"understeer works like this: you drive down the road, turn the wheels but the front keeps on going and you crash into a tree and you die. oversteer works like this: you drive down the same road, turn but the back keeps on going and you crash into a tree and you die, now oversteer is better because you don't see the tree that's going to kill you" -richard hammond
I think it's in the sense that a more experienced driver can easily negate oversteer without going too far out of lane, while understeer forces you to take a wider turn and therefore prolong the time where you're in danger of hitting other cars
Understeer is when your front end hits the wall, oversteer is when your rear end hits the wall, horsepower is how fast you are going when you hit the wall, torque is how far you move the wall when you hit it.
Im so sad i just found your channelt the other day and i saw you actually just stopped posting recently. Ive only been here but i absolutely love these videos and i feel will really help me prepare for automotive engineering school. All i wanna say is thank you
BmanUltima "If you go through the pearly gates backwards in a fireball, that's a cool way to die!" - Jeremy Clarkson. Also, "Oversteer scares the passengers, understeer scares the driver" - Someone else
phant0 That is only if the driver does not hit that tree =) I would want to be a passenger in an oversteer car with a good driver, and understeer with a bad one.
SUBSCRIBED! Glad i came across your page again! last time i saw your page you were only about 30k in on subscribers! Glad to see your growth and congrats on the award! And thank you for providing the community with your videos! I am sure i speak for all when i say you've taught each and everyone of us something new.
Hello there, Great videos !! guess there exists another way to reduce under and oversteer Modern cars brake the wheels individually and induce a yaw moment to correct the Under/Over steer.. Scenario > If you are taking a left turn 1. Understeer > Brake the left rear wheel so that a yaw gets generated to help the car get back on the intended path When you do this, the amount of utilizable lateral force on the front axle increases >>>> Helping you to get into the curve 2. Oversteer > Brake the front right wheel so that the front axle loses the amount of transferable lateral force >> Induces a understeer to compensate the oversteer and help the vehicle to get back on the intended path....!
Good explanation ! initially for awhile now i've heard some different explanations that actually cause you to get confused. I remember even reading an article where it was easy to misinterpret what they are trying to explain. Before i thought understeer was the opposite of what it actually was until i watched this. Good stuff.
Oversteer is generally unintended and results in a spin. Drifting and power slides (which are the same to my knowledge) happen because a car is prone to oversteer, and is able to be controlled by steering in the opposite direction to prevent spinning out. So yes it is.
Namaste. THANKS A LOT sir I'm doing automobile engginering and your videos are very very very useful to understand thing's better. If YOU ever come to India PLEASE let us know....my friend's and me are your big fans. THANK YOU.😇
Love your videos and would love to see a video on shock absorber setup in race car and the effects of different settings on adjustable shocks and springs
To get even more technical; maximizing tire load (per condition) can optimize g-force loading, thus helping to achieve the right condition in the right situation. Softer front end--giving some dive--in combination with mild anti-roll can achieve good cornering control while trail-braking, yet keep the car neutral mid corner (actual values dependent on tires).
As I was reading some of the comments...I thought the same thing...factoring in the type of tires in the vehicle have alot to do with the traction and reaction of the vehicle too...
Craig Cundiff Yes, unless the car performs fairly neutral on the limit, unless there is a drastic change in maximum cornering force. Generally, the higher the lateral g-force, the stiffer the spring rates and anti-roll need to be. And vice a versa.
When you say 'reduce understeer', I'm assuming that you are saying we want to reduce the front slip angle, therefore to reduce the front tire load....so you said 'to reduce understeer, you can increase the front downforce in order to increase front tire load'... i'm not sure you are right about that part. What do you think?
Can you do a vid to explain why that new Z06 crashed on acceleration, similar to how that M4 did gunning it out of cars and coffee? Was it driver error? Tire temperature? Characteristics of the car? Gear selection? Etc? Most people in the comments of those videos just seem to criticize the drivers but no one seems to actually explain what went wrong with much credibility. Your thoughts would be appreciated, and probably attract quite a few views if you can mention those crashes in the thumbnail/title since they have a lot of views too
SoSickWidit Well I haven't seen the videos you're talking about, but ultimately drivers are the ones in control. If they crash, it's a result of the actions they took (perhaps not understanding the limits of the vehicle). I would anticipate a little too much throttle. :)
Hey man, great channel you have here! I drive a 2015 Audi TT-S. Great car, great drivetrain, but it understeers a bit too much. Where do you think I should begin my quest to kill the excessive understeer? Front / rear ARB? Front tires? Thank you.
+Ricardo Lourizela I would start first by trying to increase front traction, rather than inducing oversteer. Maybe playing with the front tire pressure (slightly lower) and camber (slightly more negative) to see if it can drive a bit more neutrally. Then maybe move to the rear arb (or reduce front arb) if necessary.
It's a road car, it's legally required to understeer, and this has much to do with the fact of the weight distribution (CoM location), and cornering stiffness of the tires (matching cornering stiffness to the vertical load on the tire is the critical thing here). Ever notice that 'sport' sedans (M3, S4, etc) have larger, wider tires on the rear axle then on the front? This ensures that the rear axle has a higher cornering stiffness then the front, which is critical to stability, which is important to the legal department of the vehicle manufacturer. In order to reduce understeer in a production vehicle with a greater portion of it's mass resting on the front axle, the larger tire should be placed on the front axle. Changes in camber and tire pressure will have fairly minimal effects (provided the same tire is used on the front and rear axle....hint).
Why you always stop talking when it's make sense in to my head you have the information so do it wright keep talking give us videos when you explain things it make everything easier but you good and I like it even the car review its new revolution that you give us any tiny little things like the under the hood good channel and good information
Thanks Engineering Explained , great vid, now i'm gonna hop on need for speed shift 2 unleashed and tune my FWD cars for a little more oversteer now that I know how to do it lol
If I increase the front toe in would I not have a higher slip angle for the wheel with higher load when I turn and thus increase the lateral force created by the same steering angle?
So the old Preludes with 4 wheel steering, does the movement of the back wheels change the toe or slip angle? Or is not considered changing anything since it's "steering?" Does 4 wheel steering help neutralize things??
Under steer, when you feel like the front wheel is going to hit the barrier around the corner, over steer is when you feel like you are going to slap the rear tire into the barrier .
Hi, in your next video, can you go a little deeper into why adjusting the stiffness of the front/rear anti-roll bar will get you more oversteer/understeer? I recently installed a rear ARB on my subaru but can't figure out the physics here. Thank you so much!
Benny Tang My explanation would be that body roll allows more weight to transfer to the tires of the car on the outside of the turn, more force pushing down on those tires increases friction/grip, if you reduce body roll then a lot of the centripetal force on your car caused by making the turn will not be absorbed by body roll but will be put on your tires horizontally causing them to slip out more easily. You can use this to your advantage, after youve done some engine braking and trail braking to scrub off speed before a turn, try giving the brakes one last hard pump, this will transfer the weight of your car to the front tires allowing them to grip more strongly when you turn the wheel (but you may have to watch out for some oversteer coming out of the corner)
John Doe Force on the tire does not linearly give more grip. You get less increase in grip than the increase in weight due to the rubber giving up. He made a video on this earlier. Because of this, you will get and advantage of having a low centre of gravity and a stiff anti-roll bar.
Benny Tang The reason changing your arb stiffness effects the over/understeer has to do with the steer gradient. The steer gradient is a function of "tire cornering stiffness" so if you increase the stiffness of the front much more than the rear you add understeer. Doing the opposite by increasing the rear much more than the front adds oversteer. That's a short explanation, maybe Jason will expand on this more...???
jfurli what you just described there is exactly what need to know why. Generally an ARB adds more stability to the car, and adding a rear ARB intuitively adds more stability/traction to the rear, which, however, adds oversteer! I need a scientific explanation why a more stable rear end can cause more tail happy oversteer. Shouldn't it happen the other way around?
Benny Tang I am going to interpret your definition of "stability" to mean less load transfer to the rear of the vehicle but the front would be able to experience more load transfer. This increase in the weight on the front of the vehicle is what causes the oversteer just like Jason explained in his video.
What cause the slip angle difference between tires of front and rear axle. For example in understeer scenario the tires at rear axle experience less slip angle than front. Is it because the lateral force resistance is low at front axle tires due to less weight at front???
Understeer is when the front of your car hits the wall. Oversteer is when the back of your car hits the wall. Torque is how far you take the wall with you.
Gasinduced I wish people would stop saying this. The only thing that affects how far the wall travels (and let's be honsest, most of the time they're far more rigid than your car, and the wall will remain stationary while your car crumples) is the mass of your car and the speed at which you're traveling.
Engineering Explained Seriously!...however, in their defense, more torque = more horsepower = more speed which in turn does effect how far you are taking the wall with you. (it is just that the difference is probably much less for the wall and alot more for you and your car)
Am I right in thinking that softening the ARB on one end gives more grip on that particular end without taking away grip from the other end? If so, then surely it's preferable to soften the ARB where you lack grip rather than stiffen it on the opposite side thus giving you better balance and more grip overall?
I believe it's also solely on the application... for AWD (WRX 16) owner here... To reduce understeer we put a larger/stiffer ARB on the front to prevent less body roll on the front side giving more contact touch to both tires = more traction. At the same time, if we put an ARB too Stiff in the back it'll make it come out more... again for Subies but I would believe this would be similar to other applications.
I have some issues regarding the roll axis inclination... We are designing our atv for oversteer...I have gone through lots of articles and forums and have found that the rear roll centre should be below the front roll centre....but at the same time I've come across some articles which says that the rear roll centre should be above than front roll centre... please guide me
just a little point. Oversteer wont really get you to go around a corner more quickly like the green arrow implies. Oversteer is only really a benefit on something like a hairpin where you need to "flick" the car
brad ley Correct, perhaps I didn't make it abundantly clear but I was trying to imply the back would kick out and you would spin around (with significant oversteer).
Why does adding downforce decrease understeer? Isn't slip angle proportionate to the normal force/weight, and thus proportionate to downforce? (Same goes for oversteer btw)
wouldn't it be like when you increase the front downforce the split angle for front will increase causing an increased understeer? But you said it'll reduce the understeer. Will you explain me how would it will decrease understeer?
Than you for the great info as always :) I just have one question, my car is FWD and I am bit confused to set a staggered wheels (wider in rear, maybe 8 in front and 9 in rear), would that be OK??
Wouldn't an increase in the load on the front axle actually increase understeer? Since an increase of the load automatically increases the tyre's desire for more slip angle this would mean that as a result the slip angle of the front tyre will be greater than before and therefore it would be a step towards more understeer. Please someone correct me if the logic is wrong
question/new video idea: how does weight balance influence handing? why a lot of weight over the front axle makes the car understeer (let's say an audi) when even no weight over the same front axle makes the car understeer too (let's say an early 911)?
mrbigtian If your chassis isn't very rigid some of these can improve steering dynamics, but it won't be quite as significant as the other factors unless the chassis is super flexible (which it more than likely won't be).
Bugside almighty Unlucky! Similar thing happened to me as I was driving home months ago. Luckily I managed to correct it as much as I could and only clipped a fence at the side of the road.. few deep scrapes and small dents in the sideskirt! :(
I never understood this, if friction force is equal to the mu * the normal force, how can wider tires be more beneficial towards gripping and steering on the road? I was wonder why you see a lot of race cars and dragsters with massively wide tires and looked it up to find that its not the width that adds friction, its that the tires are stickier/softer, and the width compensates adding stability to the tire itself. So how can simply wider tires in the front/rear help reduce understeer/oversteer?
John Doe In a nutshell, understeer happen when your front tires have more than they can handle, and oversteer is the same thing but for rear... by giving wider tires (more surface area, more contact patch), it gives more juice to the tires to handle more. again, as the video explained towards the end, there are MANY things you can do to change the behavior. Personally, instead of just increase the tire width, I'd suggest you first go with strut bars, sway bars, or spring rate. Since in most cases (for DD), if you increase your tire width in the front, you would want to also increase it at the back too, and if you do that, your under/over steer characteristic remain would unchange. Unless you drive a race purposed car, in that case you could run different sizes tires between front and rear.
totszwai I see what youre getting at, but what I mean is that (bare with me im just a senior in AP physics, I know this stuff gets way more complicated) the force of friction stays the same no matter what the surface area is, so wider tires shouldnt really make a difference as long as the normal force and coefficient of friction stay the same
John Doe Wider tires allow the use of softer compounds which gives better traction/grip. Narrow tires need harder compounds to support the sidewalls. A fat tires has stiffer sidewalls and can use softer rubber.
Hey Love your videos but i have trouble understading toe in and toe out characteristics can you help me. That whoud be awesome. And Keep up the good work.
Engineering Explained I have all ready wacth it but here you say that reducing toe in on front tires help to reduce understeer for your other vid you say that front tire toe in helps car handling if the car is rwd if its fwd its toe out that benefits that confused me a litte bit what did i miss thanks for the help and what set up is used in awd cars ?
Engineering Explained I have all ready wacth it but here you say that reducing toe in on front tires help to reduce understeer in your other vid that is explaining toe in and toe out you say that front tire toe in helps car handling if the car is rwd if its fwd its toe out that benefits that confused me a litte bit what did i miss thanks for the help and what set up is used in awd cars ?
So, technically, Oversteer is the Understeer of the rear tires? They still want to go foward while the front tires want to turn, opposite of Understeer.
Understeer sucks mostly going downhill on winding mountain roads. RWD always does feel more natural to me though. I feel more safe and confident knowing the limits of tire slippage in RWD cars, while FWD just still feels weird to me.
Why do AWD cars generally understeer than RWD cars, which usually oversteer more. I know they are exceptions, but in general why do AWD cars understeer more than RWD cars, even though they should actually provide better traction?
+SIMcityplayer2002 Because it breaks the limit of traction for a tyre. A normal tyre has roughly a max grip of +/-1G and tyres use that force for a number of things. In an AWD vehicle, the rear tyres are using the grip (G's) to accelerate or decelerate, whereas the front have to share that grip of acceleration/deceleration WITH steering the vehicle. If power distribution is even in an AWD, you will always get understeer simply because the grip of the front tyres gets maxed out.
The speed of it depends on many different factors. The speed of the car, the traction, blah blah blah. If it's a sharper corner, then oversteer is faster because of less breaking needed, and under steer is probably as fast or faster in a shallow corner. But in real life you'd want neither, and would try to find the apex of a turn and keep as much traction as possible.
Alexand21 Though not that uncommon. Most cars will understeer at turn in, and depending on the set-up oversteer becomes more of a problem while exiting the corner.
DevasionX if you are driving at speed limit it will not oversteer. i had find out that it likes to understeer when it is in limist. cars are designed to understeer. put it overstrees at snow.
manager96ful I see E36s oversteering all the time on touristenfahrten crash videos. Older BMWs have very high rear spring rates compared to the front. For example my E30 has 4kg/mm rear springs from the factory, while the fronts are in the 2.5kg/mm range or so. The front anti-roll bar being larger helps to keep this somewhat balanced, but having the rear springs stiffer than the front creates oversteer balance.
Bruh in Forza Horizon 3,I put a Camaro or some kind of muscle car engine inside a 1940 Ford coupe,the thing can't even make it around corners without oversteering.Meanwhile,I have a 1949 Mercury Coupe,doesn't even do anything.
Don't agree with the actual path on the oversteer drawing. If you're going fast enough to make oversteer then you are going to run wide in oversteer as well as understeer. Oversteer does not make you turn a smaller radius than intended.
sky17 Actually great point haha, perhaps misleading for some cases. The goal wasn't to show that the car is capable of a sharper turn, but rather it would be much more prone to spin out. Without counter-steering, the car will not continue to face the intended path, but rather towards the inside of the corner. The actual path will be based on how the oversteer is initiated and at what speed it occurs, as well as how the driver reacts through steering input.
Just wondering. Wouldn't slowing down a little on public roads reduce both understeer and oversteer? Take the turns at a speed that the car can handle, and that the driver too can handle. And guess what, it doesn't cost any modifications to the car, plus you'll save gas.
Yes, staying within the limits of the car will result in neutral steering. This video is more emphasized towards track driving where ideally cornering occurs nearly at the limit of the vehicle's traction.
Moi MacArt Obviously cornering at slow speeds will reduce these effects on dry roads, but in adverse weather conditions being able to control the vehicle when either occurs is a matter of safety. Many drivers are unaware of these effects entirely, and as a result traction and stability control are a necessity. In areas with snow or ice, lack of lateral grip can only be counteracted by coming to a complete stop in certain situations.
TheZigZagg True. It is why we usually need to drive for the conditions. In adverse weather conditions there is only one secret, to slow down. That said. It is true that anything can happen even at low speeds. And it is a good thing to understand what is explained in this video.
CLV$$Y haha is this a joke? I only ask because I saw an aol headline that encouraged left foot braking and thought "how stupid is that"....but if youre serious elaborate please
John Doe is not a joke, it depends on your situation, but take FWD car for example, if you are understeering, the amount of weight bias is shifted to the front, causing your front tire to have more load than it can handle. By using left foot braking (while also keeping some throttle opened), you essentially applying your brakes WHILE trying to accelerate at the same time. This in turn makes your rear wheels brakes a bit more than your front wheels, which in turns making less weight transfer to the front, which in turn giving some breathing room for your front tires. In addition, using left foot braking, you can also keep your rev a bit higher to stay within your powerband, so when you exit the corner, you will be at the sweet spot where the engine makes the most power... With that said, left foot braking takes lots of practice and needs getting use to. For starter, because your left foot is not used to the pressure, you will normally end up applying too much pressure on the brake pedal, and could be quite dangerous. There are other use of left foot braking as well, you can Google them up or check them out here: en.wikipedia.org/wiki/Left-foot_braking Personally, I configured my FWD to be a tiny bit of understeer, and just throttle lift to make it neutral (would oversteer in the rain). Is more fun and easier to drive as DD.
And then there is AWD with random switches between understeer and oversteer, followed by violent death. Half a joke here. It takes much more time and distance to stabilise it though.
oversteer isnt always better, NOT EVERYONE WANTS TO DRIFT. There are people who doesnt like oversteering and you have people who THINK its fun and end up wrapping your car around a pole SIDEWAYS, with little to no crumple zone... So many bmw drivers in my country died in sideway crashes.... all morons who just got their licence and watched too much FF and played too much N4S
JimmyEG1 Ford Focus, is fwd not is locked on the road by its excelent suspension
4 роки тому
This is pretty much incoherent and useless. Oversteer is what my parents' brand new 1968 Buick did to me the first time I drove it. Went around a residential corner to the right, eased up on the steering wheel so it would slip through my fingers to let the car straighten out on the new street. Car just kept turning to the right, almost up on the neighbor's lawn. Had to steer it out of turns, unlike the old Buicks and Chevvies I always driven.
Nope....sorry; probably an excellent engineer, but this young fellow talks like 99.9% of engineers I've EVER encountered: way too technical. But, on the other hand, this is an "EE" episode.
"understeer works like this: you drive down the road, turn the wheels but the front keeps on going and you crash into a tree and you die.
oversteer works like this: you drive down the same road, turn but the back keeps on going and you crash into a tree and you die, now oversteer is better because you don't see the tree that's going to kill you"
-richard hammond
Oversteer scares passengers, Understeer scares drivers
Yeah cause the driver in front and the passenger in rear that's u mean right ?
I think it's in the sense that a more experienced driver can easily negate oversteer without going too far out of lane, while understeer forces you to take a wider turn and therefore prolong the time where you're in danger of hitting other cars
Understeer is when your front end hits the wall, oversteer is when your rear end hits the wall, horsepower is how fast you are going when you hit the wall, torque is how far you move the wall when you hit it.
LOL very accurate and brief description of the whole video.
How far you move the wall is a case of F=ma, and has nothing to do with the car's torque haha.
Engineering Explained haha thanks :)
56ratbug I opened the video just to comment this but you were faster hahah
Wise German proverb
56ratbug I thought torque was just how much power was being sent to the wheels?
Im so sad i just found your channelt the other day and i saw you actually just stopped posting recently. Ive only been here but i absolutely love these videos and i feel will really help me prepare for automotive engineering school. All i wanna say is thank you
But Top Gear said that oversteer is better because you don't see the tree that kills you.
Lol
azn310 double lol
BmanUltima "If you go through the pearly gates backwards in a fireball, that's a cool way to die!" - Jeremy Clarkson.
Also,
"Oversteer scares the passengers, understeer scares the driver" - Someone else
Eric D Dude. Racing is what life is about.
phant0 That is only if the driver does not hit that tree =)
I would want to be a passenger in an oversteer car with a good driver, and understeer with a bad one.
SUBSCRIBED! Glad i came across your page again! last time i saw your page you were only about 30k in on subscribers! Glad to see your growth and congrats on the award!
And thank you for providing the community with your videos! I am sure i speak for all when i say you've taught each and everyone of us something new.
Glad you enjoy the videos! Thanks for subscribing!
I love seeing your videos, I basically see them everyday and I learn something new every day. This is awesome!
Good explanation :) You forgot to mention that oversteer also increases heart rate!
revmatch oversteer is also known to cause massive releases of dopamine in the brain
Good thing I actually studied for my biology test in Monday so I know what dopamine is
Yea...science!
+revmatch Understeer your way into a tree has the same effect.
Hello there,
Great videos !! guess there exists another way to reduce under and oversteer
Modern cars brake the wheels individually and induce a yaw moment to correct the Under/Over steer..
Scenario > If you are taking a left turn
1. Understeer > Brake the left rear wheel so that a yaw gets generated to help the car get back on the intended path
When you do this, the amount of utilizable lateral force on the front axle increases >>>> Helping you to get into the curve
2. Oversteer > Brake the front right wheel so that the front axle loses the amount of transferable lateral force >> Induces a understeer to compensate the oversteer and help the vehicle to get back on the intended path....!
Good explanation ! initially for awhile now i've heard some different explanations that actually cause you to get confused. I remember even reading an article where it was easy to misinterpret what they are trying to explain. Before i thought understeer was the opposite of what it actually was until i watched this. Good stuff.
Great explaination of understeer and oversteer! We can all become magnificent race car advisors one day!
Soo is Drifting controlled oversteer?
+Zach Maclean Evidently.
Oversteer is generally unintended and results in a spin. Drifting and power slides (which are the same to my knowledge) happen because a car is prone to oversteer, and is able to be controlled by steering in the opposite direction to prevent spinning out. So yes it is.
Namaste.
THANKS A LOT sir I'm doing automobile engginering and your videos are very very very useful to understand thing's better. If YOU ever come to India PLEASE let us know....my friend's and me are your big fans.
THANK YOU.😇
I like that you used the same tree example as carthrottle!
Great video as always, it would have been even more interesting if you'd have presented it together with the differences between FWD, RWD and AWD :)
may be those videos need to be re-uploaded
Thanks a lot for such helpful video can u explain what active steering is ? it would be a great help
Love your videos and would love to see a video on shock absorber setup in race car and the effects of different settings on adjustable shocks and springs
To get even more technical; maximizing tire load (per condition) can optimize g-force loading, thus helping to achieve the right condition in the right situation. Softer front end--giving some dive--in combination with mild anti-roll can achieve good cornering control while trail-braking, yet keep the car neutral mid corner (actual values dependent on tires).
As I was reading some of the comments...I thought the same thing...factoring in the type of tires in the vehicle have alot to do with the traction and reaction of the vehicle too...
Craig Cundiff Yes, unless the car performs fairly neutral on the limit, unless there is a drastic change in maximum cornering force. Generally, the higher the lateral g-force, the stiffer the spring rates and anti-roll need to be. And vice a versa.
Could you please make a video explaining the benefits of adding spacers to all tires vs front or rear tyres, largest front or rear spacers etc...?
SWEET. Was hoping for this one.
Great video mate. Keep up the good work
If understeer is from too much load on the front, how does downforce on the front help? wouldn't that add to the load?
When you say 'reduce understeer', I'm assuming that you are saying we want to reduce the front slip angle, therefore to reduce the front tire load....so you said 'to reduce understeer, you can increase the front downforce in order to increase front tire load'... i'm not sure you are right about that part. What do you think?
Mingye Yu Increasing downforce at the front increases available grip at the front, hence the vehicle is less likely to understeer.
Can you do a vid to explain why that new Z06 crashed on acceleration, similar to how that M4 did gunning it out of cars and coffee? Was it driver error? Tire temperature? Characteristics of the car? Gear selection? Etc? Most people in the comments of those videos just seem to criticize the drivers but no one seems to actually explain what went wrong with much credibility. Your thoughts would be appreciated, and probably attract quite a few views if you can mention those crashes in the thumbnail/title since they have a lot of views too
SoSickWidit Well I haven't seen the videos you're talking about, but ultimately drivers are the ones in control. If they crash, it's a result of the actions they took (perhaps not understanding the limits of the vehicle). I would anticipate a little too much throttle. :)
Awesome video man!
Hey man, great channel you have here! I drive a 2015 Audi TT-S. Great car, great drivetrain, but it understeers a bit too much. Where do you think I should begin my quest to kill the excessive understeer? Front / rear ARB? Front tires? Thank you.
+Ricardo Lourizela I would start first by trying to increase front traction, rather than inducing oversteer. Maybe playing with the front tire pressure (slightly lower) and camber (slightly more negative) to see if it can drive a bit more neutrally. Then maybe move to the rear arb (or reduce front arb) if necessary.
It's a road car, it's legally required to understeer, and this has much to do with the fact of the weight distribution (CoM location), and cornering stiffness of the tires (matching cornering stiffness to the vertical load on the tire is the critical thing here). Ever notice that 'sport' sedans (M3, S4, etc) have larger, wider tires on the rear axle then on the front? This ensures that the rear axle has a higher cornering stiffness then the front, which is critical to stability, which is important to the legal department of the vehicle manufacturer. In order to reduce understeer in a production vehicle with a greater portion of it's mass resting on the front axle, the larger tire should be placed on the front axle. Changes in camber and tire pressure will have fairly minimal effects (provided the same tire is used on the front and rear axle....hint).
Why you always stop talking when it's make sense in to my head you have the information so do it wright keep talking give us videos when you explain things it make everything easier but you good and I like it even the car review its new revolution that you give us any tiny little things like the under the hood good channel and good information
Thanks Engineering Explained , great vid, now i'm gonna hop on need for speed shift 2 unleashed and tune my FWD cars for a little more oversteer now that I know how to do it lol
If I increase the front toe in would I not have a higher slip angle for the wheel with higher load when I turn and thus increase the lateral force created by the same steering angle?
Nice video.
Could you explain more on chamber and toe..
So the old Preludes with 4 wheel steering, does the movement of the back wheels change the toe or slip angle? Or is not considered changing anything since it's "steering?" Does 4 wheel steering help neutralize things??
Under steer, when you feel like the front wheel is going to hit the barrier around the corner, over steer is when you feel like you are going to slap the rear tire into the barrier .
Hi, in your next video, can you go a little deeper into why adjusting the stiffness of the front/rear anti-roll bar will get you more oversteer/understeer? I recently installed a rear ARB on my subaru but can't figure out the physics here. Thank you so much!
Benny Tang My explanation would be that body roll allows more weight to transfer to the tires of the car on the outside of the turn, more force pushing down on those tires increases friction/grip, if you reduce body roll then a lot of the centripetal force on your car caused by making the turn will not be absorbed by body roll but will be put on your tires horizontally causing them to slip out more easily. You can use this to your advantage, after youve done some engine braking and trail braking to scrub off speed before a turn, try giving the brakes one last hard pump, this will transfer the weight of your car to the front tires allowing them to grip more strongly when you turn the wheel (but you may have to watch out for some oversteer coming out of the corner)
John Doe Force on the tire does not linearly give more grip. You get less increase in grip than the increase in weight due to the rubber giving up. He made a video on this earlier. Because of this, you will get and advantage of having a low centre of gravity and a stiff anti-roll bar.
Benny Tang The reason changing your arb stiffness effects the over/understeer has to do with the steer gradient. The steer gradient is a function of "tire cornering stiffness" so if you increase the stiffness of the front much more than the rear you add understeer. Doing the opposite by increasing the rear much more than the front adds oversteer. That's a short explanation, maybe Jason will expand on this more...???
jfurli what you just described there is exactly what need to know why. Generally an ARB adds more stability to the car, and adding a rear ARB intuitively adds more stability/traction to the rear, which, however, adds oversteer! I need a scientific explanation why a more stable rear end can cause more tail happy oversteer. Shouldn't it happen the other way around?
Benny Tang I am going to interpret your definition of "stability" to mean less load transfer to the rear of the vehicle but the front would be able to experience more load transfer. This increase in the weight on the front of the vehicle is what causes the oversteer just like Jason explained in his video.
What cause the slip angle difference between tires of front and rear axle. For example in understeer scenario the tires at rear axle experience less slip angle than front. Is it because the lateral force resistance is low at front axle tires due to less weight at front???
Understeer is when the front of your car hits the wall. Oversteer is when the back of your car hits the wall. Torque is how far you take the wall with you.
Gasinduced I wish people would stop saying this. The only thing that affects how far the wall travels (and let's be honsest, most of the time they're far more rigid than your car, and the wall will remain stationary while your car crumples) is the mass of your car and the speed at which you're traveling.
Engineering Explained Seriously!...however, in their defense, more torque = more horsepower = more speed which in turn does effect how far you are taking the wall with you. (it is just that the difference is probably much less for the wall and alot more for you and your car)
Am I right in thinking that softening the ARB on one end gives more grip on that particular end without taking away grip from the other end? If so, then surely it's preferable to soften the ARB where you lack grip rather than stiffen it on the opposite side thus giving you better balance and more grip overall?
I believe it's also solely on the application... for AWD (WRX 16) owner here... To reduce understeer we put a larger/stiffer ARB on the front to prevent less body roll on the front side giving more contact touch to both tires = more traction. At the same time, if we put an ARB too Stiff in the back it'll make it come out more... again for Subies but I would believe this would be similar to other applications.
I have some issues regarding the roll axis inclination... We are designing our atv for oversteer...I have gone through lots of articles and forums and have found that the rear roll centre should be below the front roll centre....but at the same time I've come across some articles which says that the rear roll centre should be above than front roll centre...
please guide me
You should do a video about Water/Methanol injection!
For a Baja sae car, would oversteer be better since were only going 30 mph? Also, could we achieve that by having the rear toe out during bump?
just a little point. Oversteer wont really get you to go around a corner more quickly like the green arrow implies. Oversteer is only really a benefit on something like a hairpin where you need to "flick" the car
brad ley Correct, perhaps I didn't make it abundantly clear but I was trying to imply the back would kick out and you would spin around (with significant oversteer).
Yup.
Ps- fricken love your channel.
So if you reduce toe in to reduce understeer does that mean toe out is a good setting to reduce understeer?
Can you explain how spool differential affect under and oversteer
I find my Audi a1 increases under steer dramatically when psi is below 33 (recommended 38).
Hi i love your videos you have gained a sub...Keep it up :)
Why does adding downforce decrease understeer? Isn't slip angle proportionate to the normal force/weight, and thus proportionate to downforce? (Same goes for oversteer btw)
wouldn't it be like when you increase the front downforce the split angle for front will increase causing an increased understeer? But you said it'll reduce the understeer. Will you explain me how would it will decrease understeer?
Wouldn't slowing down as you approach the cureve help reduce or eliminate both problems?
Hey can u explain how G force is considered and how to calculate it?
can you please explain why there is larger front track wrt rear in some vehicles
doesn't this also play a part in different drive trains of vehicles too? rwd fwd awd ?
Oversteer scares passengers
Understeer scares the driver
Than you for the great info as always :) I just have one question, my car is FWD and I am bit confused to set a staggered wheels (wider in rear, maybe 8 in front and 9 in rear), would that be OK??
how do you correct understeer in RWD car ? oversteer is much more easier to recover
Wouldn't an increase in the load on the front axle actually increase understeer? Since an increase of the load automatically increases the tyre's desire for more slip angle this would mean that as a result the slip angle of the front tyre will be greater than before and therefore it would be a step towards more understeer. Please someone correct me if the logic is wrong
question/new video idea: how does weight balance influence handing? why a lot of weight over the front axle makes the car understeer (let's say an audi) when even no weight over the same front axle makes the car understeer too (let's say an early 911)?
what about stiffening the front absorber ? will that reduce understeer ?
Oversteer scares the passenger, understeer scares the driver.
What about: strut bar, front lower tie bar (not anti roll bar), rear lower tie bar and something like a H brace in the middle of the car?
mrbigtian If your chassis isn't very rigid some of these can improve steering dynamics, but it won't be quite as significant as the other factors unless the chassis is super flexible (which it more than likely won't be).
Engineering Explained so should I buy those for my 09 Si or it would be a waste of money?
what is the frame behind u on the wall beside the board ?
Wrecked my car couple weeks ago, spun around and landed on the side
More than half the value of the car to repair
Unexpected oversteer is no fun
Bugside almighty Unlucky! Similar thing happened to me as I was driving home months ago. Luckily I managed to correct it as much as I could and only clipped a fence at the side of the road.. few deep scrapes and small dents in the sideskirt! :(
Slow down out there. I'm sure they teach that in Drivers Ed
i have a exam soon thanks alot this heloed alot
I never understood this, if friction force is equal to the mu * the normal force, how can wider tires be more beneficial towards gripping and steering on the road? I was wonder why you see a lot of race cars and dragsters with massively wide tires and looked it up to find that its not the width that adds friction, its that the tires are stickier/softer, and the width compensates adding stability to the tire itself. So how can simply wider tires in the front/rear help reduce understeer/oversteer?
John Doe In a nutshell, understeer happen when your front tires have more than they can handle, and oversteer is the same thing but for rear... by giving wider tires (more surface area, more contact patch), it gives more juice to the tires to handle more. again, as the video explained towards the end, there are MANY things you can do to change the behavior.
Personally, instead of just increase the tire width, I'd suggest you first go with strut bars, sway bars, or spring rate. Since in most cases (for DD), if you increase your tire width in the front, you would want to also increase it at the back too, and if you do that, your under/over steer characteristic remain would unchange. Unless you drive a race purposed car, in that case you could run different sizes tires between front and rear.
***** See what i typed above.
totszwai I see what youre getting at, but what I mean is that (bare with me im just a senior in AP physics, I know this stuff gets way more complicated) the force of friction stays the same no matter what the surface area is, so wider tires shouldnt really make a difference as long as the normal force and coefficient of friction stay the same
John Doe Wider tires allow the use of softer compounds which gives better traction/grip. Narrow tires need harder compounds to support the sidewalls. A fat tires has stiffer sidewalls and can use softer rubber.
John Doe Mr. John Doe, I thought you were shot by Brad Pitts because of his sin "Wrath".
Mice vido man keep up the good work can you make a video about forged wheels vs cast wheels
Nice
Hey Love your videos but i have trouble understading toe in and toe out characteristics can you help me. That whoud be awesome. And Keep up the good work.
Nick Frazer ua-cam.com/video/83_GTZeuF6M/v-deo.html
Engineering Explained I have all ready wacth it but here you say that reducing toe in on front tires help to reduce understeer for your other vid you say that front tire toe in helps car handling if the car is rwd if its fwd its toe out that benefits that confused me a litte bit what did i miss thanks for the help and what set up is used in awd cars ?
Engineering Explained I have all ready wacth it but here you say that reducing toe in on front tires help to reduce understeer in your other vid that is explaining toe in and toe out you say that front tire toe in helps car handling if the car is rwd if its fwd its toe out that benefits that confused me a litte bit what did i miss thanks for the help and what set up is used in awd cars ?
So, technically, Oversteer is the Understeer of the rear tires? They still want to go foward while the front tires want to turn, opposite of Understeer.
What mods can u do to help under/over steer...a front and rear strut brace?
***** Only if the chassis is considerably flexible. I explain at the end the adjustments you can make to influence the steering dynamics.
can u explain how to set oversteer in a car
I heard a that a very well placed splitter should erase understeer. I wonder is that is true
xxxSpetnaz It can help add downforce to the front, which would be beneficial if you're understeering.
But wouldn't too much down force affect the suspension?
xxxSpetnaz There is no way to get too much downforce on a normal road car. It will never get near the type of force of a small hump.
Understeer sucks mostly going downhill on winding mountain roads. RWD always does feel more natural to me though. I feel more safe and confident knowing the limits of tire slippage in RWD cars, while FWD just still feels weird to me.
My Massey Ferguson 165 suffers understeer. How can I help this ?
Shouldn't we REDUCE the front downforce to reduce Understeer? 2:40
aint nobody got time for undesteer.
No one should be over/under steering now, every car has VDC.
Why do AWD cars generally understeer than RWD cars, which usually oversteer more. I know they are exceptions, but in general why do AWD cars understeer more than RWD cars, even though they should actually provide better traction?
+SIMcityplayer2002 Because it breaks the limit of traction for a tyre. A normal tyre has roughly a max grip of +/-1G and tyres use that force for a number of things. In an AWD vehicle, the rear tyres are using the grip (G's) to accelerate or decelerate, whereas the front have to share that grip of acceleration/deceleration WITH steering the vehicle. If power distribution is even in an AWD, you will always get understeer simply because the grip of the front tyres gets maxed out.
oversteer is fun
understeer is safe
neutral is fast
How to understeer or oversteer on command?
The reason why we use understeer is that the car has a more predictable behavior right?
So... Which is faster?
The speed of it depends on many different factors. The speed of the car, the traction, blah blah blah. If it's a sharper corner, then oversteer is faster because of less breaking needed, and under steer is probably as fast or faster in a shallow corner. But in real life you'd want neither, and would try to find the apex of a turn and keep as much traction as possible.
Oversteer is when the passenger shits himself. Understeer is when the driver shits himself.
Having both oversteer and understeer is the total nightmare.......hahaha
Alexand21 Though not that uncommon. Most cars will understeer at turn in, and depending on the set-up oversteer becomes more of a problem while exiting the corner.
Have you ever made a vid of how the 'wankel engine' works?
Scott
Oversteer: you won't see the tree that kills you
Misleading thumbnail...
Dadul Ludad Accurate title...
Dadul Ludad Understeer or Oversteer will ultimately lead to what you see in the thunbnail..........
totszwai That's what I thought. :)
yeah I too thought he is going to explain things by showing wheels in the car,I didn't expect complete blackboard teaching
Could you possibly recommend a car to someone who is just getting their license?
Phalanx Gaming 2008 Hyundai Accent. Or any 3rd gen Accent will do.
Phalanx Gaming bmw e36 320i, i got one yer a go when i got my license. It has lots of room and featuresit is realy easy and nice to drive
manager96ful that car is rwd, not everyone wants to get suprised by rear end breaking loose.
DevasionX if you are driving at speed limit it will not oversteer. i had find out that it likes to understeer when it is in limist. cars are designed to understeer. put it overstrees at snow.
manager96ful I see E36s oversteering all the time on touristenfahrten crash videos. Older BMWs have very high rear spring rates compared to the front. For example my E30 has 4kg/mm rear springs from the factory, while the fronts are in the 2.5kg/mm range or so. The front anti-roll bar being larger helps to keep this somewhat balanced, but having the rear springs stiffer than the front creates oversteer balance.
So a strut bar in the front will make my car understeer more?
Bart Van Riel Stiffer anti-roll* bar.
Engineering Explained that's what I meant but does it?
Bart Van Riel Yes
Kordril thanks
Bruh in Forza Horizon 3,I put a Camaro or some kind of muscle car engine inside a 1940 Ford coupe,the thing can't even make it around corners without oversteering.Meanwhile,I have a 1949 Mercury Coupe,doesn't even do anything.
Don't agree with the actual path on the oversteer drawing. If you're going fast enough to make oversteer then you are going to run wide in oversteer as well as understeer. Oversteer does not make you turn a smaller radius than intended.
sky17 Actually great point haha, perhaps misleading for some cases. The goal wasn't to show that the car is capable of a sharper turn, but rather it would be much more prone to spin out. Without counter-steering, the car will not continue to face the intended path, but rather towards the inside of the corner. The actual path will be based on how the oversteer is initiated and at what speed it occurs, as well as how the driver reacts through steering input.
Its called daja vu
Just wondering. Wouldn't slowing down a little on public roads reduce both understeer and oversteer? Take the turns at a speed that the car can handle, and that the driver too can handle. And guess what, it doesn't cost any modifications to the car, plus you'll save gas.
Yes, staying within the limits of the car will result in neutral steering. This video is more emphasized towards track driving where ideally cornering occurs nearly at the limit of the vehicle's traction.
Moi MacArt Obviously cornering at slow speeds will reduce these effects on dry roads, but in adverse weather conditions being able to control the vehicle when either occurs is a matter of safety.
Many drivers are unaware of these effects entirely, and as a result traction and stability control are a necessity.
In areas with snow or ice, lack of lateral grip can only be counteracted by coming to a complete stop in certain situations.
Engineering Explained Hi, it's what I figured out. It's why I mentioned on public roads. Still a good video and a good explanation.
TheZigZagg True. It is why we usually need to drive for the conditions. In adverse weather conditions there is only one secret, to slow down. That said. It is true that anything can happen even at low speeds. And it is a good thing to understand what is explained in this video.
Moi MacArt the truth has been spoken.
OK... now do it for 4 wheel steer.
Or you could just use left foot braking
CLV$$Y haha is this a joke? I only ask because I saw an aol headline that encouraged left foot braking and thought "how stupid is that"....but if youre serious elaborate please
John Doe is not a joke, it depends on your situation, but take FWD car for example, if you are understeering, the amount of weight bias is shifted to the front, causing your front tire to have more load than it can handle. By using left foot braking (while also keeping some throttle opened), you essentially applying your brakes WHILE trying to accelerate at the same time. This in turn makes your rear wheels brakes a bit more than your front wheels, which in turns making less weight transfer to the front, which in turn giving some breathing room for your front tires.
In addition, using left foot braking, you can also keep your rev a bit higher to stay within your powerband, so when you exit the corner, you will be at the sweet spot where the engine makes the most power...
With that said, left foot braking takes lots of practice and needs getting use to. For starter, because your left foot is not used to the pressure, you will normally end up applying too much pressure on the brake pedal, and could be quite dangerous.
There are other use of left foot braking as well, you can Google them up or check them out here: en.wikipedia.org/wiki/Left-foot_braking
Personally, I configured my FWD to be a tiny bit of understeer, and just throttle lift to make it neutral (would oversteer in the rain). Is more fun and easier to drive as DD.
And then there is AWD with random switches between understeer and oversteer, followed by violent death.
Half a joke here. It takes much more time and distance to stabilise it though.
Looks like you gotta little bit of sun!
Jeremy Unfortunately it's how UA-cam compresses the video. It looks much more normal prior to uploading, then boom, an orangish tint.
Engineering Explained its alright you still look good ;)
oversteer isnt always better, NOT EVERYONE WANTS TO DRIFT. There are people who doesnt like oversteering and you have people who THINK its fun and end up wrapping your car around a pole SIDEWAYS, with little to no crumple zone... So many bmw drivers in my country died in sideway crashes.... all morons who just got their licence and watched too much FF and played too much N4S
Basically
Understeer= ur fucked/not good
Oversteer= Drift/ what you want to be cool
Correct?!?!
Forza horizon players any1 ?
They both suck. You want the car to feel like it's on rails
JimmyEG1 Ford Focus, is fwd not is locked on the road by its excelent suspension
This is pretty much incoherent and useless. Oversteer is what my parents' brand new 1968 Buick did to me the first time I drove it. Went around a residential corner to the right, eased up on the steering wheel so it would slip through my fingers to let the car straighten out on the new street. Car just kept turning to the right, almost up on the neighbor's lawn. Had to steer it out of turns, unlike the old Buicks and Chevvies I always driven.
Wtf are the words coming out of his mouth
Nope....sorry; probably an excellent engineer, but this young fellow talks like 99.9% of engineers I've EVER encountered: way too technical. But, on the other hand, this is an "EE" episode.