time table : @2:10 load vs grip @4:23 spring rate @6:10 important note about cornering @9:39 anti roll bars @10:58 anti-roll bars effects on over-steering and under-steering @12:06 anti-roll bars and the overall balance of the car @15:15 under-steer and over-steer cheat sheets @16:30 over steer and under steer set up and how wide the wheels are
This series is simply IN-FREAKING-CREDIBLE! Thank you so very much for putting such effort into it! It would be great if you could continue into aero, shock absorbers wizardry, chassis rigidity and so on. 😇
On this topic: Your videos are the best comprehensible for me - by far! Clear definitions! Very good graphic models that show what you talk about. No shitty music! I love it
I'm studying automotive engineering, I've been passionate about this subject since my childhood. Cane here to clarify some of the basic concepts. This was extremely helpful. Kindly make such videos on as many topics as possible focusing on the performance side. Thanks a lot.
Anti-pitch bars are useful but difficult to engineer unlike anti-roll bars. The main reasons are the anti-pitch bar will need to be mounted under the car's chassis as it needs to long enough to reach between the front and rear suspension arms. A tube or bar of sufficient length would be much lower in rate so it needs to have short arms and be very thick. It would be a heavy addition to both right and left sides of the car. There are ways around this but too lengthy for this post. The advantage of anti-pitch bars is you can soften your spring rates to increase grip while maintaining overall wheel rates of the entire sprung weight system. In an ideal situation, yes you would want to utilize both anti-roll bars and anti-pitch bars. Active suspension can achive this at essentially zero wheel rate with perfect anti-roll and anti-pitch coupling.
I recently cancelled the purchase of sway bars because I learned that they actually decrease the traction on cars with independent suspensions. My question is, why wouldnt I remove the sway bar completely?
@@MW-qo8hw Anti-roll bars decrease maximum traction, yes, but that doesn't mean that they aren't useful. Maximum traction is only really the most important thing in steady state cornering (like long sweeping sections). But during transient motions, you want to prioritise keeping the car level, as this will allow you to begin rotating the car faster, even if the absolute peak grip will be reduced. Running no anti roll bars at all will make the car really sloppy on turn-in and fast directional changes if you springs are soft. Car setup is all about compromise. Are you going to be driving on a really fast race track with lots of tight, technical sections that require you to be agile through the corners? If you are, go get some anti roll bars. Are you going to be just using it on the mountain roads or in the street where you're not driving too quickly and the cornering radii are generally going to be much higher? Stiff anti rollbars are gonna suck, not because of the changes in handling dynamics (you'll feel the difference but it's not going to be too significant) but because it's gonna be bumpy as hell.
Anti pitch is generally controlled.by rebound damion on the rear in inbound damping on the front. Keeping the weight balanced during weight transfer is key. Lateral (roll) grip must be weighed against braking/acceleration (pitch) which is why sway bar and damper settings must be changed together
@@Not_A_Cat Here is the easiest method to achieve a well balanced and consistent balanced car. General guidelines. 1. Never use higher-order forces to compensate for incorrect lower-order forces. 2. Never use lower-order forces to compensate for incorrect higher-order forces. 3. Less force is generally better than higher forces. 4. There are fewer and smaller trade-offs when dealing with smaller forces. A lighter, lower and wider car will have smaller forces to deal with using spring rates, anti-roll bars, shock rates, and aero. 1st order forces: Static weight distribution and Center of gravity height. 2nd order forces: Jacking forces, unsprung forces, and sprung forces as well as aero. 3rd order forces: Shock dampening and gyroscopic forces. 4th order forces: Generally only achievable with active suspension and active aero. Such as velocity dependant damping rates and g-force dependant aero.
@@WhitentonMike I don’t know at all but u sound like a freaking genius, I like learning about this type of stuff. Is there a place or school you would recommend going to around the Houston area
I've watched all of this series. They are so incredibly well made! Thanks so much for the help and the amount of time that was put into these! Your Mercedes LS to modern videos are what got me started with your channel
Towards the end of the video, it shows how much your front spring bends, and doesn't just go up and down, just like your rear springs, Just goes to show how all the "Keyboard experts" were telling you that "you must use coilovers", I think that proves perfectly that your rear suspension may not be perfect, but obviously works really well. I for one have really enjoyed all your videos.
I really love these educational videos about automotive engineering. You should do more and title them as such, as a suggestion. That way, they'd get way more views and the RUclips search engine would categorize them that way. These are really great. Keep up the good work! Look forward to more in your channel.
One of the best engineering videos. One thing I could not understand, hope you explain. This diagram: 13:35 . You basically said the front (with anti-roll bar) has more weight transfer than the rear (without anti-roll bar). Wouldn't it be the other way around as that is what anti-roll bars are for (to stop body roll and weight transfer)?
I'm a year late but. Every action has an equal and opposite reaction yeah? ARBs resist lateral weight transfer, therefore the axle that resists the most also bears the most force, which reduces traction, hence why you can use them to tune over/understeer.
@@Taverius bro can you explain? I dont understand wtf is going on, the anti roll bar is to stop this weight imbalance right? then how is it adding onto it?????
Weight distribution is not affected by ARB. ARB only changes body roll, remember force is energy that cannot be destroyed. I wonder what happens if wheels are set to positive camber and body roll cancels inside tire camber, does it increase or decrease axle lateral force. I need a tire coefficient of grip versus positive camber chart.
Thanks for this video! It helped clear up some questions I've had for a while about sway bars & spring preload. The way you presented this information was really clear, and the diagrams were simple, but very effective. Really great job on this video!
Great video. My previous car was a Citroen which had an hydraulic (edit: hydropneumatic) suspension. Now I drive a BMW and it is superior on every aspect, except for the suspension! It really was very good. Soft and no body roll. The Beemer also has hardly any body roll but it’s much stiffer.
@@Conservator. my mum has a Citroen C1 . Hydro Pneumatic. Hydro - of water (Latin). Pneumatic means. Well, involving air, right ? Sure, those mass produced suspension systems might be well researched. I watched this series of videos. He did not really mention, Stress transfer front to back, that much. It's interesting to hear about. The Torque Bars, he covered many of the concepts well. Hopefully soon, I will break out my BMX. He said, don't worry if you have, hydraulic suspension. I used to work with hydraulic arms, actually.
@@MrRobertFarr The hydro-pneumatic suspension works with oil and air. As far as I know, Citroen only fitted their hydro-pneumatic suspension (hps) on their larger cars (C5 and C6). The C1 has a conventional suspension and they’ve stopped using hps at all 5 or 10 years ago (unfortunately).
@@Conservator. Ah sure The Citroen Xantia maybe. My friend had a Citroen Xantia. Well, I read up about Citroen, I believe they were taken over by Peugeot. Did you ever see the French movie called : Taxi ?
Awesome video !!!! You are helping me so much. I love racing sims and just started tracking my e46 m3 this year Your videos are really helping me out. Also I like learning new things at a fairly deep level and your videos are perfect for that. I"m really digging your channel. You are doing a great job on these videos. They're extremely well put together. Congrats on the quality content, and thanks. Give yourself a pat on the back :)
At 6:00 he says that if you have half as much ground clearance, you will have to double the spring rate. That's true if you only use springs to resolve the settings. You could dial in anti-dive and anti-squat, and keep the spring rates lower.
The reason I'm going for stiffer springs over thicker bar is because of one wheel bump situations (country road scenerio) sometimes in these cases it's better to look at Springs to maintain the indepent operation where it's needed
This is the best explanation I've found online. It says sway bars are to prevent roll, but doesn't say why roll is bad or how much is okay. Loads are more balanced without a bar, so adding a bar makes that end unbalanced and reduces grip at that end. So while adding a bar to front or back can reduce grip at that end and change oversteer/understeer, it doesn't improve cornering g load. I'm guessing the bar is needed to prevent the outside suspension from bottoming. Also, the camber change reduces grip, so beyond a certain roll angle, total grip will start to reduce. So there is some roll stiffness that gives optimum cornering g for that end of the car. Does this make sense?
Yes, it was helpful in that, I am lying here exhausted and need something to keep me sane, without too much effort for my body. It will help me explain what, I instinctively know is wrong with a motorcycle suspension with four springs. The issue of front suspension on a bicycle and the absence of anti roll bars there and on a motorcycle. I wonder what the horizontal suspension or springs were, under the car is, is that a form of anti roll bar ?
On 12:50 we are adding another sway bar on the front axle which means we are increasing stiffness in the front so the roll will be less with the load difference between outside and inside wheel on the front. But in the video the whole explanation was reverse between front and rear axle. Can anyone tell me if I'm wrong and where or there is a little mistake on the video. Thanks in advance!
8:40 every suspension kit I've seen that has separate spring perch collars and lower collar says that you should NOT be adjusting ride height with the spring preload perches. The shock AND spring assembly should be spun up or down into the lower mount brackets for height adjustment.
You are correct, when you have “divorced” dampers. Some dampers only have the upper spring perch for adjustment, but the manufacturer has already built in the amount of ride height adjustment for you, based on the spring length and damper travel characteristics.
I just finishing refreshing suspension Sway links, bushings, upper control arms, lower control arms, and outer ties rod Did it all myself, I have b8 and lowering springs cmg
It also depends on the tire compound and width. Caster and camber are other factors which greatly effect ride and grip. Polyurethane bushings on sway bars are a must for track use. Dont cut your springs to achieve a lowered look. When a car doesn't turn it's called pushing and when it's oversteering it's called loose front wheel drive cars are prone to understeer and push rear wheel drive cars are prone to loose and the back end stepping out that can be remedied with simple tire pressure adjustments. Bottom line is if you don't have the money to do it right don't waste your time or your cash on some cheap half ass suspension because you're just going to end up stuffin your car and your insurance isnt going to cover it at the track. it costs money to go racing!
Your formula for Wheel Rate and Spring Rate is incorrect. It is Wheel Rate = Sprint Rate x (D1/D2)^2 The reason is you are not only changing the force but the distances traveled. Remember that a Rate is both Force and Distance so you need to multiply the lever arm ratio twice. So a lever arm ration of 0.5 would result in the force difference of 50% and the distance traveled of 50% or a rate ratio of 25%.
Also take in to account your sprung vs unsprung weight. Damping is more important than overall spring rates, and geometry can be altered to maximize the characteristics of any given dampin/spring combination. The whole science is relativity, one change requires 4 more changes to make the geometry work on a given road surface.
Have you already done a video on dampers as mention in this vid? Couldn’t find anything… aside: superb video on springs and ARBs, excellent explanation! 👍🏼
From my understanding (don't know if it's correct or not) , by having an anti-roll of whatever stiffness, it's limit the overall body roll so you can keep the overall car CoG close to it's ideal spot in expense of taking out the grip of the tyre (either front or rear) as the anti-roll bar always unload the inside tyre more than the car should and load the outside tyre more than it should under weight transfer. (Edit) I also think anti-roll bar does help with the car than run an underbody aerodynamic downforce where the ride height are crucial to keep the ground effect work efficiently.
If you add stiffer anti roll bars at both the front and rear then yes, they should only reduce body roll and have no effect on the balance of the car. If you reduce body roll you do reduce weight transfer by a bit but the bigger benefit of less body roll is you can run your car lower which reduces weight transfer further. So yeh anti-roll bars have both uses, reducing body roll and fine tuning the cars balance.
@@xfmotorsports sorry one more thing- I think saying that ARB is a device to get a certain balance off the car ( that is actually what gives that extra drivers confidence and ultimately speed ) and the less off ARB you can get away with- the better , is important so people would lose this misconception about them as one off the most important "speed" mods.
Boy, so much info! You had said to adj. the the "top" of the Coilover @ the spanner nut/s and not the bottom where the male female threads @ the shock tube is, as far as ride height goes, I thought it was the other way around ? Plz clarify this... BTW the Video is awesome. Ps. I would want to go with front soft and rear stiff w/ a front wheel Dr car?
Okay so the basics are explained pretty well **BUT**, I don't know if you are a race engineer or a hobbyist, but you're not right about the application of the anti-roll bar. If you move the antiroll bar from rear to front it will increase the roll at the back and decrease the roll at the front. And when you have an antiroll bar it means that it will reduce weight transfer, in your situation is increases the weight transfer, so you have an anti anti-roll bar? Then the understeer oversteer part... There is just 1 place where you will have understeer or oversteer that you can improve with the anti-roll bar, at the apex (initiation is more dampers). When you have understeer you want to decrease front weight transfer, so you stiffer the front antiroll bar or increase rear weighttransfer by softer the rear. When you have oversteer it is the exact opposite way. The springs are correct but it is more about the braking area. I hoped I helped you out and hope you understand I had to make this clear as I'm a race engineer in the European GT4 .
Not true Stiffer front roll bar gives you understeer. Its commonly known if you ask any time attack competitor or even search it online. I've played around with roll bar settings on quiet a few cars and they make a pretty significant difference. You can try it yourself, just remove the sway bar end link on your front suspension. It will start to oversteer more.
I agree with only "And when you have an antiroll bar it means that it will reduce weight transfer, in your situation is increases the weight transfer, so you have an anti anti-roll bar?"
I agree with MTYD23 that if you have stronger roll bar at the front car will be more understeer. Same in opposite way. You can find more in channel Engineering Explained. You can find in racing set up videos like How to set-up a racecar? By Tom Coronel, Suzuka Japan WTCC 2013 This is also tested on the track. So please do not share this incorrect information.
1. 'If you move the antiroll bar from rear to front it will increase the roll at the back and decrease the roll at the front.' I mostly agree with the statement above. However, assuming the chassis of the car is reasonably stiff, this effect is relatively minimal. 2. I am pretty sure that SK8215 is right. If you increase the stiffness of front anti-roll bars (or front suspension), the car tends to understeer. Please refer to the explanation below. 3. 'When you have an antiroll bar it means that it will reduce weight transfer.' This is also correct **BUT** it applies to the opposite end only. NOT the same end! For example, a front anti-roll bar reduces OVERALL weight transfer at the expense of increase front weight transfer. Thus, rear weight transfer is reduced. Please correct me if I am wrong.
excellent video thank u very much,the animation is perfect,just a quastion, in case u would only put stiffer springs at the front(and leave the antiroll bars front and rear as it was on the initial set up)how would the weight distributed in that scenario?
Was playing Forza and wanted to tune little bit even though its a video game, it has somewhat accurate simulation of physics that i can take from real life and apply them to the cars in the game and get the desired outcome. (Forza Horizon 5 is Simulation/Arcade Racer not that extremally accurate compare to other even more in-depth hardcore sim racers out there with pages of adjustments you can tweak) Feels odd sometimes looking up irl tuning guides and applying them to car`s in the game, but it gives me more incentive to learn about cars and how they work on a fundamentally level.
hi there, really appreciate your video, I love it! So if I lower my suspension by using after market ones, how should I change my alignment? Is the OEM alignment still valid? And if I want to make the steering sharper with quicker responsiveness, should I decrease the toe or chamber?
i cant understand that at15:46 , why do we soften the front springs to fix understeer, i thought it will further uneven the load between two front wheel, which will reduce the total front grip
Great video! one of the best I've ever seen about the matter, But I didn't understand the anti-roll bar exemple. I always thought that the ARB worked transfering part of the forces applied on the outside wheel to inside wheel, thus reducing the roll effect. What I get from your example it works on the opposite way, increasing the forces on the outside wheel. Is this so?
+1 on this, that confused me. I thought by adding the rollbar, the RHS would get -150kg rather than +150kg, since the torque on the roll-bar would counteract the weight shift on the RHS of the car.
I always find it a bit odd that they use the unit of 'kg/mm' , kg is a unit of mass. It would make more sense to use a unit of force because that's really want they mean by 1kg, they mean 1kg under earth's gravity. In any case, I LOVE your videos, keep it up !
It's easier to calculate since mass of your car is in kg and material density of the spring you're using is in kg/m3. Why transfer it to newtons and back when you can make your life simpler, just make sure that you put diferent suspension if you're planning to go on the moon
Very informative! There's one thing I don't understand when you put the rear seat bar to the front wouldn't the car roll more in the rear and less in the front?
The front and rear cant roll independently of each other unless the cars chassis is really wobbly. Usually chassis only flexes less than a degree so the front and rear body roll is more or less the same.
This can't be correct. You even say in the video that you don't want your sway bars to be too different front and rear... Now you're saying it doesn't matter because of chassis stiffness? In a dynamic situation, like acelleration, weight shifts reaward and I'm 100% positive the rear can roll more than the front in this situation. I've seen the pics to prove it (rwd with no rear sways).
The reason you don't want extremely different sway bars front and rear is to keep load even otherwise you can end up in a situation with one wheel lifting off the ground (inside tire reaching 0 load). The situation your talking about is pitching and rolling at the same time like under acceleration out of a corner. That still does not make the front and rear roll differently. The roll centers can be different front and rear in which case the car rolls around an inclined or declined axis but the roll is still the same front and rear
SK8215 I disagree with that and you even contradict yourself in your own rebuttal by saying the car can roll at different rates but roll will be the same f:r on the outside tires. That's just not true if more weight is shifting rearward due to acceleration and the outside front tire is unloading... the inside rear tire will squat and roll more than the inside front tire when accelerating out of a turn.
That's not what I said at all. Read the comment again. Roll is measured by the amount your cars body leans towards one side from horizontal. If your accelerating the car pitches back at the same time as well. That does not make the rear roll more than the front. Its just pitching and rolling at the same time.
Could u explaine the rebound and bump can u change over and understeer with the rebound and bump and is there a formula like having a 50 50 weight distribution the car weight 2000 devide 2000by 4 is 500 each wheel so i put my springs at 500 but how could u calculate the rebound and bump vs the springs its for a race game simulation great vid btw
What is the role of anti-roll bar bushings? What happen when they are worn? Everywhere I still read only squeak as related problem but nothing about drive sensations. My car start with some squeaks in wet days and now, after some years, is a little unstable. I've new shocks and springs but the car have unpredictible body roll when I turn. I need to constantly adjust the trajectory because I feel all the car heaviness on turns like unflated tyres or bad shocks (but they are new now). The roll transfer when I turn the steering wheel is not progressive, it happen suddenly like heavy iron ball move on a side beyond a certain threshold This problem could be related to worn stabilizer bar bushings?
Does the added weight of suspension become prohibitive at some point . . . Ergo . . . most go-carts and bicycles typify this response I do believe ! ! !
hi good morning, I have a question, I have a 2011 wrx sti sedan and I am running tein enduro pro plus macpherson style struts, paired with tein spec c lowering springs, my car handles like crap, very bouncy and wobbly, i have whiteline endlinks to install, can you advice me what might be going wrong?
so whats the best bang for the buck suspension upgrades for a 2011 2 door civic? i live in a very hilly area and lotsa curves so i want better handling but cant push it to limits to see if my car understeers or oversteers cuz i will end up crashing in the side of the hill or over the cliff? does a stock civic under or oversteer typically? bigger stiffer rear swaybar combined with fatter front tires would be one possible setup , right?
You stated that adjusting the top lock washers on the coil overs is where you adjust preload and ride height.. Can you explain yo me how this adjusts ride height over the bottom coil over body adjustment? It was always under my understanding that the top was only for preload and never for ride height... Very good video by the way
The cars weight can only compresses the spring by a certain amount so adding preload wouldn't compress the spring further, it just lifts the car higher. The only time it actually compresses the spring is when the suspension is at full extension. The lower setting will also change ride height but your changing the point at which your suspension bottoms out every time you change that. Without proper bottom out settings the suspension could go past its normal travel range, so the tires could be hitting the top of the fender or the cars bodywork scraping the floor everytime it hits a bump too hard. Ideally the bump rubber over the damper is supposed to stop that from happening if the length of the coilover is set properly.
@@xfmotorsports good job on those videos, just would like to point out about corner balancing, what you said in the video end comment here- when you do it with spring preload that's when you are changing the travel ( more preload will result in cars weight compressing the spring less , shorter distance) , and will have less effect on transferring weight between corners , plus it will vary a lot depending on your springrates. That's why me and people I've worked in the field with usually use mostly the hight adjustment perch for corner balancing and preload for damper travel ( or otherwise - a combination of both). Good job again. And impressive self control on some off the comments obove .
It would depend on the design of the coil-over. In most common designs i.e "BC suspension" (with separate ride height and preload) range lowering or raising from the bottom will not change the damper piston stroke position. The whole suspension unit would be static in its own right and only be lowered or raised via the bottom cup. If it only had a single adjustment point "spring perch". It would do both simultaneously. If lowering excessively it would reduce compression damper stroke plus on full droop ( when the car is jacked up ) your spring would be unsupported and rattle so they introduce helper springs. I am not familiar with what's fitted in the car but the above rings true for most suspensions kits on the market. This kit may well act as stated.
just a question: @13:34 shouldn't it be +150kg on both the front tires? Or even +300kg on both, because you've got 2 sway bars instead of one, but that is less important than the first question. I mean, as you said, the sway bar will try to counter balance the forces from the roll movement of the vehicle, so it should add an equal amount of force on both tires, not adding to one and subtracting to the other, right? And i think it's also because if the total weight of the car is 2000kg, it means that in a static situation, the sum of the normal force on all 4 tires should be 2000kg, but under roll you should consider the force given by the sway bar(s), so the sum of the normal force on all 4 tires should be ABOVE 2000kg. It's kinda confusing me, i don't know if i'm correct or not, so please read this. Also, i must confess it's the 6th or 7th time i've watched this particular video, and i even watched more than twice all the other vids on your channel, you're one of my favorite channels, so thank you for all your work!
Hey, load can't be added on both front tires using an anti roll bar. Also, the example is assuming a car is going through a corner and the forces on the chassis are only lateral (no longitude forces), so it will transfer weight side to side but there's no weight transfer rear to front. If you add up the values from both front tires they are 1000kg before and after. They only time that will change is under braking or acceleration (when weight transfers longitudinally). Anti roll bars and spring rates will only transfer loads corner to corner but they can't change the weight distribution entirely. The only time you will get anything above 2000kg or additional added load over one axle is if there is downforce or some external force on the car. Hope it makes sense
Someone please explain to me. I feel like the section about adjusting the coilovers at the preload is wrong. Wouldn't you loose suspension travel? Also if you run helper springs or progressive springs it would affect the spring rates. (Heck even linear springs probably aren't completely linear). Adjusting the height should still allow you to adjust the weights and would effectively compress the springs more where weight was moved to, but without sacrifing travel/droop. Please help me understand.
A question about corner balance. if I change the spring rate of the car but maintaned stock ride height, is my car balanced the same as before? I dont understand why increasing the preload would put more weight to the car, shouldn't it reduce the weight since the corner sits higher?
time table :
@2:10 load vs grip
@4:23 spring rate
@6:10 important note about cornering
@9:39 anti roll bars
@10:58 anti-roll bars effects on over-steering and under-steering
@12:06 anti-roll bars and the overall balance of the car
@15:15 under-steer and over-steer cheat sheets
@16:30 over steer and under steer set up and how wide the wheels are
Thanks
This series is simply IN-FREAKING-CREDIBLE! Thank you so very much for putting such effort into it!
It would be great if you could continue into aero, shock absorbers wizardry, chassis rigidity and so on. 😇
One of the best suspension videos I've seen, congrats!
On this topic: Your videos are the best comprehensible for me - by far!
Clear definitions! Very good graphic models that show what you talk about.
No shitty music!
I love it
Though lots of message have been leaved, I have to say that again "One of the best suspension videos I've seen!"
Yes, it was good. I enjoyed it as well.
I'm studying automotive engineering, I've been passionate about this subject since my childhood. Cane here to clarify some of the basic concepts. This was extremely helpful. Kindly make such videos on as many topics as possible focusing on the performance side. Thanks a lot.
Anti-pitch bars are useful but difficult to engineer unlike anti-roll bars. The main reasons are the anti-pitch bar will need to be mounted under the car's chassis as it needs to long enough to reach between the front and rear suspension arms. A tube or bar of sufficient length would be much lower in rate so it needs to have short arms and be very thick. It would be a heavy addition to both right and left sides of the car. There are ways around this but too lengthy for this post.
The advantage of anti-pitch bars is you can soften your spring rates to increase grip while maintaining overall wheel rates of the entire sprung weight system. In an ideal situation, yes you would want to utilize both anti-roll bars and anti-pitch bars.
Active suspension can achive this at essentially zero wheel rate with perfect anti-roll and anti-pitch coupling.
I recently cancelled the purchase of sway bars because I learned that they actually decrease the traction on cars with independent suspensions. My question is, why wouldnt I remove the sway bar completely?
@@MW-qo8hw Anti-roll bars decrease maximum traction, yes, but that doesn't mean that they aren't useful. Maximum traction is only really the most important thing in steady state cornering (like long sweeping sections). But during transient motions, you want to prioritise keeping the car level, as this will allow you to begin rotating the car faster, even if the absolute peak grip will be reduced. Running no anti roll bars at all will make the car really sloppy on turn-in and fast directional changes if you springs are soft.
Car setup is all about compromise. Are you going to be driving on a really fast race track with lots of tight, technical sections that require you to be agile through the corners? If you are, go get some anti roll bars. Are you going to be just using it on the mountain roads or in the street where you're not driving too quickly and the cornering radii are generally going to be much higher? Stiff anti rollbars are gonna suck, not because of the changes in handling dynamics (you'll feel the difference but it's not going to be too significant) but because it's gonna be bumpy as hell.
Anti pitch is generally controlled.by rebound damion on the rear in inbound damping on the front. Keeping the weight balanced during weight transfer is key. Lateral (roll) grip must be weighed against braking/acceleration (pitch) which is why sway bar and damper settings must be changed together
@@Not_A_Cat Here is the easiest method to achieve a well balanced and consistent balanced car. General guidelines.
1. Never use higher-order forces to compensate for incorrect lower-order forces.
2. Never use lower-order forces to compensate for incorrect higher-order forces.
3. Less force is generally better than higher forces.
4. There are fewer and smaller trade-offs when dealing with smaller forces. A lighter, lower and wider car will have smaller forces to deal with using spring rates, anti-roll bars, shock rates, and aero.
1st order forces:
Static weight distribution and Center of gravity height.
2nd order forces:
Jacking forces, unsprung forces, and sprung forces as well as aero.
3rd order forces:
Shock dampening and gyroscopic forces.
4th order forces:
Generally only achievable with active suspension and active aero. Such as velocity dependant damping rates and g-force dependant aero.
@@WhitentonMike I don’t know at all but u sound like a freaking genius, I like learning about this type of stuff. Is there a place or school you would recommend going to around the Houston area
I love visualizing mechanical functions in my head, and this video allowed me to do that, so thank you very much.
Excellent video. Looked everywhere for a good tutorial on this subject. Found this and don’t have to look anymore.
This kind of content tickles my brain. Thanks for sharing
I've watched all of this series. They are so incredibly well made! Thanks so much for the help and the amount of time that was put into these! Your Mercedes LS to modern videos are what got me started with your channel
This deserves more views!
right??
Towards the end of the video, it shows how much your front spring bends, and doesn't just go up and down, just like your rear springs, Just goes to show how all the "Keyboard experts" were telling you that "you must use coilovers", I think that proves perfectly that your rear suspension may not be perfect, but obviously works really well. I for one have really enjoyed all your videos.
I really love these educational videos about automotive engineering. You should do more and title them as such, as a suggestion. That way, they'd get way more views and the RUclips search engine would categorize them that way. These are really great.
Keep up the good work! Look forward to more in your channel.
One of the best engineering videos. One thing I could not understand, hope you explain. This diagram: 13:35 . You basically said the front (with anti-roll bar) has more weight transfer than the rear (without anti-roll bar). Wouldn't it be the other way around as that is what anti-roll bars are for (to stop body roll and weight transfer)?
I'm a year late but.
Every action has an equal and opposite reaction yeah? ARBs resist lateral weight transfer, therefore the axle that resists the most also bears the most force, which reduces traction, hence why you can use them to tune over/understeer.
@@Taverius bro can you explain? I dont understand wtf is going on, the anti roll bar is to stop this weight imbalance right? then how is it adding onto it?????
Weight distribution is not affected by ARB. ARB only changes body roll, remember force is energy that cannot be destroyed.
I wonder what happens if wheels are set to positive camber and body roll cancels inside tire camber, does it increase or decrease axle lateral force. I need a tire coefficient of grip versus positive camber chart.
Explains clearly and simply really advanced suspension behavior...
Thanks for this video! It helped clear up some questions I've had for a while about sway bars & spring preload. The way you presented this information was really clear, and the diagrams were simple, but very effective. Really great job on this video!
Thanks !
One of the best videos on brief explanation vehicle set up.👍👍
Great video. My previous car was a Citroen which had an hydraulic (edit: hydropneumatic) suspension. Now I drive a BMW and it is superior on every aspect, except for the suspension! It really was very good. Soft and no body roll. The Beemer also has hardly any body roll but it’s much stiffer.
Ah sure Hydraulic suspension. Another mystery to be discovered !
@@MrRobertFarr
Oh, ok Hydropneumatic. 😁
@@Conservator. my mum has a Citroen C1 . Hydro Pneumatic.
Hydro - of water (Latin).
Pneumatic means. Well, involving air, right ?
Sure, those mass produced suspension systems might be well researched.
I watched this series of videos.
He did not really mention, Stress transfer front to back, that much.
It's interesting to hear about.
The Torque Bars, he covered many of the concepts well.
Hopefully soon, I will break out my BMX.
He said, don't worry if you have, hydraulic suspension.
I used to work with hydraulic arms, actually.
@@MrRobertFarr The hydro-pneumatic suspension works with oil and air.
As far as I know, Citroen only fitted their hydro-pneumatic suspension (hps) on their larger cars (C5 and C6). The C1 has a conventional suspension and they’ve stopped using hps at all 5 or 10 years ago (unfortunately).
@@Conservator. Ah sure The Citroen Xantia maybe. My friend had a Citroen Xantia. Well, I read up about Citroen, I believe they were taken over by Peugeot. Did you ever see the French movie called : Taxi ?
This is the best informative tutorial, thank you. I have found answers to all my questions.
Awesome video !!!! You are helping me so much. I love racing sims and just started tracking my e46 m3 this year Your videos are really helping me out. Also I like learning new things at a fairly deep level and your videos are perfect for that. I"m really digging your channel. You are doing a great job on these videos. They're extremely well put together. Congrats on the quality content, and thanks. Give yourself a pat on the back :)
What a great video. This is still helping people out. Thanks for this year's later.
very easy for new guys, and very good for engineers! best videos i've seen.
At 6:00 he says that if you have half as much ground clearance, you will have to double the spring rate. That's true if you only use springs to resolve the settings. You could dial in anti-dive and anti-squat, and keep the spring rates lower.
this is so informative. 🥰 better than most of the videos presenting this topic
I only watched this video to tune my car in Need For Speed, but it was really helpful! xD You explain it really well!
Need for speed, which one?
let me guess, NFS Underground 2...
Wow this is the best explainer ever starting with the car models 👌
Mate… Legend, you are. I learnt soooo much. Thank you!!!
Very informative video, I already had a strong understanding of suspension systems, but this video has added to my knowledge. Thumbs up!
The reason I'm going for stiffer springs over thicker bar is because of one wheel bump situations (country road scenerio) sometimes in these cases it's better to look at Springs to maintain the indepent operation where it's needed
This is the best explanation I've found online.
It says sway bars are to prevent roll, but doesn't say why roll is bad or how much is okay. Loads are more balanced without a bar, so adding a bar makes that end unbalanced and reduces grip at that end. So while adding a bar to front or back can reduce grip at that end and change oversteer/understeer, it doesn't improve cornering g load.
I'm guessing the bar is needed to prevent the outside suspension from bottoming.
Also, the camber change reduces grip, so beyond a certain roll angle, total grip will start to reduce. So there is some roll stiffness that gives optimum cornering g for that end of the car.
Does this make sense?
14:40: This is a brilliant explanation
Yes, it was helpful in that, I am lying here exhausted and need something to keep me sane, without too much effort for my body.
It will help me explain what, I instinctively know is wrong with a motorcycle suspension with four springs.
The issue of front suspension on a bicycle and the absence of anti roll bars there and on a motorcycle.
I wonder what the horizontal suspension or springs were, under the car is, is that a form of anti roll bar ?
Thank you! I think I understand what's going on with my Challenger suspension now.
On 12:50 we are adding another sway bar on the front axle which means we are increasing stiffness in the front so the roll will be less with the load difference between outside and inside wheel on the front. But in the video the whole explanation was reverse between front and rear axle. Can anyone tell me if I'm wrong and where or there is a little mistake on the video. Thanks in advance!
Great great great video!! Clear up all my questions about anti-roll bars with nice graphs!!! Thank you SK8215!!
Forza taught me well enough to understand as a review
Genius and enjoy watching your channel keep up the good work .
Cheers
Very informative for both newbies like me and amateurs! Thank you so much!
8:40 every suspension kit I've seen that has separate spring perch collars and lower collar says that you should NOT be adjusting ride height with the spring preload perches. The shock AND spring assembly should be spun up or down into the lower mount brackets for height adjustment.
You are correct, when you have “divorced” dampers. Some dampers only have the upper spring perch for adjustment, but the manufacturer has already built in the amount of ride height adjustment for you, based on the spring length and damper travel characteristics.
Amazing series!! Would love to see the one on dampers one day please.
I just finishing refreshing suspension
Sway links, bushings, upper control arms, lower control arms, and outer ties rod
Did it all myself, I have b8 and lowering springs cmg
B8. Hmmm sounds like you got bilstein shocks correct?? :)
Blanco Escondido yes b8 shocks and eibach lowering springs
Really nice videos! I'm recommending these to my BAJA team: 'Team Piranha Racing'.
Thanks for sharing the knowledge. Great video bud !!
It also depends on the tire compound and width. Caster and camber are other factors which greatly effect ride and grip. Polyurethane bushings on sway bars are a must for track use. Dont cut your springs to achieve a lowered look. When a car doesn't turn it's called pushing and when it's oversteering it's called loose front wheel drive cars are prone to understeer and push rear wheel drive cars are prone to loose and the back end stepping out that can be remedied with simple tire pressure adjustments. Bottom line is if you don't have the money to do it right don't waste your time or your cash on some cheap half ass suspension because you're just going to end up stuffin your car and your insurance isnt going to cover it at the track. it costs money to go racing!
Your formula for Wheel Rate and Spring Rate is incorrect. It is Wheel Rate = Sprint Rate x (D1/D2)^2
The reason is you are not only changing the force but the distances traveled. Remember that a Rate is both Force and Distance so you need to multiply the lever arm ratio twice. So a lever arm ration of 0.5 would result in the force difference of 50% and the distance traveled of 50% or a rate ratio of 25%.
Also take in to account your sprung vs unsprung weight. Damping is more important than overall spring rates, and geometry can be altered to maximize the characteristics of any given dampin/spring combination. The whole science is relativity, one change requires 4 more changes to make the geometry work on a given road surface.
Really a helpful video to understand the suspension
Thanks for posting this. Very clear and makes perfect sense!
Any videos on dampers? Couldnt' seem to find them. Awesome videos by the way!
[thank, you for walking and explaning us all threw you're helpful video]👍
Have you already done a video on dampers as mention in this vid? Couldn’t find anything… aside: superb video on springs and ARBs, excellent explanation! 👍🏼
Awesome videos bro really am learning a lot and also seeing the gaps in my knowledge, can you do a video about frame design and tube chassis
Excellent vids. Learning a lot, thanks.
Excellent video. Thanks for the explanation.
Thank you so such this video is very educating on suspension system
From my understanding (don't know if it's correct or not) , by having an anti-roll of whatever stiffness, it's limit the overall body roll so you can keep the overall car CoG close to it's ideal spot in expense of taking out the grip of the tyre (either front or rear) as the anti-roll bar always unload the inside tyre more than the car should and load the outside tyre more than it should under weight transfer.
(Edit) I also think anti-roll bar does help with the car than run an underbody aerodynamic downforce where the ride height are crucial to keep the ground effect work efficiently.
If you add stiffer anti roll bars at both the front and rear then yes, they should only reduce body roll and have no effect on the balance of the car. If you reduce body roll you do reduce weight transfer by a bit but the bigger benefit of less body roll is you can run your car lower which reduces weight transfer further. So yeh anti-roll bars have both uses, reducing body roll and fine tuning the cars balance.
@@xfmotorsports sorry one more thing- I think saying that ARB is a device to get a certain balance off the car ( that is actually what gives that extra drivers confidence and ultimately speed ) and the less off ARB you can get away with- the better , is important so people would lose this misconception about them as one off the most important "speed" mods.
Boy, so much info!
You had said to adj. the the "top" of the Coilover @ the spanner nut/s and not the bottom where the male female threads @ the shock tube is, as far as ride height goes, I thought it was the other way around ? Plz clarify this... BTW the Video is awesome. Ps. I would want to go with front soft and rear stiff w/ a front wheel Dr car?
Okay so the basics are explained pretty well **BUT**,
I don't know if you are a race engineer or a hobbyist, but you're not right about the application of the anti-roll bar. If you move the antiroll bar from rear to front it will increase the roll at the back and decrease the roll at the front. And when you have an antiroll bar it means that it will reduce weight transfer, in your situation is increases the weight transfer, so you have an anti anti-roll bar? Then the understeer oversteer part... There is just 1 place where you will have understeer or oversteer that you can improve with the anti-roll bar, at the apex (initiation is more dampers). When you have understeer you want to decrease front weight transfer, so you stiffer the front antiroll bar or increase rear weighttransfer by softer the rear. When you have oversteer it is the exact opposite way. The springs are correct but it is more about the braking area. I hoped I helped you out and hope you understand I had to make this clear as I'm a race engineer in the European GT4 .
Not true
Stiffer front roll bar gives you understeer. Its commonly known if you ask any time attack competitor or even search it online. I've played around with roll bar settings on quiet a few cars and they make a pretty significant difference. You can try it yourself, just remove the sway bar end link on your front suspension. It will start to oversteer more.
I agree with only "And when you have an antiroll bar it means that it will reduce weight transfer, in your situation is increases the weight transfer, so you have an anti anti-roll bar?"
yeah u r right it makes sense
I agree with MTYD23 that if you have stronger roll bar at the front car will be more understeer. Same in opposite way. You can find more in channel Engineering Explained. You can find in racing set up videos like How to set-up a racecar? By Tom Coronel, Suzuka Japan WTCC 2013
This is also tested on the track. So please do not share this incorrect information.
1. 'If you move the antiroll bar from rear to front it will increase the roll at the back and decrease the roll at the front.' I mostly agree with the statement above. However, assuming the chassis of the car is reasonably stiff, this effect is relatively minimal.
2. I am pretty sure that SK8215 is right. If you increase the stiffness of front anti-roll bars (or front suspension), the car tends to understeer. Please refer to the explanation below.
3. 'When you have an antiroll bar it means that it will reduce weight transfer.' This is also correct **BUT** it applies to the opposite end only. NOT the same end!
For example, a front anti-roll bar reduces OVERALL weight transfer at the expense of increase front weight transfer. Thus, rear weight transfer is reduced.
Please correct me if I am wrong.
excellent video thank u very much,the animation is perfect,just a quastion, in case u would only put stiffer springs at the front(and leave the antiroll bars front and rear as it was on the initial set up)how would the weight distributed in that scenario?
spring stiffness does not affect static weight distribution. only dynamic.
Best Suspension class!
Thanks
You never made a video on multi link rear suspension!...? I'm building one and need a great lecture before I jump in. Thanks
Was playing Forza and wanted to tune little bit even though its a video game,
it has somewhat accurate simulation of physics that i can take from real life and apply them to the cars in the game and get the desired outcome.
(Forza Horizon 5 is Simulation/Arcade Racer not that extremally accurate compare to other even more in-depth hardcore sim racers out there with pages of adjustments you can tweak)
Feels odd sometimes looking up irl tuning guides and applying them to car`s in the game, but it gives me more incentive to learn about cars and how they work on a fundamentally level.
Great job making that understandable 👍
Great informative video.
Very helpfully. Thoughtfully explained👍
Ill try Your Tipps on my Rally Car in dirt Rally. I think this will solve alot. Everything Make sense.
Good video
How do you solve a cars front end swaying back n forth from left to right in a turn at high speeds?
Clarification ARB very detailed thanks!
Very helpful; infact the most helpful.
The Best Video Ever I Watched In My Whole Life I Understood Everything In By Watching Only Once The Video
Wow Love This Video
hi there, really appreciate your video, I love it! So if I lower my suspension by using after market ones, how should I change my alignment? Is the OEM alignment still valid? And if I want to make the steering sharper with quicker responsiveness, should I decrease the toe or chamber?
i cant understand that at15:46 , why do we soften the front springs to fix understeer, i thought it will further uneven the load between two front wheel, which will reduce the total front grip
Brilliant explanation, thank you.
Great video! one of the best I've ever seen about the matter, But I didn't understand the anti-roll bar exemple. I always thought that the ARB worked transfering part of the forces applied on the outside wheel to inside wheel, thus reducing the roll effect. What I get from your example it works on the opposite way, increasing the forces on the outside wheel. Is this so?
+1 on this, that confused me. I thought by adding the rollbar, the RHS would get -150kg rather than +150kg, since the torque on the roll-bar would counteract the weight shift on the RHS of the car.
Liked and subscribed, can you make a video with dampers , a fast bump, a slow bump, and rebounds 😊
Very Educational on BALANCE . ATI ROLL BARS . B ASICS . . . LOVE IT . THANKS
Can i suggest doing a feat with Speedacademy , this video series are really interesting
thanks alot SK8215 , really appreciate it.
Yep dude. Great vid again. Not much more that I can say !
Thanks. If possible can you make video about wheelbase.
What is this software that you're using?? Is it open source??
Very interesting content! 😎
I always find it a bit odd that they use the unit of 'kg/mm' , kg is a unit of mass. It would make more sense to use a unit of force because that's really want they mean by 1kg, they mean 1kg under earth's gravity.
In any case, I LOVE your videos, keep it up !
It's easier to calculate since mass of your car is in kg and material density of the spring you're using is in kg/m3. Why transfer it to newtons and back when you can make your life simpler, just make sure that you put diferent suspension if you're planning to go on the moon
Great video! Can you please share the name of the software you have used to create the animations?
That's what's i want to know. Come on tell us my guy
Very informative! There's one thing I don't understand when you put the rear seat bar to the front wouldn't the car roll more in the rear and less in the front?
The front and rear cant roll independently of each other unless the cars chassis is really wobbly. Usually chassis only flexes less than a degree so the front and rear body roll is more or less the same.
This can't be correct.
You even say in the video that you don't want your sway bars to be too different front and rear... Now you're saying it doesn't matter because of chassis stiffness? In a dynamic situation, like acelleration, weight shifts reaward and I'm 100% positive the rear can roll more than the front in this situation. I've seen the pics to prove it (rwd with no rear sways).
The reason you don't want extremely different sway bars front and rear is to keep load even otherwise you can end up in a situation with one wheel lifting off the ground (inside tire reaching 0 load).
The situation your talking about is pitching and rolling at the same time like under acceleration out of a corner. That still does not make the front and rear roll differently. The roll centers can be different front and rear in which case the car rolls around an inclined or declined axis but the roll is still the same front and rear
SK8215 I disagree with that and you even contradict yourself in your own rebuttal by saying the car can roll at different rates but roll will be the same f:r on the outside tires. That's just not true if more weight is shifting rearward due to acceleration and the outside front tire is unloading... the inside rear tire will squat and roll more than the inside front tire when accelerating out of a turn.
That's not what I said at all. Read the comment again. Roll is measured by the amount your cars body leans towards one side from horizontal. If your accelerating the car pitches back at the same time as well. That does not make the rear roll more than the front. Its just pitching and rolling at the same time.
Could u explaine the rebound and bump can u change over and understeer with the rebound and bump and is there a formula like having a 50 50 weight distribution the car weight 2000 devide 2000by 4 is 500 each wheel so i put my springs at 500 but how could u calculate the rebound and bump vs the springs its for a race game simulation great vid btw
What is the role of anti-roll bar bushings? What happen when they are worn? Everywhere I still read only squeak as related problem but nothing about drive sensations.
My car start with some squeaks in wet days and now, after some years, is a little unstable. I've new shocks and springs but the car have unpredictible body roll when I turn. I need to constantly adjust the trajectory because I feel all the car heaviness on turns like unflated tyres or bad shocks (but they are new now). The roll transfer when I turn the steering wheel is not progressive, it happen suddenly like heavy iron ball move on a side beyond a certain threshold
This problem could be related to worn stabilizer bar bushings?
Excellent explanation!
Does the added weight of suspension become prohibitive at some point . . .
Ergo . . . most go-carts and bicycles typify this response I do believe ! ! !
hi good morning, I have a question, I have a 2011 wrx sti sedan and I am running tein enduro pro plus macpherson style struts, paired with tein spec c lowering springs, my car handles like crap, very bouncy and wobbly, i have whiteline endlinks to install, can you advice me what might be going wrong?
So nicely explained
Did you do a damper video? I don't see it in the suspension playlist
so whats the best bang for the buck suspension upgrades for a 2011 2 door civic? i live in a very hilly area and lotsa curves so i want better handling but cant push it to limits to see if my car understeers or oversteers cuz i will end up crashing in the side of the hill or over the cliff?
does a stock civic under or oversteer typically?
bigger stiffer rear swaybar combined with fatter front tires would be one possible setup , right?
Wait... Using preload to do ride height? You use that for corner balance. If you use it for height, you'll end up bottoming out.
You stated that adjusting the top lock washers on the coil overs is where you adjust preload and ride height.. Can you explain yo me how this adjusts ride height over the bottom coil over body adjustment? It was always under my understanding that the top was only for preload and never for ride height... Very good video by the way
The cars weight can only compresses the spring by a certain amount so adding preload wouldn't compress the spring further, it just lifts the car higher. The only time it actually compresses the spring is when the suspension is at full extension.
The lower setting will also change ride height but your changing the point at which your suspension bottoms out every time you change that. Without proper bottom out settings the suspension could go past its normal travel range, so the tires could be hitting the top of the fender or the cars bodywork scraping the floor everytime it hits a bump too hard.
Ideally the bump rubber over the damper is supposed to stop that from happening if the length of the coilover is set properly.
@@xfmotorsports good job on those videos, just would like to point out about corner balancing, what you said in the video end comment here- when you do it with spring preload that's when you are changing the travel ( more preload will result in cars weight compressing the spring less , shorter distance) , and will have less effect on transferring weight between corners , plus it will vary a lot depending on your springrates. That's why me and people I've worked in the field with usually use mostly the hight adjustment perch for corner balancing and preload for damper travel ( or otherwise - a combination of both).
Good job again. And impressive self control on some off the comments obove .
It would depend on the design of the coil-over. In most common designs i.e "BC suspension" (with separate ride height and preload) range lowering or raising from the bottom will not change the damper piston stroke position. The whole suspension unit would be static in its own right and only be lowered or raised via the bottom cup.
If it only had a single adjustment point "spring perch". It would do both simultaneously. If lowering excessively it would reduce compression damper stroke plus on full droop ( when the car is jacked up ) your spring would be unsupported and rattle so they introduce helper springs.
I am not familiar with what's fitted in the car but the above rings true for most suspensions kits on the market. This kit may well act as stated.
just a question: @13:34 shouldn't it be +150kg on both the front tires? Or even +300kg on both, because you've got 2 sway bars instead of one, but that is less important than the first question. I mean, as you said, the sway bar will try to counter balance the forces from the roll movement of the vehicle, so it should add an equal amount of force on both tires, not adding to one and subtracting to the other, right? And i think it's also because if the total weight of the car is 2000kg, it means that in a static situation, the sum of the normal force on all 4 tires should be 2000kg, but under roll you should consider the force given by the sway bar(s), so the sum of the normal force on all 4 tires should be ABOVE 2000kg. It's kinda confusing me, i don't know if i'm correct or not, so please read this. Also, i must confess it's the 6th or 7th time i've watched this particular video, and i even watched more than twice all the other vids on your channel, you're one of my favorite channels, so thank you for all your work!
Hey, load can't be added on both front tires using an anti roll bar. Also, the example is assuming a car is going through a corner and the forces on the chassis are only lateral (no longitude forces), so it will transfer weight side to side but there's no weight transfer rear to front. If you add up the values from both front tires they are 1000kg before and after. They only time that will change is under braking or acceleration (when weight transfers longitudinally). Anti roll bars and spring rates will only transfer loads corner to corner but they can't change the weight distribution entirely. The only time you will get anything above 2000kg or additional added load over one axle is if there is downforce or some external force on the car. Hope it makes sense
Someone please explain to me. I feel like the section about adjusting the coilovers at the preload is wrong. Wouldn't you loose suspension travel? Also if you run helper springs or progressive springs it would affect the spring rates. (Heck even linear springs probably aren't completely linear). Adjusting the height should still allow you to adjust the weights and would effectively compress the springs more where weight was moved to, but without sacrifing travel/droop. Please help me understand.
Can you explain the castor vs KPI (king pin inclination) and how the geometry changes the way the vehicle responds
A question about corner balance. if I change the spring rate of the car but maintaned stock ride height, is my car balanced the same as before? I dont understand why increasing the preload would put more weight to the car, shouldn't it reduce the weight since the corner sits higher?
Goat no cap 🚫🚫🧢🧢🧢