smooth.
But on far too many roads there is a constant stream of minor bumpiness fed into the cabin. On top of that, the front and rear suspension are bouncy, afflicted by too much vertical up and down movements. In the end, the ride is too firm in relation to the lack of body control. The Optima seems more refined than the Stinger, because of its ability to stay composed and smooth over more surfaces.

To the Stingers credit, handling is quite good (minus the rear end bounce/wiggle) and grip is phenomenal. Roll/squat/dive are nicely controlled too. It just needs a bit of refinement added for normal driving. What the car really needs is a set of Koni’s, Bilsteins, or other firmer shock. But as they are not now available, I’ll have to get coilovers, because the stock suspension tuning is easily the worst part of the car.

 

[MerlintheMad]

This sort of thing just tends to go totally unnoticed by most drivers.

Bingo. I watched all your video examples and cannot see any significant differences. At near 16K miles, I haven't noticed anything amiss in how the car comes to a stop, either briskly or pulling forward "an inch at a time", as it were. Of course, I have also never driven an Audi, BMW or any other performance oriented vehicle. This is my first. I am definitely classed with "most drivers."

 

[Ty Davis]

Bingo. I watched all your video examples and cannot see any significant differences. At near 16K miles, I haven't noticed anything amiss in how the car comes to a stop, either briskly or pulling forward "an inch at a time", as it were. Of course, I have also never driven an Audi, BMW or any other performance oriented vehicle. This is my first. I am definitely classed with "most drivers."

That’s the thing... your ability to detect this is almost entirely dependent on what you are used to.
Try this for me, and get back to me...
Let your car roll at idle in drive, then slam the brake pedal. Take note of the rocking front to back after the stop. (It is high frequency, and could be easily tuned out) Once you know the motion, you can feel it a bit in most stops... I may have to grab my vid cam show I can illustrate properly what’s going on.

If you do it at night with the headlights on, you’ll see them bounce too.

This will show you the motion the original poster is talking about.

And once you know it, you will see it in regular braking too (though, perhaps to a lesser degree).

Let me know if you don’t see/feel it... It’s been there in my every GT2 test drive, as well as my purchased GT2.

Once again, if your previous car had lots of nose dive and didn’t stop flat, you may have a hard time detecting this. But I assure you, it’s there with the Electronic suspension.

I am also surprised you couldn’t see the difference in the videos posted. Once you *feel* the sensation, you’ll easily be able to *see* it too in the videos.

 

[Soca Boy]

I just pulled mine out the garage today, she’s smooth stopping, nothing like that “jelly” movement that the OP was talking about. Am riding on 20” also.

 

[PythonNF]

That’s the thing... your ability to detect this is almost entirely dependent on what you are used to.


And once you know it, you will see it in regular braking too (though, perhaps to a lesser degree).

Let me know if you don’t see/feel it... It’s been there in my every GT2 test drive, as well as my purchased GT2.

Once again, if your previous car had lots of nose dive and didn’t stop flat, you may have a hard time detecting this. But I assure you, it’s there with the Electronic suspension.

I am also surprised you couldn’t see the difference in the videos posted. Once you *feel* the sensation, you’ll easily be able to *see* it too in the videos.

Well I haven't noticed it in my 2019 GT Limited (GT2) and why would I make a point of trying to notice to notice it if it will bother me after. I'll just drive around in ignorant bliss, enjoying everything about my stinger.

 

[Kazz]

This is normal for this car. I have been meaning to make a post about this (and a few other things I hope Kia addresses for the next generation of Stinger).

I bet your Stinger has the adaptive shocks. Right?
Because the regular shocks don’t seem to do this.

In most cars, when you brake, the nose dips down and rises back up after the stop. Our Stingers with Adaptive Shocks turn the rebound damping up relatively high at low speeds and when braking.

This increased shock stiffness keeps the back of the car from raising up as much during braking and also resists the release of the dive motion in front after the car stops. The effect is relatively flat braking. But those forces resisted by the stiff shock setting at low speeds don’t go away. So even though the shock/spring isn’t diving, now the force is compressing the bushings in the upper strut mounts.

The bouncing you feel front to rear when you stop is the cars weight loading and unloading those upper suspension mounts. Since the motion is occurring on top of the shock/spring, instead of within it, the shocks can’t dampen the motion. Hence you can feel it rocking back and forth on the mounts until the energy of the stop has dissipated.

All of the ECS Adaptive Suspension behave this way. It is especially noticeable stopping in your garage, driveway, parking spot, or any time that you inch forward and brake to a stop. It also exists from stops at higher speeds too.

A lot of people will say their car doesn’t do it, but only because they don’t notice it. Most people aren’t in tune with these kinds of motions and they go unnoticed. But, if you go look for it, it’s definitely there. Additionally, once you notice it, you will always notice it.

Frankly, this motion feels cheap, unrefined, and detracts from the overall refinement of the vehicle around town (or anywhere stop and going are frequent). Highway drivers are less likely to notice this, because they stop and go less. But in the city, in the neighborhood, and or parking it is definitely a nuisance. I surmise Kia felt that most people wouldn’t find it objectionable...

But a car of this nature should come to a complete stop in one smooth motion. It does not.

Right now, the only fix is to soft (limo) stop. That is, brake normally, then in the last few mm of the stop ease off the brake just a bit. By doing this you will reduce the rocking tendency.
On second thought, coilovers with pillow ball top mounts would eliminate this too (but then the car might rock on the tires, rather than the strut mount). Tire, Spring, Strut, and bushing stiffness all have to be an in agreeance with one another to avoid this. They form a system. If Kia chose to do so, the ECS could easily be designed to minimize this rocking, with no detriment to any other area might I add.

Give me a moment and I’ll post up some vids to show everybody what you are talking about, because it’s one of those things most people have probably never noticed.

And now I understand why, when I come to a stop, I often release the brake slightly to "relax" things. It's all been in my head (and my seat, I suppose), but I've obviously felt this and have tried to react to it. Very interesting! Thanks!