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 Suspension Centerfold, Pics & Assessment of Thor's Suspension |
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 Jun 3 2008, 03:55 PM
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QUOTE(raw6464 @ Jun 3 2008, 04:23 PM) Hyundai… pawn to queen 4… check?
[right][snapback]166350[/snapback][/right]
Hahaha, good one Russ. Well, I certainly don't claim that they've fixed anything, I'm just looking for possible weak spots. The two points that I see around the shock itself (the mount to that horseshoe-shaped lifter and the upper shock bushing) that are also candidates for causing knocking noises do not discount the very real possibility that it's internal to the shock itself. Crummy bump stops inside would do it just as well. It's all conjecture at this point since the suspension was unloaded when I took pics and I'm not inclined to go banging on Thor's with a deadblow mallet to help reproduce / precipitate that particular failure... :P I'll savour these first few thousand (good) miles, then... heh!
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Jun 3 2008, 06:16 PM
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QUOTE(boppert1 @ Jun 3 2008, 06:35 PM) I have learned to live with the rattles and clunks but the high-speed wallow and handling uncertainties scare me to death sometimes. I am willing to bet it has a lot to do with the entire setup as a whole: design, layout, parts, materials, etc. There isn't just one thing I can see that makes this suspension bad. It's more like a combo of little things.
I'd also be willing to bet that a change out to a firmer shock (and possibly spring) or better yet an adjustable shock like a koni or kyb agx plus maybe some urethane replacements for all the rubber bushings and mounts would cure a big part of the wallowing ride (probably at the expense of some more noise but i'll take it).
Unfortunately I don't see this day coming as functional aftermarket parts seem to be scarce right now and with all of the uncertainties surrounding the future of the azera, I don't see too many more manufacturers jumping on board anytime soon to support this vehicle. Woe is me...at least until I kiss a guardrail trying to avoid some idiot merging into my lane at speed.
Hyundai King to consumer pawn...check mate
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There is no aftermarket parts because there isn't much you can do with a suspension with a hinged strut... no shocks, springs , tires, sway bars will overcome such a suspension designed... save your money. You can make this car roll, pitch and yaw... standing still.
This post has been edited by raw6464: Jun 3 2008, 06:44 PM
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Jun 4 2008, 04:41 PM
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andyman32;
Great photos and good work!
I did some investigation of MacPherson Strut and Double Wishbone designs (our Azeras are a variant of the latter type) and learned some things about them. I went to two different websites, one was carbibles.com/suspension_bible.html and the other was
auto.howstuffworks.com/car-suspension4.htm ; both of which were very informative.
"The MacPherson Strut design is a lower cost suspension design. It has the advantage of low unsprung weight and lower cost than the Double Wishbone design". It is a design that lends itself to front wheel drive cars quite well. It does have one disadvantage in that as the wheel and lower control arm move up in an arc the camber of the wheel changes considerably.
"The Double Wishbone design uses more parts than the MacPherson Strut design. It provides more control over wheel camber as the control arms move up and down . It also helps minimize roll or sway and provides more consistent steering feel".
The two paragraphs above are paraphrased quotes from the websites I listed.
A very interesting picture is on the How Stuff Works page showing a 2005 Honda Accord Coupe. It has an upper and lower wishbone design very similar to the Azera. Even the long vertical piece to the upper wishbone arm looks almost identical to the Azera design. If you go to the website, take a really good look at the picture of the Honda design.
I do not believe that the design of the suspension on the Azera is inherently a problem, just the execution of some details. I haven't heard any criticism of the Honda design and it is so similar that any problems it might exhibit would be the same as the Azera except for the actual spring and shock components and perhaps the hardness of the bushings used in either design.
I believe that the main problem is the valving of the shock or strut as we are describing it. There might be minor improvements that could be made by using a spring that had variable compression/expansion rates, but that would be a more expensive change or improvement.
Typical shock absorber manufacturers offer at least three types of shocks for a given vehicle, one with OEM performance, a mid-grade shock and a premium shock. The last two types usually provide greater control over bound and rebound of the suspension elements.
My belief is that once after market shocks become available for the Azeras an improvement to ride qualities could be obtained at minimum expense by changing the shocks. I do not believe Hyundai would void the car's warranty just because some owners might change shocks to suit their own needs or desires.
I will likely be patient and wait for the after market parts and have them changed when they become available. Like David, I am getting older and not inclined to try to do that work myself. Most of the cars I have owned over the last 50 years benefited from shock mid-grade or premium grade changes without making the ride harsh. The main improvement was to overall stability in cornering and undulating surface conditions.
:beer:
Joe
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Jun 4 2008, 08:29 PM
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Good catch on the double-wishbone suspension. The only thing that I notice that is substantially different on the Accord suspension is that the strut assembly is canted sharply inward, whereas in the Azera the assembly is bolt upright. This may mean that in a well-designed double-wishbone suspension the shock absorber and springs both are supposed to resist some lateral movement, whereas when they are vertical, they cannot.
THAT looks like a proper design flaw - if I saw what I think I saw in the Honda suspension. And it does make sense.
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Jun 4 2008, 09:34 PM
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QUOTE(joezera @ Jun 4 2008, 05:41 PM) andyman32;
Great photos and good work!
I did some investigation of MacPherson Strut and Double Wishbone designs (our Azeras are a variant of the latter type) and learned some things about them. I went to two different websites, one was carbibles.com/suspension_bible.html and the other was
auto.howstuffworks.com/car-suspension4.htm ; both of which were very informative.
"The MacPherson Strut design is a lower cost suspension design. It has the advantage of low unsprung weight and lower cost than the Double Wishbone design". It is a design that lends itself to front wheel drive cars quite well. It does have one disadvantage in that as the wheel and lower control arm move up in an arc the camber of the wheel changes considerably.
"The Double Wishbone design uses more parts than the MacPherson Strut design. It provides more control over wheel camber as the control arms move up and down . It also helps minimize roll or sway and provides more consistent steering feel".
The two paragraphs above are paraphrased quotes from the websites I listed.
A very interesting picture is on the How Stuff Works page showing a 2005 Honda Accord Coupe. It has an upper and lower wishbone design very similar to the Azera. Even the long vertical piece to the upper wishbone arm looks almost identical to the Azera design. If you go to the website, take a really good look at the picture of the Honda design.
I do not believe that the design of the suspension on the Azera is inherently a problem, just the execution of some details. I haven't heard any criticism of the Honda design and it is so similar that any problems it might exhibit would be the same as the Azera except for the actual spring and shock components and perhaps the hardness of the bushings used in either design.
I believe that the main problem is the valving of the shock or strut as we are describing it. There might be minor improvements that could be made by using a spring that had variable compression/expansion rates, but that would be a more expensive change or improvement.
Typical shock absorber manufacturers offer at least three types of shocks for a given vehicle, one with OEM performance, a mid-grade shock and a premium shock. The last two types usually provide greater control over bound and rebound of the suspension elements.
My belief is that once after market shocks become available for the Azeras an improvement to ride qualities could be obtained at minimum expense by changing the shocks. I do not believe Hyundai would void the car's warranty just because some owners might change shocks to suit their own needs or desires.
I will likely be patient and wait for the after market parts and have them changed when they become available. Like David, I am getting older and not inclined to try to do that work myself. Most of the cars I have owned over the last 50 years benefited from shock mid-grade or premium grade changes without making the ride harsh. The main improvement was to overall stability in cornering and undulating surface conditions.
:beer:
Joe
[right][snapback]166704[/snapback][/right]
<SIGH> The Honda and other double wishbone suspensions DO NOT have hinged struts connecting them to the lower control arm with rubber bushings. They are connected solidily to the axle hub... a big difference. So from a picture from How it works that shows a suspension that "looks like" the Azera, we can draw the conclusion the Azera's problem is just the struts and we should wait for the aftermarket? Please! Yes upgrading shocks and springs can improve handling, but it's more of fine tuning a suspension. What we're dealing with here is way out of that league. If the "fix" was just shock valving and spring tuning this would have been fixed a long time ago. Hyundai had an opportunity to "fix" it with the new struts... there's a reason why they didn't or couldn't. Are we saying Hyundai could but didn't fix the wallowing even though they went thru the effort of engineering and manufacturing "improved" struts and even installed them for nothing... gimme a break! Are these new aftermarket struts going to fix the lateral and axial motion that can be induced with the car standing still where there is NO shock or spring compression and rebounding? Or how about the clunking? Put aftermarket struts on your Azera and you expect Hyundai to still fix any suspension or front end problems that may come along? I haven't read the warranty cover to cover but I'll bet there's a clause in there with something about using Genuine Hyundai parts. Believe what you want. I've beaten this horse to death... no more... fini!
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Jun 5 2008, 06:22 AM
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Well Russ - I think the point for the MacPherson strut is that it DOES connect directly to the hub, it's a simpler setup; I'm fairly certain my S70, Tauruses and Regals all had this configuration. Seemed to work pretty well but as it mentioned in howstuffworks, this configuration is not good for high-performance, high-speed, or otherwise demanding situations, since the wheel camber will change significantly (become more negative) as the strut is compressed.
The Accord diagram being referenced here is a tiny one on the first and fifth pages, I believe. And squinting real hard, it does look almost exactly like the Azera double-A-arm setup, swan-necked hub assembly and all, with the only difference being, as I mentioned, that the Accord's shock assembly appears to be tilted inward, rather than bolt upright. If the shocks are tilted inward (negative camber) relative to the vertical plane of the wheel, then it WOULD absorb some of the body roll, even in the "bounce test" - if you did a bounce test on that kind of setup some of your downward force would be transferred across the frame to the far-side shock and it wouldn't move. Or at least, wouldn't move horizontally.
Since the Azera's is vertical, when you push down, you're pushing down 100% on the shock on that side, and at a standstill, NOTHING in the suspension is resiting lateral movement. The anti-sway bar resists leaning (vertical axis of both wheels leaning out in the direction of a turn), not rolling (body roll relative to geometry of suspension). So there is literally nothing else in the design that pushes back when you bounce or nudge the car.
Again, this isn't about clunking, this is about "wallowing" (body roll relative to the wheels) - but MAYBE this is a credible lead? Something that might really be "wrong" with the design, as opposed to "sub-optimal"?
I have a friend with an '08 Acura TL. Next time she comes over I'll put her car up on ramps and peek at the suspension... she might not want me to take the wheels off but I can ask... it might be enlightening to take some pics and compare!
Cheers all :grin:
This post has been edited by andyman32: Jun 5 2008, 06:25 AM
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Jun 5 2008, 08:16 AM
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Well Joe I wasn't talking about the steering knuckle / hub assembly being tilted inward - I meant the shock absorber & spring. They point inward at the top like the slope on the sides of a tall pyramid. The Azera's are no more than 3 or 5 degrees inward from vertical, best shown maybe in my picture here: http://www.hyundai-forums.com/index.php?ac...pe=post&id=8140It's tilted inward just BARELY - and eyeballing the Honda diagram (which is tiny) it looks like those might be in by 20-25 degrees. Of course it might just be an incorrect perception of the Honda suspension. Still, I'm interested to take the wheels off of one and take pictures! :)
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Jun 5 2008, 10:48 AM
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andyman32; QUOTE Well Joe I wasn't talking about the steering knuckle / hub assembly being tilted inward -
I meant the shock absorber & spring.
They point inward at the top like the slope on the sides of a tall pyramid. The Azera's are no more than 3 or 5 degrees inward from vertical, best shown maybe in my picture here: I went back and read your post again and I apologize for misunderstanding. You are right. Looking at the Azera engineering drawing it does appear that the shock or strut is nearly vertical. That gives the lower control arm an ability to move the shock easier than a design with a greater angle. That contributes to a softer ride, which as the video referencing statements by the Hyundai design team says was the preference of the designers trying to satisfy the Korean customer. :innocent: It appears, looking at the Hyundai engineering drawing of the spring on the Azera, that it is not a variable rate spring. I could be wrong, but most of the car suspensions I saw with variable rate springs had some coil sections closer together than others. We are all getting quite an education about suspensions through all of the group posts! :liebe011: Joe
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