While NVH isn't really something I normally concern myself with, it has been brought to my attention that Multi-Link can help with ride harshness by isolating the loads through the bushings better, and this is probably a contributing factor to its selection given Mercedes' road-friendly approach to the car. Enjoy the video!
From kinematics point of view, there is no difference between the basic operational principles of double wishbone and multilink suspensions: Both of those suspensions are virtual swing arm suspensions, and both of them are formed from 5 links. With double-wishbones, the outboard ends of the 4 links are connected to each other (2 per wishbones) and the steering axis goes through the balljoints. With multilinks, the steering axis is virtual and can be located with little more freedom, for example to archieve centreplane steering, negative sides being the need for more balljoints, and the difficulty of doing any suspension adjustment. With both systems, the fifth link is there to control the steering of the hub. Double wishbones can be built from individual components, one example is the front suspension of 1971 Tyrrell F1 car. Individual links can more easily be built accurately, and if using any type of spherical bearings or ball joints, manufacturing errors have much smaller impact in the assembly or working of the mechanism. Multi-link can be little bit more easily be built in a way that when hitting bumps, the wheel is allowed to move backwards a little bit in relation to the car body, and this can increase the ride comfort (when hitting bump, reduced horizontal speed of the hub + vertical acceleration = the wheel hub does not need to accelerate when travelling up the bump). If built in this way, the multi-link behaves like a virtual semi-trailing arm suspension.
Im fabricating my race car to inboard antisway system & Im trying to calculate the spring rate i need for the torsional rod .in the rocker assembly & all the antisway bar charts i can find don't account for mount location on the control arm so i don't have a accurate starting point or a way to convert the antisway bar #s over to the requirement for a 6" rod Any help would be appreciated
Kyle, please please please make a video where you explain the different types of suspension setups and the ups/downs of each setup. Kindly explain using similar point of views so it would be easier to understand the differences between each setup!
Something that hasn't been touched is that under one wheel bump no vibrations are sent over to the opposite wheel like on an anti-roll bar installation. This is as close as a suspension can come to perfection without being active.
Not only that, but antiroll bars increase responsiveness at a cost of overall grip because they pull against the inner tire and reduce the load on it. Springs and dampers have no effect on load transfer but roll bars do. You can run really stiff springs and get rid of the roll bars to have more even grip between all four wheels and higher total grip but that results in a really harsh ride and with cars that are traction limited you would spin out much easier since you wouldn't be able to load the rear tires
You guys are actually both wrong. As the dampers act on two different modes, they will have different spring and damper rates. So the forces of a single wheel bump is not canceled out and the other wheel will feel an effect of that. Second Anti roll bars do not decrease grip by reducing the load on the inner tire. They do not change the load of the tires at all, they just change the position of the chassis relatively to the wheels. Load on the tires is only determined by cornering radius and speed.
I find multi-link suspension fascinating. the kinematics get a lot more complex but some of the kinematic results and practical implications are really interesting. Each arm being a pure tension-compression link allows them to be really lightweight if they are straight links as seen on this car (an example to the contrary would be the thrust arm on most modern BMWs). The two arms also create a virtual pivot point that extends beyond the physical reach of the arms, so you can have your virtual steering axis in the same place as, say, the physical brakes - not possible with a double wishbone system if your brakes are too big. if you want to limit scrub radius while also controlling kingpin, for instance, this would be advantageous. The steering axis also moves with steering input, this has a minor effect at lower steering angles but can still lead to interesting dynamic camber behavior as the instantaneous caster and kingpin change with steering angle. At the rear, the steering alignment considerations go away, but you can still lower forces through the toe link (and suspension deflection as a result) by minimizing your scrub radius and the moment that the center of mass of the corner assembly has about the virtual "steering" axis by moving the steering axis as desired - again, this steering axis, being virtual with the multilink setup, can be almost anywhere at the rear with steering geometry considerations largely out the window. I would absolutely love to have a long conversation with the suspension engineers that worked on this car, it's a really unique implementation even six years later. We're starting to see more and more complex suspensions (Mustang GTD has dual-lower-link "double wishbone" front, the highly-regarded Lucid Air has a true 5-link front, etc.) but still nothing quite like this to my knowledge. The rabbit hole goes way way deeper than what i mentioned above - bushing compliance, accounting for how the front pushrod outer pickup point on the control arm should technically move with steering, Ackermann considerations, etc. It's crazy how a production (well, "production") car can have such a wild decoupled spring/damper arrangement and it's still not necessarily the most interesting aspect of the suspension system as a whole
Talking about multilink suspension - it effectively puts your pivot points further inside the wheels (less scrub radius) , makers use this for more than 20 years ( VW/ audi, Merc, BMW, Nissan ...) mainly- because cars where getting faster and heavier which forced to use bigger wheels , tyres and brakes , not allowing to position suspension pick up point where they supposed to be. On damping - also it's an rather old concept made possible with damper technology coming where it is now , the only thing that is pretty hard to wrap the head about is - bump or drop on one side should effect another ... Unless damper takes those load's so well it becomes irrelevant. I'd be happy to be corrected . Good job on those videos , been following you for a while now.
The beauty of this solution is its simplicity. I wonder why no one else thought of this. In recent videos of the Project One, I can see that there's no body roll and it doesn't feel bone cracking hard either, seems to glide over the rough bumpy tarmac of the Nurburgring.
At 6:04, wouldn't one have two separate shafts ? Not doing so would effectively relocate/create a "second" rocker pivot point that would, in effect, "lock the rocker on heave and compression? The horizontal damper would then be rendered useless if that was a single shaft! Additionally, looking at the gold mounting base, there are two sets of damper adjustments. High/low speed adjusters- I'm thinking separate left/right adjusters.
The double-jointed outboard links are known as virtual ball joints and are designed to move the effective pivot point further outboard to reduce kingpin inclination, kingpin offset and scrub radius.
This type of heave spring combined with laterally connected antiroll-mechanism is relatively common in road cars. The Citroen hydropneumatic suspension operates like that. Those hydraulic suspension spheres are laterally interconnected making them work like a heave spring. The hydraulic pipe offers some amount of roll damping. And there are lateral antiroll-bars front and rear to prevent the car from tipping over because of the lateral interconnection. About that separation of roll motion and single wheel bump motion. Aren't those two motions actually same motion: Wheels moving opposite directions in relation to each other. No matter how I look at that suspension mechanism, every time the left and right side wheels move in opposite directions in relation to each other, that motion is resisted by the roll spring and heave spring working in parallel. When looking at the rear suspension 3:05 if the left side rocker is rotated clockwice, that motion is resisted by both heave and roll spring because of how those springs are connected to the rocker at the right side. It would be interesting to see modern vehicle where the antiroll-bar is not connected between lateral pair of wheels, but is instead connected between longitudal side-pair of wheels. One for left side and one for right side. Citroen 2CV had this style roll spring (those coil springs inside suspension tubes, during roll or heave motion. During pitch they behave in different way), those spring were just very soft and because of that 2CV leans so much. The British Hydragas/hydrolastic was simple hydraulic version of that. LLTD could be simplified to simple geometrical leverage calculations, and ground shape would have no effect on lltd. I think with those front suspension arms, mercedes has tried to create centrepoint steering geometry using virtual geometries to remove KPI and offset. At least from pictures, it looks like the n-lines of the suspension linkages intersect somewhere around the center plane of the wheels, so the instantaneuous screw axis of the hub should be somewhere around the center of the wheel.
Hi there! Great explanation 👏🏽. Do you know how could potenciometers be applied on the roll damper? Do they need to have two linear potenciometers one for each spring or can it be just one since the springs will have the same symmetric movement?
5:15 ...Upper roll spring cant strech... not retained...so used 2... FEEDBACK FROM AUDIENCE REQUESTED If a retainer was used could this pice be a single spring? Hope the new (years old) job is happy. Cheers. Wish you could work out some kind of deal for a "limited disclosure agreement " of non Co. data or analytics . If nothing else, that you may inspire your replacement who is only 7 years old now.
Shouldn't damping be more soft on single wheel bumps, for more traction on the other wheels ???? Otherwise the car would tilt and I think you would lose traction on two or more of the other wheels.....
By separating the A-arms, they will be getting a 'virtual pivot point' for the steering. This brings the ball joints inboard, which makes room for a better brakes package. I.e. Brings it inboard too which allows for better cooling. Look how inboard the calipers are!
So as some that might want to make this at home with parts you can buy what if you make a x with the shocks and leave the top parallel shock off. Or if a do that would I still need a top shock alone with the x patter on the bell cranks to get the same effects. I'm also guessing I'm not going to need springs with high tensile strength like I would in other set ups. Kinda would like to know how I could go about calculating what springs I need for a weight of the vihicle in a set up like this or the one I described.
Kyle! there is something interesthing abou the rear arms as well! There is an extra rear suspension arm located between the rear arms, a 5th connection. It looks interesting as it seems, if you mentalize the suspension compression motion, as it has a shorter length when compared to the inferior arms, when the suspension gets compressed during heavy cornering centre roll, that arm tends to modify the toe angles accordilgly to the chassis rolling, opening it when compressed, closing it when lifted... Check this video at 7:30 and onwards! please! th-cam.com/video/EzV_1hF4pxM/w-d-xo.html Also, it seems the engine doesn't have the same exhaust manifold the F1 car has. The F1 uses a shorter ram lenght exhaust duct and it makes sense for a road car since spooling time won't be a problem to it given it's electric motor in the compressor and bigger batteries. this buffs the lower rev area. I bet it doesn't have the same cam profile as well. And i see a stressed member chassis which means this car is going to be stiff and light. Only a few car manufacturers make use of the gearbox case as stressed member. Usualy it only suits racing cars.
can you do one on the aston martin one-77 since the shocks are in a very weird position in front of the engine on that pushrod like setup, one on the aventador would be sick too, great video
If you haven't already you should check out greenteam stuttgart's solution to the independent roll and heave spring/dampers. Pretty neat solution that doesn't require a through shock or two springs. On the topic of FSAE Suspension I'd love to see you do a video on AMZ's active damping hydraulically mode separated suspension, a bit of a mind bender.
Hadn't seen it, but pretty neat solution! Hadn't seen the AMZ one either (I haven't been keeping up well with FS lately!) but it looks like a slightly more elegant version of what Monash was running a few years back. I really love seeing these types of suspension out on FS cars.
KYLE.ENGINEERS yeah similar to monash's solution...leave it to the European FS teams to take it to the extreme. I'm on the UQ team and two of our previous cars (2014 & 2016) employed purely mechanical mode separation by using the under tray tunnels as longitudinal beams transmit roll load to a single ARB. Soft warp hydraulic mode separation would probably be ideal for off-road racecars like yours, lots of compliance for all the bumps.
AMZ's suspension system isn't an active one, it's all passive ;-) You also have to mention Rennstall Esslingen's roll heave system in their last two cars I think, but they have one heave damper and two roll dampers and also High-Octane Motorsports roll-heave system in their 2015 car. They only had one roll damper without an spring, but included an anti roll bar as roll spring.
Currently I work on my master's thesis which is about design new type of suspension for lmp1 car based on this idea. It is a lot o fun So far. Let's See what willl be the outcome.
So.... compared to a conventional setup with an anti-roll bar, more stiff on one wheel bumps(two springs and dampers active) and softer on roll, pitch and weight(one spring and one damper active). Hm.... Need furthur clarification on how much spring tension and damping is desirable on each modes.
This German engineering bullshit is a dead meme, look at the average rank of German brands on the reliability index www.reliabilityindex.com/manufacturer
Ladies and Gentlemen, this is not the Index how reliable a brand is but how much a car owner of a certain brand cares about his car and therefore shows how much it is maintained...
Did you even read what you posted? The reliability ratings of German cars are still GOOD. It says so in the link which you posted. Furthermore, there are some brands listed here which sell in such low volume numbers you have to wonder how these cars are ranked and graded. Daihatsu? Chevrolet? Suzuki? These are low volume cars in European markets. In fact Daihatsu is not even sold in Europe anymore. They pulled out due to low sales. The reality is that German cars are high quality, well-made, durable and reliable. I speak from experience. Every brand has cars which are less reliable than their bread and butter products. The whole Porsche lineup for example may be very reliable and low maintenance - except for say the Cayenne. The Cayenne thus brings the whole brand down on a "reliability index." Worst car I've ever owned was a Nissan Cefiro. Do you see me going around hating on Nissan because of one bad car?
The comment above mine is wrong. Of course it produces downforce given it's shaped like a giant wing. It also produces drag which is a byproduct of downforce.
the statement above mine is also wrong, since a windshield is not shaped like a wing at all. But a windshield will partially act like a spoiler as it directs the airflow upwards. And therefore the air will press down on the windshield
Actually, I believe it will provide some amount of lift. As air flows over it and back down over the rear of the car, the movement of the air will cause a low pressure area above the car. If this isn't compensated for by providing a similar affect under the car, it will have a net upwards force on the vehicle. Airplane wings provide lift using this concept, having a curved top that causes the air to move without providing to much drag, causing a low pressure area on top, and a flat bottom that leaves the air as undisturbed as possible to keep the pressure as high as possible. Wings on racecars are similar, but turned upside down, and are far more aggressively shaped because drag is a much smaller issue when downforce is so beneficial. I believe the tops of them are curved because it can provide a ram air effect, raising the air pressure on top at the expense of very high drag. The most important part of them is the bottom though, where the air is made to be at the lowest pressure possible over the largest surface area possible.
What other cars have used this type of suspension? Is there a name for it that I can google? Ive seen a similar thing on Formula-Vee but its for heave only and its to encourage roll. Not minimize it.
The connected bell crank set up is genius. It is ant roll without a roll bar. It takes the preload off the wheel that isn't under pressure from the roll
Can you take a look at "Formula X" from project cars 2? Also why is compliance from the suspension such a problem in F1 but compliance from the tires fine?
Compliance from the tires is not fine, there is just nothing they can do about it since it's heavily regulated, the same for everyone and supplied to them so the suspension has to be designed around it. Thus you get things like mass dampers and inerters.
The prognostication, from 5 years ago, that 'grip is likely going to be obscenely good', appears to have been verified as True, given that the real, road-going (well, if you have USD 2.7m to spend..) AMG ONE, utterly smashed the road legal Nurburgring lap record, last December (ie 2022)
Couldn't they hypothetically use a traditional roll bar as the roll springing mechanism and then only require a typical damper attached to the roll bell cranks?
can one say that this is independent suspension then? I would think by lookin at this that a bump felt by one wheel could disturb the other due to the higher damper.
the problem is with that roll system. corner one way and the damper compress then rebound on return yet corner the other direction the damper droops then compresses on return..since there is one damper on roll...how would they set that up? mechanically speaking if compression and rebound are set at different loads...having one damper handling two opposite characters would be really complicated
Simple, adjust the preload on the heave spring! Or alternatively you could increase the pressure inside the heave damper, which will increase the shaft force.
Thanks! It was very good! but why in this car we don't have an inerter or complicated suspension like on the current Mercedes f1 car? Maybe this suspension is good for this car but personally, I don't see this so complicated! Maybe this is all rubbish, but, it's my opinion!
Note that the ONE was a prototype for a road car, not a race car. If you can call a car than, now it may be bought, costs almost USD 3 million, can fairly be called a 'road car'!
Comparing this car's aerodynamics to that of the P1 doesn't seem to be giving this car enough credit, one look at the interior will tell you that this car is a lot lower than just about anything but the Valkyrie and maybe the probe 16. It seems like it's aerodynamically in between the Valkyrie and the more conventional hyper cars. I have to wonder if the fairly recumbent driving position increases the risk of dozing off on long drives. Also I've never been this interested in fuel economy figures for a hypercar before.
No double a-arms in the back? How is that a revelation? My 1996 C220 has a 5-link rear suspension. Mercedes only recently downgraded to double a-arms on their rear suspensions.
believe or not but toyota has design and manufactured similar suspension on the front suspension,its called superstrut suspension and it can changes caster during steering change and i believe reduces torque steer,it was use in corolla ae111 levin bzr
They did this superstrut on the Celica GT 4. This is not at all similar to the mercedes suspension... But it does indeed reduce torque steer by giving a lower scrub radius for example.
The thing I’ve never understood about these types of suspension is wouldn’t the assymetric setup be more effective to one side than the other? or is that counterbalanced with weight distribution?
If you had an active cartoon of how it worked in motion it would be a lot easier to understand but I know thats expecting a lot and not that easy to produce but I didn't understand anything that was said as interesting as it is. I guess I'm just a dummy. Thanks anyway
Here is not a direction or device action, only where your finger is pointing. I found it quit annoying after the 7th time you employed this term. Try compression, extension, stationary, relaxed or immobile as the the likes of a non-car subject would mindlessly watch. DK, ASE master tech since 78, retired.
While NVH isn't really something I normally concern myself with, it has been brought to my attention that Multi-Link can help with ride harshness by isolating the loads through the bushings better, and this is probably a contributing factor to its selection given Mercedes' road-friendly approach to the car. Enjoy the video!
Do a break down of the aston valkyrie, either aero or suspension
Did you get it backwards when you said under breaking the front wheels will try to lift, but I think the backwheels lift as the weight shifts forward.
Martin Seidl no, he did it's with respect to the chassis
From kinematics point of view, there is no difference between the basic operational principles of double wishbone and multilink suspensions: Both of those suspensions are virtual swing arm suspensions, and both of them are formed from 5 links. With double-wishbones, the outboard ends of the 4 links are connected to each other (2 per wishbones) and the steering axis goes through the balljoints. With multilinks, the steering axis is virtual and can be located with little more freedom, for example to archieve centreplane steering, negative sides being the need for more balljoints, and the difficulty of doing any suspension adjustment. With both systems, the fifth link is there to control the steering of the hub.
Double wishbones can be built from individual components, one example is the front suspension of 1971 Tyrrell F1 car. Individual links can more easily be built accurately, and if using any type of spherical bearings or ball joints, manufacturing errors have much smaller impact in the assembly or working of the mechanism.
Multi-link can be little bit more easily be built in a way that when hitting bumps, the wheel is allowed to move backwards a little bit in relation to the car body, and this can increase the ride comfort (when hitting bump, reduced horizontal speed of the hub + vertical acceleration = the wheel hub does not need to accelerate when travelling up the bump). If built in this way, the multi-link behaves like a virtual semi-trailing arm suspension.
Im fabricating my race car to inboard antisway system & Im trying to calculate the spring rate i need for the torsional rod .in the rocker assembly & all the antisway bar charts i can find don't account for mount location on the control arm so i don't have a accurate starting point or a way to convert the antisway bar #s over to the requirement for a 6" rod
Any help would be appreciated
Kyle, please please please make a video where you explain the different types of suspension setups and the ups/downs of each setup. Kindly explain using similar point of views so it would be easier to understand the differences between each setup!
I'll give it a shot, added to the video requests list!
Thank you very much, sir! :)
Seconded!
I agree. Can you please also include Mcphearson, Independent, double control arms, and integral link seen on the Jaguar XE? Thank you so much
I agree to this as well! This would be great!
Something that hasn't been touched is that under one wheel bump no vibrations are sent over to the opposite wheel like on an anti-roll bar installation. This is as close as a suspension can come to perfection without being active.
Not only that, but antiroll bars increase responsiveness at a cost of overall grip because they pull against the inner tire and reduce the load on it. Springs and dampers have no effect on load transfer but roll bars do. You can run really stiff springs and get rid of the roll bars to have more even grip between all four wheels and higher total grip but that results in a really harsh ride and with cars that are traction limited you would spin out much easier since you wouldn't be able to load the rear tires
You guys are actually both wrong. As the dampers act on two different modes, they will have different spring and damper rates. So the forces of a single wheel bump is not canceled out and the other wheel will feel an effect of that. Second Anti roll bars do not decrease grip by reducing the load on the inner tire. They do not change the load of the tires at all, they just change the position of the chassis relatively to the wheels. Load on the tires is only determined by cornering radius and speed.
Also of course do springs and dampers affect load transfer.
Thank you so much for this! I've been trying to explain to a few friends how it works, and wasn't doing a very good job of it.
I find multi-link suspension fascinating. the kinematics get a lot more complex but some of the kinematic results and practical implications are really interesting. Each arm being a pure tension-compression link allows them to be really lightweight if they are straight links as seen on this car (an example to the contrary would be the thrust arm on most modern BMWs). The two arms also create a virtual pivot point that extends beyond the physical reach of the arms, so you can have your virtual steering axis in the same place as, say, the physical brakes - not possible with a double wishbone system if your brakes are too big. if you want to limit scrub radius while also controlling kingpin, for instance, this would be advantageous. The steering axis also moves with steering input, this has a minor effect at lower steering angles but can still lead to interesting dynamic camber behavior as the instantaneous caster and kingpin change with steering angle. At the rear, the steering alignment considerations go away, but you can still lower forces through the toe link (and suspension deflection as a result) by minimizing your scrub radius and the moment that the center of mass of the corner assembly has about the virtual "steering" axis by moving the steering axis as desired - again, this steering axis, being virtual with the multilink setup, can be almost anywhere at the rear with steering geometry considerations largely out the window.
I would absolutely love to have a long conversation with the suspension engineers that worked on this car, it's a really unique implementation even six years later. We're starting to see more and more complex suspensions (Mustang GTD has dual-lower-link "double wishbone" front, the highly-regarded Lucid Air has a true 5-link front, etc.) but still nothing quite like this to my knowledge. The rabbit hole goes way way deeper than what i mentioned above - bushing compliance, accounting for how the front pushrod outer pickup point on the control arm should technically move with steering, Ackermann considerations, etc. It's crazy how a production (well, "production") car can have such a wild decoupled spring/damper arrangement and it's still not necessarily the most interesting aspect of the suspension system as a whole
Talking about multilink suspension - it effectively puts your pivot points further inside the wheels (less scrub radius) , makers use this for more than 20 years ( VW/ audi, Merc, BMW, Nissan ...) mainly- because cars where getting faster and heavier which forced to use bigger wheels , tyres and brakes , not allowing to position suspension pick up point where they supposed to be.
On damping - also it's an rather old concept made possible with damper technology coming where it is now , the only thing that is pretty hard to wrap the head about is - bump or drop on one side should effect another ... Unless damper takes those load's so well it becomes irrelevant.
I'd be happy to be corrected .
Good job on those videos , been following you for a while now.
a wonderfully complex combination of simple principles. very clever
The beauty of this solution is its simplicity. I wonder why no one else thought of this. In recent videos of the Project One, I can see that there's no body roll and it doesn't feel bone cracking hard either, seems to glide over the rough bumpy tarmac of the Nurburgring.
Great presentation, so nice to have an explanation that's clear and short, well done.
How incredibly complex! Good explanation. I always wondered how these set ups worked.
Tbh it's more simple but it's more complicated to come up with such a simplified system.
This is truly genius design
At 6:04, wouldn't one have two separate shafts ? Not doing so would effectively relocate/create a "second" rocker pivot point that would, in effect, "lock the rocker on heave and compression? The horizontal damper would then be rendered useless if that was a single shaft! Additionally, looking at the gold mounting base, there are two sets of damper adjustments. High/low speed adjusters- I'm thinking separate left/right adjusters.
As always, thank you for the awesome explanation! I'm loving these videos as a keen auto engineering student!
Can you do a video on a FRIC F1 suspension system works? Specifically with Mercedes? How does the system control heave and pitch?
Just found these videos and love the wealth of info! subbed!
Yeap. Interested to see the breakdown of geometry once the steering arms are in place. A SolidWorks type model an animation would be superb.
This was the first of your videos that I've watched and it was excellent! Keep it up.
The double-jointed outboard links are known as virtual ball joints and are designed to move the effective pivot point further outboard to reduce kingpin inclination, kingpin offset and scrub radius.
This type of heave spring combined with laterally connected antiroll-mechanism is relatively common in road cars. The Citroen hydropneumatic suspension operates like that. Those hydraulic suspension spheres are laterally interconnected making them work like a heave spring. The hydraulic pipe offers some amount of roll damping. And there are lateral antiroll-bars front and rear to prevent the car from tipping over because of the lateral interconnection.
About that separation of roll motion and single wheel bump motion. Aren't those two motions actually same motion: Wheels moving opposite directions in relation to each other. No matter how I look at that suspension mechanism, every time the left and right side wheels move in opposite directions in relation to each other, that motion is resisted by the roll spring and heave spring working in parallel. When looking at the rear suspension 3:05 if the left side rocker is rotated clockwice, that motion is resisted by both heave and roll spring because of how those springs are connected to the rocker at the right side.
It would be interesting to see modern vehicle where the antiroll-bar is not connected between lateral pair of wheels, but is instead connected between longitudal side-pair of wheels. One for left side and one for right side. Citroen 2CV had this style roll spring (those coil springs inside suspension tubes, during roll or heave motion. During pitch they behave in different way), those spring were just very soft and because of that 2CV leans so much. The British Hydragas/hydrolastic was simple hydraulic version of that. LLTD could be simplified to simple geometrical leverage calculations, and ground shape would have no effect on lltd.
I think with those front suspension arms, mercedes has tried to create centrepoint steering geometry using virtual geometries to remove KPI and offset. At least from pictures, it looks like the n-lines of the suspension linkages intersect somewhere around the center plane of the wheels, so the instantaneuous screw axis of the hub should be somewhere around the center of the wheel.
Hi there! Great explanation 👏🏽. Do you know how could potenciometers be applied on the roll damper? Do they need to have two linear potenciometers one for each spring or can it be just one since the springs will have the same symmetric movement?
5:15
...Upper roll spring cant strech... not retained...so used 2...
FEEDBACK FROM AUDIENCE REQUESTED
If a retainer was used could this pice be a single spring?
Hope the new (years old) job is happy. Cheers.
Wish you could work out some kind of deal for a "limited disclosure agreement " of non Co. data or analytics . If nothing else, that you may inspire your replacement who is only 7 years old now.
GREAT explanation and illustration!
Shouldn't damping be more soft on single wheel bumps, for more traction on the other wheels ????
Otherwise the car would tilt and I think you would lose traction on two or more of the other wheels.....
By separating the A-arms, they will be getting a 'virtual pivot point' for the steering. This brings the ball joints inboard, which makes room for a better brakes package. I.e. Brings it inboard too which allows for better cooling. Look how inboard the calipers are!
So as some that might want to make this at home with parts you can buy what if you make a x with the shocks and leave the top parallel shock off. Or if a do that would I still need a top shock alone with the x patter on the bell cranks to get the same effects. I'm also guessing I'm not going to need springs with high tensile strength like I would in other set ups. Kinda would like to know how I could go about calculating what springs I need for a weight of the vihicle in a set up like this or the one I described.
Check out the wiggle in the front left pushrod at 7:04 Must be seriously strong!
Kyle! there is something interesthing abou the rear arms as well!
There is an extra rear suspension arm located between the rear arms, a 5th connection. It looks interesting as it seems, if you mentalize the suspension compression motion, as it has a shorter length when compared to the inferior arms, when the suspension gets compressed during heavy cornering centre roll, that arm tends to modify the toe angles accordilgly to the chassis rolling, opening it when compressed, closing it when lifted... Check this video at 7:30 and onwards! please! th-cam.com/video/EzV_1hF4pxM/w-d-xo.html
Also, it seems the engine doesn't have the same exhaust manifold the F1 car has. The F1 uses a shorter ram lenght exhaust duct and it makes sense for a road car since spooling time won't be a problem to it given it's electric motor in the compressor and bigger batteries. this buffs the lower rev area. I bet it doesn't have the same cam profile as well. And i see a stressed member chassis which means this car is going to be stiff and light. Only a few car manufacturers make use of the gearbox case as stressed member. Usualy it only suits racing cars.
The koenigsegg looks like it uses somthing similar. Really great video!
Theirs is different. It's used for anti-squat in Koeniggsegg's application
@Amarjit Singh to the Koenigsegg, yes
Great explanation sir!
Very great explanation to those complex design, thanks!
can you do one on the aston martin one-77 since the shocks are in a very weird position in front of the engine on that pushrod like setup, one on the aventador would be sick too, great video
Would a setup like this be less needed when using sprung areo?
If you haven't already you should check out greenteam stuttgart's solution to the independent roll and heave spring/dampers. Pretty neat solution that doesn't require a through shock or two springs. On the topic of FSAE Suspension I'd love to see you do a video on AMZ's active damping hydraulically mode separated suspension, a bit of a mind bender.
Hadn't seen it, but pretty neat solution! Hadn't seen the AMZ one either (I haven't been keeping up well with FS lately!) but it looks like a slightly more elegant version of what Monash was running a few years back. I really love seeing these types of suspension out on FS cars.
KYLE.ENGINEERS yeah similar to monash's solution...leave it to the European FS teams to take it to the extreme. I'm on the UQ team and two of our previous cars (2014 & 2016) employed purely mechanical mode separation by using the under tray tunnels as longitudinal beams transmit roll load to a single ARB. Soft warp hydraulic mode separation would probably be ideal for off-road racecars like yours, lots of compliance for all the bumps.
could you guys share a link or image to it?
AMZ's suspension system isn't an active one, it's all passive ;-) You also have to mention Rennstall Esslingen's roll heave system in their last two cars I think, but they have one heave damper and two roll dampers and also High-Octane Motorsports roll-heave system in their 2015 car. They only had one roll damper without an spring, but included an anti roll bar as roll spring.
@flealr92: you can find a lot pictures on their social media sites :)
Currently I work on my master's thesis which is about design new type of suspension for lmp1 car based on this idea. It is a lot o fun So far. Let's See what willl be the outcome.
I swear, i was thinking about this type suspension few years, since Koeningsegg was fighting with suspension squat in a quite complicated way.
The sad realisation that with 7 billion people in the world, someone somewhere will have thought of your idea and acted on it first
@@dsdy1205 100% yes!
So.... compared to a conventional setup with an anti-roll bar, more stiff on one wheel bumps(two springs and dampers active) and softer on roll, pitch and weight(one spring and one damper active). Hm.... Need furthur clarification on how much spring tension and damping is desirable on each modes.
This is such a beautiful design in its simplicity. It's ingenius, but also makes me wonder why I've never thought of it before.
Thanks for the video!
thats a really cool system, so its a very compact and fully adjustable and dampened anti roll system
Great Vid Kyle, please make an update on the AM-RB final edition, they changed the whole undertray of the car.
Don't worry, it's coming!
And the rear too (including exhaust placement)
Very nice illustration By you!
Well done as usual sir
I might have missed it in the video but how das Mercedes want to adjust the roll independently? I haven't seen an ARB so far.
That was damn interesting
Excellent explanation, Kyle ! :)
German (over) Engineering..
At it's finest.
Hardly over engineering. If anything it simplifies a lot in a very clever way.
This German engineering bullshit is a dead meme, look at the average rank of German brands on the reliability index www.reliabilityindex.com/manufacturer
Ladies and Gentlemen,
this is not the Index how reliable a brand is but how much a car owner of a certain brand cares about his car and therefore shows how much it is maintained...
Well these are simple kinetic chains...
Did you even read what you posted? The reliability ratings of German cars are still GOOD. It says so in the link which you posted.
Furthermore, there are some brands listed here which sell in such low volume numbers you have to wonder how these cars are ranked and graded. Daihatsu? Chevrolet? Suzuki? These are low volume cars in European markets. In fact Daihatsu is not even sold in Europe anymore. They pulled out due to low sales.
The reality is that German cars are high quality, well-made, durable and reliable. I speak from experience. Every brand has cars which are less reliable than their bread and butter products. The whole Porsche lineup for example may be very reliable and low maintenance - except for say the Cayenne. The Cayenne thus brings the whole brand down on a "reliability index."
Worst car I've ever owned was a Nissan Cefiro. Do you see me going around hating on Nissan because of one bad car?
Does a car windshield produce downforce or is it even possible for it to do so?
Ratz no,it only contributes to drag.
The comment above mine is wrong. Of course it produces downforce given it's shaped like a giant wing. It also produces drag which is a byproduct of downforce.
the statement above mine is also wrong, since a windshield is not shaped like a wing at all. But a windshield will partially act like a spoiler as it directs the airflow upwards. And therefore the air will press down on the windshield
Anyone who's ever seen a windshield would know it's mostly flat and raked like a spoiler.
Actually, I believe it will provide some amount of lift. As air flows over it and back down over the rear of the car, the movement of the air will cause a low pressure area above the car. If this isn't compensated for by providing a similar affect under the car, it will have a net upwards force on the vehicle. Airplane wings provide lift using this concept, having a curved top that causes the air to move without providing to much drag, causing a low pressure area on top, and a flat bottom that leaves the air as undisturbed as possible to keep the pressure as high as possible. Wings on racecars are similar, but turned upside down, and are far more aggressively shaped because drag is a much smaller issue when downforce is so beneficial. I believe the tops of them are curved because it can provide a ram air effect, raising the air pressure on top at the expense of very high drag. The most important part of them is the bottom though, where the air is made to be at the lowest pressure possible over the largest surface area possible.
hejj kyle nice vid. Has this system the same idea as the triplex suspension of königsegg?
Sort of. The konigsegg also makes the car roll as it goes into a corner. Turn left, the left side lowers
What other cars have used this type of suspension? Is there a name for it that I can google?
Ive seen a similar thing on Formula-Vee but its for heave only and its to encourage roll. Not minimize it.
Where's the aero analysis for the project one? Have you deleted it because I can't find it on your channel.
so apart from the shocks the front its basically a 1990's ATTS Honda prelude
How much harder would that be to do maintenance/repairs on?
Is there any way this could be adapted to off-road or rally racing?
The triplex system seems to be doing the same job, but in a more Gen 1 sort of way. This is super complex though.
Can you make a video on how venturi tunnels work,and how would a diffuser just behind the front splitter work.
he has done that already
i didn't just like it , i loved it ...,pls make more similar videos
Good lord that's brilliant!
Thats an awesome design, great explanation.
Additionally, can you do a comparison between this, standard "T-bar" third-element suspension, and Koenigsegg's triplex suspension?
Technical name for it is "full floater suspension" ....Trek bikes use a similar setup on a few of their models
The connected bell crank set up is genius. It is ant roll without a roll bar. It takes the preload off the wheel that isn't under pressure from the roll
do you have anything on roll centers?
I thought braking would put pressure on the front wheels and acceleration put pressure on the rear wheels lifting the front up?
SO they copied a Zero-Roll suspension setup off a 1984 Formula Vee?
Can you take a look at "Formula X" from project cars 2?
Also why is compliance from the suspension such a problem in F1 but compliance from the tires fine?
Compliance from the tires is not fine, there is just nothing they can do about it since it's heavily regulated, the same for everyone and supplied to them so the suspension has to be designed around it. Thus you get things like mass dampers and inerters.
Im just gonna drop out and watch your videos, thanks.
So how good will the ride of this car be on the road? Will it have multiple suspension settings?
It will have multiple suspension settings AND ride heights. Baller ;)
Great work
The prognostication, from 5 years ago, that 'grip is likely going to be obscenely good', appears to have been verified as True, given that the real, road-going (well, if you have USD 2.7m to spend..) AMG ONE, utterly smashed the road legal Nurburgring lap record, last December (ie 2022)
Aston Martin AeroBlade analysis please
Couldn't they hypothetically use a traditional roll bar as the roll springing mechanism and then only require a typical damper attached to the roll bell cranks?
can one say that this is independent suspension then? I would think by lookin at this that a bump felt by one wheel could disturb the other due to the higher damper.
The diagonal spring and shock are moved during roll only
"Chazi"
Whut?
Shazzy 😊
Ozzie.
It's chah sis
the problem is with that roll system. corner one way and the damper compress then rebound on return yet corner the other direction the damper droops then compresses on return..since there is one damper on roll...how would they set that up? mechanically speaking if compression and rebound are set at different loads...having one damper handling two opposite characters would be really complicated
When controlling roll independent from heave, compression and rebound can have the same damping.
Thanks Kyle.
In single wheel bump, I think that is too stiff.
Because each can support to load on its own, but they operate in parallel.
How would you adjust ride height with this kind of setup? Anybody please
Simple, adjust the preload on the heave spring! Or alternatively you could increase the pressure inside the heave damper, which will increase the shaft force.
Thanks! It was very good! but why in this car we don't have an inerter or complicated suspension like on the current Mercedes f1 car? Maybe this suspension is good for this car but personally, I don't see this so complicated! Maybe this is all rubbish, but, it's my opinion!
Why multilink suspension is unexpected on race-based car? Multilink provides better control, doesn't it?
Note that the ONE was a prototype for a road car, not a race car. If you can call a car than, now it may be bought, costs almost USD 3 million, can fairly be called a 'road car'!
48-0 likes-dislikes ratio, not bad
350-0 Now, pretty good eh! Although now I've said that someone is almost certainly going to dislike it...
Krzysztof Dolecki make it 352-0
edit: number typo
408... working on a record? Think you've found an audience niche here Kyle.
470-0 !
2068 : 45
Thats a pretty nice Schazzy
Comparing this car's aerodynamics to that of the P1 doesn't seem to be giving this car enough credit, one look at the interior will tell you that this car is a lot lower than just about anything but the Valkyrie and maybe the probe 16. It seems like it's aerodynamically in between the Valkyrie and the more conventional hyper cars.
I have to wonder if the fairly recumbent driving position increases the risk of dozing off on long drives. Also I've never been this interested in fuel economy figures for a hypercar before.
hmm so 3 springs instead of 2?
very nice,Thank you
No double a-arms in the back? How is that a revelation? My 1996 C220 has a 5-link rear suspension. Mercedes only recently downgraded to double a-arms on their rear suspensions.
Bellcrank suspension with no subframe...
believe or not but toyota has design and manufactured similar suspension on the front suspension,its called superstrut suspension and it can changes caster during steering change and i believe reduces torque steer,it was use in corolla ae111 levin bzr
The potato Party pooper well that's nice :O
They did this superstrut on the Celica GT 4. This is not at all similar to the mercedes suspension... But it does indeed reduce torque steer by giving a lower scrub radius for example.
Not to mention; adding obscene rebuild cost once the figure 8 links wear out.. :-)
👍 7:50 Check, my A5 has that setup.
Doesn't Koenigsegg have something similar, even if it's less advanced?
Mattias Filander their design is pretty different, basically just a third damper between the two rear wheels tuned to resist squat more than bump.
F1 have L, R and heave damper.
This clever design got rid of a third spring yet, able to have the function of 3.
KEEP MAKING THESE OMG
Great! Thanks!
Well... fancy setup of 50 year old suspension technology from Citroën 2cv
You can designer car engineer... My dream is designer car :)
Awesome！
The thing I’ve never understood about these types of suspension is wouldn’t the assymetric setup be more effective to one side than the other? or is that counterbalanced with weight distribution?
The car actually squats in front under braking..
Why not just go active? I love physical suspension design and kinematics but it’s all a bit Stone Age.
Springs. Really?
If you had an active cartoon of how it worked in motion it would be a lot easier to understand but I know thats expecting a lot and not that easy to produce but I didn't understand anything that was said as interesting as it is. I guess I'm just a dummy. Thanks anyway
or like the fucking gl suspension w/ the independent arm thing i'm just saying it not brand new
Oh the chazy...
Here is not a direction or device action, only where your finger is pointing. I found it quit annoying after the 7th time you employed this term. Try compression, extension, stationary, relaxed or immobile as the the likes of a non-car subject would mindlessly watch. DK, ASE master tech since 78, retired.