How Does Torsion/Twist-Beam Suspension Work? Why do Manufacturers use it?
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- เผยแพร่เมื่อ 18 ต.ค. 2024
- Today we look at a type of suspension commonly used on front wheel drive cars known as twist beam or torsion beam suspension. This suspension is largely used by manufacturers as it is very cost effective, however it has a number of interesting characteristics.
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I've been struggling to find information on TH-cam about roll stiffness and torsion bar suspensions and this video has very clearly told me as much as i would like to know about the characteristics and tuning techniques applicable to rear torsion bars so for that - thankyou very much sir ^^
Just realised after seeing the comments that I didn't talk about the unsprung mass at all! To answer everyone's questions, yes, this sort of setup does have higher unsprung mass than IRS, and this will adversely affect the handling unless your track is dead smooth. And regarding the roll damping, it is true that the dampers at the back of the beam will provide damping in roll, however as they have to provide bump damping against the springs you can basically tune them to either damp bump or roll best, or a compromise somewhere in-between. The damping will always be wrong in a specific mode, but close enough for most purposes. This isn't just a problem for a twist beam setup, but is true for any setup with an undamped anti roll bar, as changing the bump damping changes the roll damping.
KYLE.ENGINEERS my 007 Toyota Sienna awd has this.
Thanks
Thank you very much. I've been searching forever for the reason of toe change in Torsion Beam but can't find any that can be used, as the explaination is very vague and sometimes doesn't even get to the point. Your explaination is simple and sufficient, focus directly on the problem.
Thank you! It makes sense why this suspension setup sometimes feels like the rear is upset over bumps. Keep up the good work.
No problem Devin, thanks for your video request and Patreon Support!
Men I'm 17 years old but I really learn a lot in this vids pls keep it coming!
Nice video. What I've seen some manufacturers do to add more roll stability and a degree of adjustability to these kind of rear suspensions is add an adjustable torsion bar inside the twist beam so that you can adjust how rigid that twist beam is. I had one like that on my 1988 Mitsubishi Colt, though on my current 2007 Colt Mitsubishi kinda cheaped out on it and simply used a beefier twist beam and completely done away with the extra torison bar.
That seems like the best approach, since the base versions of the car are usually both the softest and the cheapest, making them the logical use for the twist axle alone. Then, for each performance upgrade, a stiffer supplemental bar could be offered.
You have explained the basic phenomena very simply. Thumbs up, Five Start. Keep it up !
Good stuff. A multi-link video would be great.
I know this is three years old, but I immediately recognized the underside of the car at 5:32 as a 2012+ Mitsubishi Mirage/Space Star. I happen to own a 2014, and ran into issues with this particular torsion beam suspension. The axle stubs are welded to the assembly, so there is no alignment adjustment using shim plates. They have around -1.5* camber and about 0.3* toe in per side from the factory. Mine is lowered an inch on H&R springs, which nearly doubled the amount of toe in. Taking inspiration from another member of MirageForum.com, I had to attach a chain to the spring perches and use a turnbuckle to adjust the toe out towards zero. It actually worked surprisingly well!
Since I can't post pictures on TH-cam, here's a link to the forum thread with my setup: mirageforum.com/forum/showthread.php/2563-Rear-Wheel-Misaligned-(UPDATE-some-rear-axles-out-of-spec-warranty-replacement)/page40
This was great. I think it would be great if you did a video like this on the McStrut system that seemingly every contemporary vehicle is produced with. Why on earth is it so popular? It seems to me that it is horribly compromised in every way besides packaging. Is there really such a lack of space up front that dual A-arm suspension is impossible, or is it just a matter of saving dollars?
wtf is the McStrut? Is that a new McDonalds food item? If you meant the McPherson front strut design, the reason it appears in so many cars, is because so many cars are FWD, and cheap and the mounting of the engine affects how the suspension will be. So if you had a RWD car, which are now usually reserved for anything not strictly cheap or economically focused, they can have double A arm front or other types.
@@rmat9023 MacStrut obviously. You pedant. There are plenty of vehicles that use MACstrut up front that have no need for the extra space e.g. Nearly every BMW ever made or the 911 which doesn't even have an engine in the front.
@@bradcomis1066 The more you know! Thanks Brad!
Always thought my pulsar sss had a solid axle, this cleared up many things. Many thanks!!
you simply use shims between the wheel bearing and axle to change camber and toe
and also there is a benefit where you can achieve a rear ride height drop with brake torque, keeping the car more flat under braking
Great video, I have driven the FWD version of the Audi 100 Type44 (C3) with a Torsionskurbellenkerachse (torsion beam axle) and now I drive the quattro version with "Viergelenk-Trapezlenker-Hinterachse" (four-joint trapezoidal-style A-Arms, lower has a wide base and small top arm) and the ride quality and cornering is indeed much better, but the torsion beam is so simple, the parts (bushes and joints) I had to replace in the double-arm suspension after 25+ years of aging :-O It's interesting that Audi stayed with that design on the FWD C4 successor in 1991 in a car that was part of Audi's push towards a more premium brand. Of course the C5 abandoned the fully MacPherson front with torsion bar rear: Multi-bar everywhere and even more things that you can replace as your car gets old ;)
Might be worth mentioning that Audi (and others) use a Panhard bar (the simpler version of the Watt's Linkage you show) to locate the torsion-beam rear axle.
To be honest, even though Audi is marketed as a premium brand it never shows in their suspension setup. I mean their engine is fully in front of the front axle, not an ideal location.
Didn't stop them from dominating just about any racing series the quattro was allowed in ;)
Also, I think you are a bit too negative, starting with the C5 and A4 the four link setups were state of the art. 5-bar suspensions took a while and Mercedes did it a lot earlier, but they didn't have to feed the drive shafts through their Raumlenkerachse. Their W211 4matic uses a simpler front geometry than Audi's quattros, as far as I can see.
Great job,ive put anti roll bar to my torsion beam before,but it makes it less predictable.. After took it out my car handles much better in corners..
I like the new style. Keep up with the good work.
Digging the non whiteboard
What is more fascinating is that one of the best handling car you can buy uses a twist beam(the megane rs). But as always the complete system optimization is way more important than the specific components.
'best handling car you can buy' sure m8
im liking this video style btw, seems more professional, engineering explained is a step behind now
What!?? "I think it's called a Watts Linkage" very amateur presentation compared with engineering explained. This comment is in response to antsolja and no way reflects on the effort Kyle Engineers applied to make and present this video.
Love the content, thank you. I'm certain you have a surplus of requests but I would enjoy your thoughts and insight on roll cage design and other safety systems within the car (seats, HANS, fuel cells...)
Your videos are very informative. Could you make a video about the long tail aerodynamic designs such as the McLaren F1 Longtail and other cars that use it? Is it good mainly for straight line speed and acceleration or can it be good for cornering as well if the wheelbase is shorter etc? I wonder why it's not used more often? Maybe it's useful for Le Mans cars and not for road cars? It would be great to have your insights about it.
Perfect analysis, thank you! Just a question: if you add spring spacers to this type of suspension (in order to raise the ride height at the back), then the springs of the torsion beam are preloaded?
Alignments on this setup are done with shims behind the axle stubs.
Ah yes, but only if the axle stubs are not welded to the beam. Hondas typically use a mounting plate which will allow some adjustment, most others are just welded. I shimmed my Honda Insight for Autocross/Track with a slight toe out to calm down the understeer a bit, it can be steered a bit with the throttle now, love it.
Im sorry off topic, but i have a question, sp ive heard formula 1 commentators mention red bull having some sort of "slippery" paint, do you know anything about that, and could paint type and or surfaces affect aero on a car?
as for someone who had this kind of axle as daily, few roll bars at rear really could compensate it twisty handling
Great video! Seams like unsprung weight could be another issue.
Just a suggestion off the top of my head: I was thinking that if you were going to build a racecar using this setup, perhaps you could split the beam in the center and add a short torsion bar between them to allow for some adjust-ability. You could build the rest of the set-up to be as light and stiff as possible while transferring the twisting action to a torsion bar, possibly mitigating some of the fatigue issues.
Will Hoon For Food+ A simpler method would be to have a very bendy beam and bolt an ARB onto it to add stiffness. There's already aftermarket bolt on ARBs for stiffening the twist beam on some cars.
you can add some extra stiffness to resist roll by adding gusset(?) plats between the centre of the H down the inside of the trailing leg and some FWD rally cars add adjustable rods from the inside centre of the H to the inside of the trailing leg to give toe adjustment and camber adjustment is done via either washers/shims or shim plates mounted between the torsion beam leg and the tub axle
Every car that I drove which used the rear twist-beam suspension understeered a lot and the rear felt really soft (low rosistance to body roll). From what I have researched, twist beams really like to lift off oversteer because the outter wheel toes out under load and then, when you lift off and unload the wheel, it toes back in mid corner, which makes it oversteer. Now, I guess that manufacturers, in order to make their cars not famous as oversteery death traps (Chevy Corvair), just make them super soft with very little roll resistance so they can "never" oversteer which kinda ruins them imho.
I like the new style of video!
Love the videos! I've been following you're channel for a while now and have a request if you could explain "draw stiffeners" such as the ones on the new BRZ tS? Thanks for your time!
Is it a good idea to weld a strengthening bar to axel beam?
Nice video. I have automobile exam next week. thnx
Independent suspension it's the first thing that I want from a car even if I'm driving a fwd with beam suspension . Looking at the comments looks like I'm the only "multi-link" and "double wishbones" dreamer . Please tell me , talking about agressive driving (FWD too) high speed driving and cornering ( 100- 150 kmh) , why it's better an independent suspension?
This video was great do a video on multilink independent suspension
Nice. Not a lot of videos like this, but I suppose with the type of cars they're put on (lowcost consumer cars), there probably isn't much demand for it (it was good to find this one though).
Video approach is appreciated. Thank you.
I just stumbled across this video. I’m curious as to how this compares to Honda’s similar but different rear suspension on the first-generation CRX (and Civic and Integra). In that case, the beam is free to rotate in relation to the wheel on the right side, so a separate sway bar is used in lieu of the tube itself. Are you familiar with this set-up?
this channel is underrated
I don't really understand why more manufacturers don't use split torsion bars for rear suspension like Renault did in the 9 and 11 - it probably takes up about as much space as a torsion beam axle. Am I missing something why torsion bars really haven't been popular as a rear suspension type for front-wheel drive cars? Is there increased maintenance?
thank you for this great vid
And for some reason this is favourable to a solid axle?
That seems even simpler and cheaper to me, without seeing a big disatvantage to this setup.
When driving my torsion beam car, I can feel the rear oversteering noticably when accelerating out of turns.
Sir very good content & given insight about rear twist beam .It would be better if you can show some list of advantages & disadvantages between rear axle suspension & twist beam suspension comparison .Means from design ,ride & comfort ,also from structural life .Other question inside beam there is torsion bar is used but is function of that .Other question is coming to if we are having torsion bar inside the center beam still we need anti roll bar to add extra .
good information. thanks a lot. I have one question. what parameters will get affected if I move the center beam away from pivot towards the wheel center.
How about mass of the system. Does is have an effect on suspension behavior? Mainly on track use.
Dear Kyle Engineers, yesterday I accidentally jack up my car at the rear torsion beam to exchange my rear tire. It took about 20 minutes and today I read my car manual, it says don't jack up at the rear suspension. Is there any harm to my rear torsion beam suspension if I jack up at it? Thank you.
Very interesting. Thanks
Might want to also mention the De Dion Tube..en.wikipedia.org/wiki/De_Dion_tube
at 8:00 Mac strut is an example
There is definitely damping in roll. The shock in my ABARTH is mounted to the rear of the beam.
Hi, very cool. Thanks.
What is the correct way of finding the roll center/instant centers of a twist-beam type rear suspension? This is something I've had a hard time finding information on. I've found people procraiming it's anything from "ground level" (at all times) to being dependent upon the beam angle(as seen from the side).
What's the difference between multilink and double-wishbone/double A-arm suspension?
multilink has 4 or even 5 individual arms. An A-arm has two rods basically welded together to from an A.
Multilinks is top of the notch in ride quality, perfect for optimizing toe and camber curves.
But high R&D costs. I think for racing it may not be as strong as A arms.
the point of multilink is to control the wheel deflections better and not modify the suspension geometry
aero for cars with torsion beam suspension video needed plzzzzzz
The new format is better. Next step - drawing screen :) but do always have a camera - it's important to see the talking person. Thank you for interesting videos!
Can you talk about semi independent suspension? It might be the same thing as this, I'm not sure, but I seem to remember my car had a Y shaped rear suspension with just one pivot in front?
What does you mean with "roll dampening" ? Whats part of rear independent suspension gives that behaviour? Why the ride quality Is much better, of al least thats the common beleaf, in a irs than a torsión beam? Sorry for my english
You really need to do a analysis of the Mclaren Senna!!
Hy.
I have 2 Ford's with helical spring and a Mitsubishi with torsion spring.
Which spring is better?
Would be cool to explain the peugeot 306/citroen xsara trailing arm with torsion bars and 3 degrees of passive wheel steering!
Hey, Can you do an aero analysis video on the new McLaren Senna? It looks really interesting.
i have a question you could do a video on: why do car manufacturers angle shocks and springs? wouldnt angling them make them less effective? its somthing i see ever car do but i cant figure out why
antsolja Top is angled in because the tire is in the way. Bottom is angled out to have more effective leverage on the arm. Not all are angled though, my E46 rear Spring and damper are almost vertical.
Thanks a lot sir.....
Any chance of an aerodynamic analysis of the McLaren Senna, looks pretty interesting especially below the rear window.
If both wheels are connected means wheels can't rotate independently? How this effect vehicles ability to turn?
11:20 - You've revealed too many automotive secrets, Kyle. The police is onto you.
Is this different from a sway bar?
I know a rear beam axle is laterally located either by a panhard bar, watt's link, or scott-russel link.
How is the twist beam sispension laterrally located?
Can we put a panhard bar on a rear twistbeam suspension?
jpogi gtxcr1 Opel/Vauxhall uses a watt-link on the Astra, which has a twist-beam rear axle
Maybe instead of drawing as you talk... have the pics pre drawn for the presentation 👍🏻
Sir can you talk about the aerodynamic of alpine a110 with its diffuser
Hi Kyle, could you please make a video of the Mclaren Senna's aerodynamic package please?
I think it might be better to have a couple good pitctures of the suspension and mark up over top of them and you aren't the best drawer. Thanks though, your suspension explanations are sweet.
God your channel is great. Thank you for doing this
Why are the bushes not in the same axis, unlike door hinges?
is this the same as a motion control beam?
nice chazzi!
my autocross car has this rear suspension setup but it also has a panhard bar how does that effect the system?
This would rather be done like in the Peugeot 205 GTI where the wheels can move individually thanks to separate torsion rods.
😢 I have used rope in the tortion beam, to pull out my car in mud....Did this hamper my car alignment??????
Importante la ventaja aerodinámica‼️
Understood the purpose of beam setup, but why is it called twist-beam?
this system almost killed me on my volkswagen, there was little rain and in the turn, the car suddenly went oversteer ditching me almost , left the pedal on the gas , prayed ... Many died with this system on a volkswagen, the dutch even call the golf " boomplakgolf " in other words treehugger or treekisser. with my alfa romeo armed with multilink I feel way safer and not be betrayed by my car because the car is more forgiving and hasn't got that skizzoidity of a torsion beam
ah yes the torsion beam is a bitch, it's harsh on your sciatica nerve while handling sucks
whats the motion ratio for twist beam
Could you have active under body features and a long rear spoiler for both streamlining and downforce at low to medium speed? A tarmac rally car under your car. 😂😂🇦🇺🤩
So why this over a leaf spring solid rear axle?
Edit: liked the video style!
A leaf spring setup is actually quite big, which compromises packaging. Here you can get the wheels right at the end of the car meaning loads of interior space
Leaf springs are heavy, and behave weird as the axle shifts forward and rearwards while in a bump.
A better comparison is just a rigid rear axle combined with Panhard and/or Watt linkage.
Without these linkages any solid rear axle or a leaf spring setup will have the roll center at the road level, this torsion beam style raises the roll center to a bit beneath the spindles. Leaf springs and solid rear axles will have to be used with RWD as the torsion beam will not be easy to get it done. Or otherwise more expensive Individual arms.
I came back to this video because I was thinking about applications for torsion beam suspension. What are your thoughts on using this style for front suspension? Does that change the advantages and disadvantages?
It's.. that's straight up a bad move.
Torsion beam on front wheels wouldn't work well, mainly because there's no space since the engine takes up the majority of the front space. There's no free room for the beam to twist during cornering or hitting bumps, that would just put additional stress on the frame and it WILL damage the oil sump.
Having a semi-independent suspension for the front wheels would cause a lot of problems, including front wheels losing traction at un-even surfaces, floaty steering response in particular. With torsion beam setups, camber is really limited which also can affect the handling in many different ways.
MacPherson and Wishbone, or any independent suspension in particular is always the best way to go for the front wheels.
@@OzoneRRCan torsion beam at rear cause dizziness to rear passengers? Puking at winding roads?
@@wolger Any type of suspension can cause dizziness to passengers, especially in the rear and at high speed.
Torsion beam is just a cheap and practical solution meant for daily use. For sport driving independent suspension is far better.
He did not talk about the car sagging in the back
The Harry Potter of engineers
is there any rwd cars with torsionbeam
Kian Hazrati old muscle cars, 04 mustang, Drag cars.
suzuki sx4 is awd with torsion beam, has a differential mounted to the body and cv shafts to the hubs
could you put subtitles in Spanish please thank you
If that's as much effort you're going to dedicate to "computer graphics", I think the whiteboard is WAAAAY better.
Anybody else came here after looking at Ferdinand (Elefant)?
Pls do animation of this
i have a question. u know mercedes f1 windshield, is it actually for aerodynamic benefit
first thought: honda fit/jazz
And I hate this suspension, no feeling at all. Can't feel the grip on real wheel.
still huge in formula one
It doesnt much...and because it is CHEAP......a pathetic system compared to what is possible with todays technology or even tech from 1950's in some cases...
Probably bad off road?
Man, I don't think you are eating well.
Torsion Beam Suspension is probably the worst kind of suspension in terms of reliabilty.
Any Peugeot 206 owners here? 😂
Pug 206 / 306 didn't use torsion beam suspension. It uses a trailing-arm independent suspension using torsion BARS (a coil spring is a torsion bar which is simply coiled). Drove my old 306 for 250k miles and no suspension components (except dampers of course) were replaced. It's inherently VERY reliable and hard wearing.
@@khalidacosta7133 Thanks for clearing that up. Well, mine is completely gone, both wheels have a lot of negative camber, and one of the wheels is shaking over 35 mph. Right now I'm looking for a decent used unit, but it's hard to find one nearby that's in good shape. Might have to order a brand new.
@@astanisystems Considering the youngest 206's are now 15 years old, that's not bad going. There's a few companies which can service the entire axle for around £200, its usually the bearings inside which get worn. Should cost you £350 incl labour for a complete overhaul... That is reasonable... If only I could overhaul the suspension of my multi link rear for that cost (£750 last time I looked!!)
@@bigkification Problem is, the axle has been tampered with, weld spots all over the place and missing parts. I don't think it can be repaired, plus it's rusty. I may need a new axle after all.
Great video. My car have anti roll bar inside the middle part. I think like that they can fine tune the system for diferent version on the car. (mine its sport version so i guess on normal version this antiroll bar is smaller). To adjust geo I can use stuff like that : www.mikadoracing.com/annonces/images/01_2016/0_1776383_13747_CALES_JA.jpg that are inserted between the hub and the whole thing. To decrease the stiffness of the roll bar on race version of some car the Antiroll bar inside is disconectable or you can change it. On road version unfortenatly it's fix but if you upgrade with race part can be adjusted after. Here the race version of the clio : bruno.longepe.free.fr/photos/clioR3/2trains.jpg
How to calculate the torsion force acting on car during cornering .
Can you please tell me ??
You have to do some hard physics ^^
Honestly for a FWD car this is the best setup. Independent isnt as beneficial or as durable. AWD will work too just not RWD