Adaptive Suspension System

[treker]

Let's be thankful Motor Trend did not award the Stinger with Car of the Year. They lack cred and in my opinion the award goes to their major ad revenue generator. Besides, a niche car is best kept a secret.
I have a beef with the softness of the suspension. But there is no porpoising or pitching. My car corners flat as a pancake and handles all lateral forces perfectly. At low speed over speed 'humps' is my problem. But the Nurburgring doesn't have speed humps. They'll issue a software upgrade and fix that soon. If not KIA the aftermarket chippers will.
My car has the Michelin Pilot Sport 4's as well. I'm in a lurch because I an't puttin' no steel wheels with snows on that car! I'll stay home for snow days or do my best to get what I need from the al wheel drive.

I'm wondering whether the current shocks have the range to allow for a greater level of dampening. If they do, it would be great if KIA offered a software update which provided owners the option to do this. I'm also wondering if the suspension tuning in Canada is identical to what it is in the U.S.

Important: Unless KIA had Michelin significantly alter the tire compounding for the Stinger, it is not safe to run these summer Michelins at temperatures approaching and below freezing. Doing so likely will destroy the tires and I expect would be a serious safety issue. Did the KIA dealer (or the tire documentation) bring this up?

Really interesting you are experiencing flat cornering (lots of reviews commented on excessive leaning during cornering) and no pitching etc., though I'm glad to hear it for your sake and ultimately for mine when my car arrives.

 

[SeoulStinger]

The good news is that the Eibach springs can likely replace the stock with improvement across the board for the 'feel' I prefer. A little stiffer. A little lower. And all the benefits of the adaptive damping system.

Glad to hear this. I plan on doing a bit of track time in the Stinger and your comments had me a little worried I might not like the car.

 

[Steve O]

@trekker. Thanks for the heads up on the summer tires. I've got to do something. Like move to California!

 

[Steve O]

Hey [MENTION=50]SeoulStinger[/MENTION], let me know how things go at the track. I haven't had a chance to really assess the suspension as it should be. I think you'll be impressed with the lateral controls like roll pitch and dive. Very impressive in those modes. I am still interested in the vertical control. What the suspension guys call whoops or G bumps. Keep in touch.

 

[VegasStinger]

I'm worried I'm going crazy [MENTION=87]VegasStinger[/MENTION]. I started paying better attention to the suspension at speed (thanks to your comments) and it is very deceptive. It is soft. Normally too soft for my liking. But it is controlled. The body is stable, doesn't dip or pitch, and roll, dive, and squat are amazingly controlled. So at speed the computer and the shocks are doing their job so well I have to reprogram my senses to fixate on what the car is actually doing rather than what the car feels like it would do with a soft suspension. Very interesting...
The biggest problem I have is there are 5 speed 'humps' on the street I take to and from work every day. Over those humps the suspension is way too soft. But there aren't any speed 'humps' on the Nurburgring. LOL.
The good news is that the Eibach springs can likely replace the stock with improvement across the board for the 'feel' I prefer. A little stiffer. A little lower. And all the benefits of the adaptive damping system. Thanks for your help. All it took was a change of expectation and perspective to reprogram this ol' dog.

Give it a little time as there should be plenty of suspension tweaks we can do once more parts hit the market.

 

[StingerMike]

Here's the latest news on suspension parts.

BC Racing - Plans to release coilover products.
Ksport - Plans to release coilover products.
KW Suspensions - Plans to release coilover products in 3 months.

 

[Steve O]

Guys, the Stinger suspension sucks. It hurts to say that. But I speak truth to power. In sport mode I just did some spirited driving and with a g bump in a sweeping corner the car lost all its composure. Corkscrewing with the rear outside bottoming out badly with the inside front popped up. Very bad. I can't believe this was developed on the Nurburgring. What say others that received the car? I am deeply disappointed with the suspension. Coil overs are in the future if I can't get a program upgrade. I can live with the car, but I can't enjoy anything close to it's potential at all. Is anybody is hacking the suspension code in the computer?

 

[upsidedown]

The view I have of my Australian 3.3 GT with adaptive suspension is that it is very jittery over broken surfaces. Now this suspension was recalibrated for our conditions so I'm not sure how it compares with the overseas models but they missed the mark with their setup (car magazines have said the same thing). It also seems a bit thumpy / crashy over low speed bumps or highway expansion joints. I'm not sure whether that's just me getting used to 19" low profile tyres but I do think the dampers could have been setup better to absorb some of those issues. Having said that any changes would probably change the "sporty" nature but I don't think that's a bad thing considering the car is supposed to be a "GT - Grand Tourer" which in my mind also needs to have some suspension comfort.

I would also think that whatever aftermarket suspension is released should also cover both ends of the spectrum regarding those that want something with more comfort / stock ride height and others that want more sporty / lowered. Not sure whether that's possible I guess we'll have to wait and see.

 

[Steve O]

Now I'm going to blow my cover and reveal that I'm a suspension geek and a past shock absorber OEM application Product Manager. Unfortunately that can diminish my credibility because I can be labeled a fanatic/flake by the dealer and ignored if I have a problem that is very hard to describe and even harder to validate without a shock dyno. Anyway...
The problem with the adaptive suspension is that it adjusts compression damping rather than recoil damping. In a vehicle with high sprung weight (like a car chassis/body) to unsprung weight (wheels, tires and half of the control arms) ratio most of the body motions are associated with recoil damping which is not adjustable. Also, most of the wheel control is addressed by recoil damping as the majority of the work (force X distance) done is during recoil. Therefore the only impact of the adaptable suspension is to reduce the compression (squishing down) resistance of the shocks. You feel it as being firmer, but it doesn't impact body motions nor wheel control much. That is why all the testers were saying they couldn't feel much difference. It's also why the car sucks over bumps in corners.
That said, the soft and fixed 'recoil' damping rates, dialled in for comfort, lose control of the wheels (unsprung weight) in harsh conditions. The corner harshness is resonance of the unsprung weight allowing for loss of contact with the road and a skipping out of the rear end.
The fix is firmer recoil damping, but that is not adjustable. So I'm inclined to think my suspension is working fine but is not up to the standard i need to enjoy my drive. I may be meeting with another Stinger GT owner this weekend to compare cars and confirm all is okay with my suspension, but not okay with me. If that's the case i'm going to start researching a set of coil overs that are adjustable. It'll take a while to dial them in but I can guarantee you I'll dial them in perfectly and let everybody know about them. FYI, don't do this at home. Coil overs have the following variables to dial in: ride height, spring rates, spring preloads, low and high speed damping rates for compression and low and high speed damping rates for recoil.
Stay tuned (pun intended)... and forward this observation to Albert Biermann if you know the man.

 

[Speedybee]

So let me try to get my head around all this. (I am no suspension geek by any stretch of the imagination)
You say the suspension is OK part from the bouncing up and down bit and that the difference between modes is not very pronounced.
I have noticed the rear end to be a bit (sometimes a lot), twitchy around longer sweepers on slightly uneven surfaces at higher speeds.
Without going overboard, would the Eibach pro Spring and sway bar kit for front and rear from import shark costing around $600 do a good job in fixing most of this?
And would it then also help make the difference between modes more obvious?
I understand that you guys are very much up to speed with this sort of thing but most of us who own these cars are mere mortals and need things explained in slightly less technical fashion.
We still want performance but if the Eibach solution would give most of us a good fix for a reasonable price and still use the onboard systems can you advise?
Or if there is a better product at a reasonable cost?
I still want to be able to dial in a softer ride for longer family trips, so I want the adaptive suspension kept for me to use.
Would appreciate any more insight on this folks. Many thanks.

 

[Kelly]

[MENTION=386]Speedybee[/MENTION] here is what [MENTION=148]Steve O[/MENTION] thinks about his new ride on Eibachs

https://www.kiastinger.org/forum/threads/422-Kia-Stinger-Eibach-Lowering-Springs?p=7142&viewfull=1#post7142

https://www.kiastinger.org/forum/threads/422-Kia-Stinger-Eibach-Lowering-Springs?p=7173&viewfull=1#post7173

 

[mldavis2]

The car is pretty good as it is. I suspect there are two factors to consider. Implementing recoil damping complicates the suspension and increases cost considerably, although using computerization to control it is not difficult. But second, this is a GT, not an all-out track car. While I've had a fair amount of performance driving training and a bit of track experience, I don't drive my personal car that way.

On the other hand, if you can improve on an already good suspension in upcoming models, go for it. I would suspect it would be an extra-cost option on a GT-Plus model of some kind.

 

[Steve O]

[MENTION=456]mldavis2[/MENTION], and all others that mention the Stinger is not a track car when discussing the poor review I give the suspension: I know it's not a track car. I know a soft cushy suspension can be fine in Germany and Korea, and even on I79 north of Pittsburgh.

But here in Ontario Canada, where the roads are mismanaged by a provincial government that is so incompetent we installed a bridge upside down recently, then paved a road with substandard asphalt for 30 miles then paid the same company to repave it, a soft suspension that is comfortable on good roads is insuficently damped on bad roads.

The Stinger at 140K + is beautifully damped at all four corners. Unfortunately at 120K it is significantly softer and there lies the rub. The stiffness at 140K should start getting dialled in by the softwarre around 80K.

Around town low shock-speed stiffness is not enough. It allows the suspension to compress too much then rebound way too much.

Albert maybe did the tuning on the Nurburgring. But the conditions I am dealing with daily are not on the Nurburgring. So as soon as I can, I'm game for new shock software to improve the Eibachs which were a big improvement already.

I'll get it dialed into to supple and controlled in all conditions and at all speeds. If a software tune doesn't become available by the fall, I'll ditch the adaptive and get adjustable shocks.

 

[upsidedown]

A soft suspension that is comfortable on good roads is insuficently damped on bad roads.

Around town low shock-speed stiffness is not enough. It allows the suspension to compress too much then rebound way too much.

Albert maybe did the tuning on the Nurburgring. But the conditions I am dealing with daily are not on the Nurburgring. So as soon as I can, I'm game for new shock software to improve the Eibachs which were a big improvement already.

I'll get it dialed into to supple and controlled in all conditions and at all speeds. If a software tune doesn't become available by the fall, I'll ditch the adaptive and get adjustable shocks.

Even though the Australian models had a "local tune done" they missed the mark for whatever reason. Pretty much what Steve has said about around town speeds over rough up/down surfaces. And for the back of the car to jiggle around even at 70 kmh over rutty surfaces is just a big indicator that the rear suspension is not being controlled correctly.

I don't see why we shouldn't be able to get a better setup with a change in software but I'm not sure if the adaptive shocks can be made much different just by the software on its own. I think the valving is off so software will only do so much. I know supple and controlled can be had because I've had it in other cars but I'm just not sure with the factory parts it's achievable. I do find SMART mode to be better around town some of the time

Steve I assume that when you say "get adjustable shocks" you mean both in compression and rebound? Does anyone make such a thing yet?

And does anyone know if the OEM adaptive shocks are gas filled. A crazy idea I know but woudn't it be good if we could revalve an OEM shock somehow!

 

[robz32]

While it is a good idea, to revalve the shocks, it is not an economical viable solution. If the point is retaining the adjustability via the use of shock mounted solenoids, then I think a more viable and economical solution will be sourcing a set of Tein Flex Coilovers with the EDFC module. This will allow you to adjust dampening on the fly without sacrificing ride quality. Provided you choose the correct spring rate.

 

[Steve O]

I'm waiting for a software fix. That's step 1. If none becomes available I'll think about changing the shocks. But adaptive shocks usually vary the duty cycle of the valving that is either super soft or super stiff. stiff would be modulated at a frequency of say 50 hz with a duty cycle of 70% stiff 30% soft. Soft would be the inverse. A fix would be 90% stiff and 10% soft for the sport or 'super sport' setting. That's assuming the dampers work like others I've been familiar with. The solenoid is in the same location...

 

[upsidedown]

I'm waiting for a software fix. That's step 1. If none becomes available I'll think about changing the shocks. But adaptive shocks usually vary the duty cycle of the valving that is either super soft or super stiff. stiff would be modulated at a frequency of say 50 hz with a duty cycle of 70% stiff 30% soft. Soft would be the inverse. A fix would be 90% stiff and 10% soft for the sport or 'super sport' setting. That's assuming the dampers work like others I've been familiar with. The solenoid is in the same location...

Steve if I remember correctly I think you said somewhere that the oem shocks are only adjustable in one direction?

Would a software update be enough if that is the case as obviously one direction will have no change whatsoever?

 

[Steve O]

I am only familiar with adaptive shocks that adjust in the recoil direction. Unless it the voltaoreactive fluid shocks like in the Corvette. Recoil (while extending) adjustment only is extremely effective for cars on the road. Off road you benefit greatly from compression adjustment as well. A software update alone can still be effective IF the duty cycle adjustment method is used. I think that's the case because as you go faster the shocks get stiffer. If the shocks are two position (soft hard) without duty cycle modulation, then a software fix will probably not be enough. Adaptive implies multiple settings for multiple circumstances. This is all conjecture eh. But it's fun. When the info comes out from the factory, I could be wrong.

 

[upsidedown]

Yes would be good to know what method they use

I suspect that it is some sort of duty cycle as the smart mode does seem to feel somewhere between comfort and sport. So not just hard or soft

 

[brandon.mol]

Yeah, I feel like eco mode is different than comfort for the suspension but can't put my finger in how exactly...