Why Threshold Braking Is Impossible - ABS Wins!

Is Threshold Braking Better Than Anti-Lock Braking Systems (ABS)?
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There's a common misconception in car world that "threshold braking" is the be-all and end-all of performance braking, and that systems like ABS cause you to have longer stopping distances. Such is the hubris of a car enthusiast, who believes they are Lewis Hamilton (or Nicholas Latifi, whoever you prefer), nay they are better, and thus they don't need such aids like Anti-Lock Braking Systems slowing them down.
True, if you car doesn't have ABS, you better learn to perfect your threshold braking technique, because it's all you have. But if you drive a modern car with ABS, it's going to outperform your braking time and time again. Don't believe me? Watch!
References:
SAE J2246 - www.sae.org/standards/content...
2000 Study - journals.sagepub.com/doi/10.3...
2010 Study - saemobilus.sae.org/content/20...
2018 Study - www.sae.org/publications/tech...
10-14x/Sec - www.ijraset.com/fileserve.php...
Honda 100x/Sec - www.hondainfocenter.com/Share...
Slip Plot - www.sciencedirect.com/science...
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[@thedownwardmachine]

I think I see what you’re saying. We need to start having four brake pedals, one for each wheel, so we can modulate them individually.

[@raghav265]

That makes total sense!

[@AlexanderGee]

Four buttons on the steering wheel and you still get to use your thumb to scratch your nose.

[@thedownwardmachine]

In fact, f*ck everything, we're doing five pedals

[@fi4re]

General Kenobi!

[@mind.hacker9996]

and have 2 throttles 1 for adjusting air intake and one for fuel

[@rzerobzero]

This is the closest I've seen Jason to furious than ever before. Some Threshold Brake proselytizer must have really pissed him off.

[@F0XD1E]

There's definitely some "I FEEL LIKE I'M TAKING CRAZY PILLS!" energy here 😂

[@Granchango]

I hear it somewhat frequently, usually from guys who have never even driven a parade lap around a racetrack.

[@dbeckMSP]

you should see the lead gas one, that one is amazing

[@tractioncontroldelete]

You should see him talk about lead in aircraft fuel 👀

[@AlexSchendel]

I think he was a little closer on the leaded gasoline one haha

[@patjackson1657]

My first experience with an ABS equipped 53" tandem trailer was an eye popping experience. Moderate grade down hill, stop light at bottom, and way slipperier than I thought. I knew from experience that I would be unable to stop before the light, and excessive braking would cause a jacknife. I laid on the horn as I explored my brakes, and was astonished when the whole unit stopped well back from the light, trailer dead straight.

[@donperegrine922]

Hahha must have felt a little silly, honking like an out-of-control freight truck just to come to a stop at a very safe distance. I love the story though! I had something similar.....shook me! Emotionsly and also....you know....physically shook me!

[@patjackson1657]

@@donperegrine922 Yes it was embarrassing! Still a good feeling though.

[@MrMice...]

53 inch? 😁

[@patjackson1657]

@@MrMice... good catch. My excuse us "fat fingers!"

[@MrMice...]

@@patjackson1657 all good, just "bustin' chops" 👍

[@GothaRsk]

14:50 I am glad you mentioned this. I had a car without ABS until 2019, I practiced threshold braking and was able to brake steadily without locking my wheels. And yet when I later got into emergency situation (car in front of me started braking because deer jumped in front of it), I was just sliding to it. Luckily I had enough distance to stop and not hit the car. Then this year I had another emergency when a car didn't give me the right of way. I again just pressed the brake pedal as hard as I could, but now in a car with ABS and ESP I was able to steer and not hit the other car. Without ABS I would just slide into it.

[@charlesrodriguez7984]

Only vehicle i practice threshold braking on is a bicycle. Very interesting though.

[@imnota]

That's the biggest advantage of ABS, no matter how good you are at threshold braking, when you have some emergency situation you're just gonna mash the pedal like a dumbass, and ABS is gonna save your ass.

[@Rollin8.0]

@@imnota you are 1000% correct

[@Eric-zs6rd]

Because different roads have different coefficients of friction, practice with threshold braking on one road is meaningless if you're on a different road. Or if it rained, or if the temperatures changed, etc.

[@danielkinton7193]

@@imnota I was in my dads 70's car after a light rain going down hill to a traffic light, just sliding into the cars until I remembered to let off the brake and the front wheals caught and threw me in the ditch with like 10 ft to spare. It was a big ditch, and a really heavy door at a 35 degree angle. The car was fine after a pull out of the ditch, and I have no idea if any of the cars in front knew how close they were to getting hit.

[@MyHandleIsGood]

My car came with ABS as an optional extra. Unfortunately the buyer didn't pay for ABS, fortunately though, the brakes are so bad that they don't lock up at all.

[@thomasrogers8239]

That's a problem not a feature

[@MikeR65]

My old Chrysler Town and Country was like that.

[@mattv5281]

Sounds like you have Neverlock Brakes

[@geemy9675]

until you have low traction

[@electus1]

🤣

[@garyandtricia1]

100%. Even if you could react fast enough, you can't control wheels individually.

[@BeamRider100]

Yeah but big deal one wheel locks up momentarily for a metre.

[@rkan2]

@@BeamRider100 Difference between life and death tbh..

[@motioncompensation1544]

One foot can't modulate the braking power for four wheels

[@bingoberra18]

@Random Doesn´t even need to be different surfaces, the fact that you unload certain tires and load others more entering a corner means there is already a risk of lockup, which easily leads to flatspots on the tires.

[@Coconut_54]

Unless you put 4 brake pedals in your car :D

[@richsoule]

Every day you learn something is a good day. Today, I learned that what I've been telling my HPDE students is false (unless they happened to have a very old ABS-equipped car). Which means my future students will also learn something. Learning is good. Thanks Jason!

[@bigbadwrastler22]

I suggest you tell the students to do skid pad testing before throwing it into a corner with ABS on

[@uncreativename9936]

@@bigbadwrastler22 yep, a lot of commuter cars have HORRIBLE ABS. I used to have a nissan versa and if ABS activated while I was going in a straight line, the car would start swerving in the lane because it would pull so much power from one corner, but not the other. I'm sure performance cars are much better, but like you said test it out first.

[@krism3600]

The biggest revelation for me was that the ideal grip percentage doesn't occur right at 0%. I always thought static friction coefficients were necessarily higher than kinetic friction coefficients (meaning that the highest friction occurs when there is no relative movement between the two surfaces) but I guess that was an oversimplification. Mind = blown! Great video!

[@pyRoy6]

The second biggest revelation for me was that ABS is not wildly fluctuating between near-0 and near-100. I think I must have seen some slo-motion video of ABS in action, and my brain go the impression that the wheel was fluctuating between fully-locked and near-0 braking.

[@brianwright9514]

Tires need slip (deformation) to create force.

[@xtnuser5338]

The extra friction comes from shearing rubber. Up to a point (ie. before the tire starts sliding completely) you're still getting the regular amount of friction PLUS a bit extra because of the shearing.

[@Delibro]

I think you would be completely right if the tires were solid, then 0 % slip would be the optimum.

[@brianwright9514]

@@Delibro that's actually incorrect. Tires produce zero traction without slip. That's actually one reason solid tires are worse then pneumatic tires. But even solid tires deform. Just not as well as pneumatic tires do.

[@DandDClark]

I think that in addition to the ONE TIME that you are going to press the brake, you are probably going to be panicked, which means you are not focusing on the threshold braking, like the system will! Great video Jason! Makes total sense to any one that has any!!

[@RhodokTribesman]

People say this but ehhhh, I was focused enough during a near crash to heel-toe down during braking. If you practice sport driving, regular road stuff is a lot more tame.

[@danbert8]

The key there is to practice emergency and hard braking regularly so you keep control of the car subconsciously. Also, oversteer/understeer situations.

[@chitlitlah]

@@RhodokTribesman That supports the OP. If you were in a near crash situation and spending part of your focus on downshifting, you weren't focused on the right things.

[@RhodokTribesman]

@@chitlitlah focused on the danger and surroundings AKA cognisant under stress. I was unaware that keeping your cool is a bad thing.

[@ikocheratcr]

One can train, I used to have a old car that had no ABS, threshold braking was my best option. I do not miss that at all, once I experienced ABS, wow, no going back.

[@phant0]

My previous two cars were a a 2002 and 2006 Subarus. Both of them were downright dangerous in snowy/icy conditions with the ABS on. The ABS would completely overreact and cut nearly all braking power as soon as one wheel was on a patch of ice. After it nearly sent me across a busy intersection, only saving myself by the very last centimeter by using the e-brake, I started pulling out the ABS fuse for the winter. The difference in braking distance on partially icy surfaces was very noticeable. However I now have a '15 Subaru that does not have this problem at all. It really looks like all ABS are not born equal. A shitty ABS system can truly be worse than threshold braking.

[@CesiumSalami]

HA! I just wrote a reply saying exactly the same thing! Crazy that we had the same experience. My 2002 Subaru WRX was terrifying in anything by warm, flat, dry pavement. Exactly as you observed it seemed like if one tire struggled, it would take down the whole system. I just pulled the fuse year-round because, like with the snow performance, if there was a bump or dirt patch on dry pavement, you'd get the same issue, which seemed like taking braking power down to almost zero. I had a super close call due to this in the dry and gave up on the system entirely. Which was super sketchy, because I had to remember to pull the fuse again after oil changes (or remember to replace it prior) and notify anyone driving the car that it didn't have ABS. I think it was very car specific. My 2005 Subaru STi didn't have any of these issues, FWIW.

[@tarkanyibalazs]

My 2001 wrx does the same thing. They were simply not built for ABS use, but rallying, where you don’t really give a dime if a wheel locks up for a few fractions of a second, you plow thorugh the corners. Even modern WRC cars still don’t use ABS - though for a very different reason whatsoever.

[@Sleggt]

Yep, early-mid 2000s Subaru ABS is borderline dangerous in snowy conditions

[@vilbenasvienuolis]

07 outback on gravel has the same problem. But i left the fuse in. Control is more important

[@CesiumSalami]

@@vilbenasvienuolis I don't fault the decision to leave the fuse in, but I sort of think it may have been different in your case. This loss of braking was astonishing on some models. So far from the limit of traction that it didn't require special attention / skill to easily beat ABS without any slippage or locking up a single wheel - in some cases with the ABS on braking wasn't much different from just rolling to a stop. It may have been really car specific. I had a 1998 Legacy, 2010 Forester, 2005 STi - where the ABS was fine. The 2002 WRX was singular unique in its abysmal performance.

[@macaalf8219]

had this ABS discussion for years now. The first systems increased the breaking distance slightly but remaining to be in control of the car was deemed more important then. AFAIK: One of the main problems with drivers is that they actually do not break hard enough or let go of the pedal when the car starts rattling under ABS.

[@LOGIBEAR01]

I find steering under abs sucks in icy conditions. Using over steer and the throttle pedal have been much more efficient for avoiding obstacles. Obstacle avoidance is much more than breaking.

[@alyx6427]

yeah, i think modern cars will almost make you brake hard, if you suddenly put a bit of braking force it assumes you want full braking force

[@zoltanv7289]

Most cars (even my 06' minivan) have an emergency function, so when it detects that I started braking suddenly and with quiet a big force (my car, others might use other methods) it boosts the brake as much as it can, so basically my foot unintentionnaly starts braking 100%, instead of lets say my self in shock who would only brake with 60% force. I guess its an early system, but works fine, on a very basic principle: you brake more if the brake pedal is lighter than what you are used to. It used to europes safest car for a year, until the same manufacturer came up with the bigger brother model. Side note: the brakes are fine, it just passed inspection 2 month ago, this is intentional, its a system on the car and its not that my brake pedal falls in. It has fine brake pressure, it has new discs and pads all around, bled out and everything!

[@CycloneCyd]

As a Professional Automotive Engineer of 40 years AND an ex rally driver and rally car builder I 1000% agre e with this analysis. On top of that, I refer you to a study from 1989: A group of 10 rally drivers from Oxfordshire went on a rally driving course at Manby, Lincolnshire. Some of us took our own rally cars along on the day as well as using the provided Escort mk2 rally car. One of the chaps went in his road car - an Audi Quatro Coupe. Back in those early days these Audis had an ABS off switch. So we set up a course and all 11 of us (incl the instructor - a National Rally Champion) had a game of 'beat the ABS'. We all had 3 goes each - not one of us beat the ABS even one single time. For something like 2 1/2 decades now I've been arguing this on one forum or another (starting on Honest Johns Backroom forum in the 90s) using the 4ch/1ch and modulation frequency arguments. And quoting my experience from above (along with other experiences from my professional life). I always got shouted down by the bar room engineers. At least now I've got your video to back me up. The bottom line is that since the early 90s no human driver has been able to beat ABS *_except on snow or gravel_*

[@MarkShank]

This is going to start many arguments. Families are going to be broken up!

[@LikelyCandidate]

I sense a little trolling for engagement vibe on this one. Relying on us to trigger the algorithm like a panicked driver triggering ABS.

[@keithmcdonnell4485]

As your little disclaimer said on the screen, old abs systems were more of an on /off switch type of system and they were not as good as an experienced driver doing threshold braking... but they WERE better than a panicked driver slamming the brake pedal to the floor. Subaru ABS had a horrible problem on low friction surfaces to the point that panic braking was actually better than Subaru ABS on ice and snow. Modern ABS is more like electronic brake force distribution. My 2005 EVO had electronic brake force distribution and i think a separate ABS system. I assume that in modern systems these two are integrated together into one system. I hope that Subaru has fixed the ice and snow ABS problem.

[@MegaLs2000]

Do modern ABS still shake the pedal when you brake? Haven't hit abs in so long now.

[@gaborb]

@@MegaLs2000 yes. excpet the real modern ones :) (2-3 year old cars might have it)

[@scottmcqueen3964]

Yea, and they didn't all control the wheels individually too. All the 90's Nissans for example only had 1 line for both rear brakes.

[@SivaKanthSharma]

@@MegaLs2000 the way it was explained to me, that vibration is the abs pump kicking in and out, modulating your brake pressure.

[@macroman91]

Regarding "brake bias" - you should look up a height adjusting proportioning valve. It's a valve attached to the suspension which regulates rear brake pressure in proportion to the weight on the tires.

[@636theofthebeast8]

This is even more true with motorcycles, since they get massive weight transfer under heavy braking. You can pretty much get to 100% weight on the front wheel during maximum braking. For this reason, you have to progressively squeeze the lever even during an emergency, to allow time for more weight to transfer to the front tire which allows for a heavier braking force without slipping. ABS is a huge game changer on 2 wheels.

[@jamesleonardpanes9915]

bicycles can exceed 100% weight transfer under emergency braking conditions. That results in a flip over the handlebars. An experienced cyclist will get off the seat and crouch behind it to reduce braking distance. I would think that ABS prevents this from happening on a motorcycle.

[@SivaKanthSharma]

@@jamesleonardpanes9915 that’s not exceeding 100% weight, it’s locking up your brakes without losing tire grip, so instead of the tire rotating, it’s the whole cycle that’s rotating. Yes, it can happen on bikes too, but as I defined above, you need really good tire grip for that to happen. Less likely than on cycles.

[@surferdude4487]

@@SivaKanthSharma On a racing bicycle, the normal riding position has the torso bent down over the handlebars. This already puts more than 50% of the weight over the front wheel. It doesn't take that much grip to place the centre of gravity beyond the front wheel. That's why it's a good idea to get off the saddle and shift to the rear under emergency braking. ABS would certainly help, but when the whole vehicle weighs less than 9 kg, people are not enthusiastic about adding any weight. Motorcycles are considerably heavier and they have a much higher power to weight ratio. The added safety from a good ABS would likely be worth the extra weight and complexity.

[@MegaDarkTroll]

FortNine has an amazing video about that if anyone's interested

[@Rick-nj2pi]

Keep up the excellent job. Love how you "break" down the science to a simple explanation. Also, even though you are producing less often...I'm enjoying them more. Maybe just me but the quality is going up and seeing more of the passion of the engineering again in you in the videos...may also be the reason why I'm enjoying them more or think the quality is better. As an engineer, your passion for engineering shows. Whatever changes you made in your life between producing videos, keep it up...it shows positively.

[@EngineeringExplained]

Thanks for all of the positive remarks here, really appreciate it! :)

[@Kavafy]

yeah it's an excellent brakedown

[@rmksledhead63]

Glad you mentioned the gravel braking. My S10 slowed down much better on gravel after the wheel speed sensors died.

[@pontiacg445]

My old 99 S10 would pop the abs if you turned off a road and up an incline to get into a parking lot or similar, something to do with loading the suspension hard, not even on the brakes hard. Pretty much leaves you careening straight at someone's driver's door, scary stuff. Even if a single wheel would lock (and it probably didn't in the first place) it'd effectively kill all the brakes with how slow it cycled. Garbage 90's systems, I cut that crap out of the truck when I had it.

[@bigglyguy8429]

I had to kill the ABS on a rented Jimny cos it literally could not slow down on a gravel hill.

[@JCintheBCC]

This is (one reason) why dual sport motorcycles allow the user to disable rear tire ABS on the bike.

[@RideGasGas]

No question ABS wins. One interesting observation is that during the braking exercises at an AMG Academy event I attended, which used the E63s AMG with Carbon Ceramic brakes, initially most people did not fully press the brake peddle enough to get ABS completely engaged. I've seen this at several different events. The average person doesn't want to lock the brakes. They are either afraid of locking the brakes and losing control, or they are afraid of hurting the car. Another interesting aspect of the braking exercises I've experienced at Mercedes, BMW, and Audi sports car training classes is fully engaging the ABS while in a turn. As a 60 something guy who grew up without ABS, jamming on the brakes to the max in the middle of a turn is not something that comes naturally - we learned early that this was a really bad idea. However, every modern ABS equipped car I've done these exercises with is drama free during this exercise. The car tracks through the turn allowing you to continue to steer to avoid obstacles while at the same time braking at the maximum rate. In addition to driving cars on the track and off road and in snow and ice conditions, I also used to road race motorcycles. I still ride off road and one of the bikes I have (KTM 1990 Adventure R) has anti-lock brakes. Such an amazing thing when riding on loose terrain. My KTM EXC 500 is old school as is my GasGas trials bike so I still have to have some manual braking skills to get by. But for me ABS is pretty darn cool.

[@iamnotunusual]

At a similar Toyota/Lexus event, they were very clear, mash the break pedal as hard as you possibly can if you want to stop in the shortest possible difference.

[@rundownaxe]

@@iamnotunusual My 4Runner has an emergency brake feature that caught me by surprise a few times. If you go from throttle to hard braking in a very short time the brakes will go full power on their own. Looks like Toyota made sure you used all the brakes when you needed them. It stops that big SUV surprisingly quickly.

[@compu85]

Also, since the late 90s a feature called "emergency brake force distribution" has been available. When the car senses a panic stop it applies the pedal *more* for you. On some cars this is internal to the booster (you can feel the pedal dip away from your foot!), on others it's internal to the ABS unit.

[@stormatron6184]

"Emergency brake force distribution" usually refers to the ability of the ABS system to brake individual wheels (distribution). The pedal moving away from your foot is probably the ABS system lowering the pressure of the system to prevent a lock up. The brake pads experience the same reduction of force from the system as your foot does. It won't give you uncommanded braking.

[@d47000]

@@stormatron6184 The original commenter is actually right, on a lot of cars this is a feature coded into the ABS module. In the German cars it usually comes in, people tend to underestimate the pedal force and travel it takes to reach full braking potential. It will detect a panic stop and the ABS module will command full possible braking pressure even if the driver has not applied sufficient pedal force. I usually disable this feature in my BMWs to achieve a more linear brake pedal for track driving, but it's definitely a great safety feature if you're like most people and don't often slam the brakes hard enough to trigger antilock

[@stormatron6184]

@@d47000 What possible logic could the designers use to determine a "panic stop" rather than anything else? I could see an option to change brake pedal linearity like a game controller being possible. E.g. 50% pedal is 65% braking ability. But it still requires you to push the pedal to that point and it's the same every time. You still only get as much braking as you push the pedal for.

[@d47000]

@@stormatron6184 In the more modern BMWs whose stability control logic I am pretty familiar with, the ABS module (as part of the "Hydraulic Brake Assist" program) monitors ground speed, brake pedal pressure, and rate of deceleration to understand when the car is in an emergency braking situation. At this point it increases brake pedal pressure to the point of antilock activation. Let's say if you were to very gently and smoothly press the brake pedal until it reaches ABS threshold, the brake assist program would not kick in. German cars tend to use pretty advanced software algorithms for this type of thing.

[@dwindeyer]

@@stormatron6184 In my car (2010 Lexus IS 250 RWD) the emergency condition that boosts the brakes is detected by using a forward facing radar. It's only supposed to activate if there is an imminent collision.

[@RottnRobbie]

It certainly was possible to beat some older systems... Sometime in the early 80s (before most people had any experience with ABS) I took a high-performance driving course. One of the exercises they had us do was braking in a straight line with ABS, then obstacle avoidance with ABS. They then disabled the ABS by pulling the fuse and had us do the same things in the same car. In the straight-line stop, I was able to stop significantly shorter than with ABS. But in the avoidance manouver, the computer won, by quite a bit!

[@kitsandham7001]

Yeah absolutely, I could easily outbrake my 89 Toyota Celica’s ABS, but in a sudden avoidance situation it was great for that moment before full situational awareness.

[@zachsoanes6417]

My dad humbled me when i was a teen with this, glad he did taught me to respect the car alot more as a teen.

[@Martink9191]

years ago I had first year Opel omega B (1994), it had ABS but only ONE brakeline for both rear calipers. And it was factory setup. I assume, that when one rear wheel locked, abs cut out both rear tyres. So thats why human won in this situation.

[@elek101]

@@Martink9191 The rear wheels arent doing much anyway during braking

[@MrHaggyy]

@Martink9191 the rear never brakes to the fullest. A lookup at the front does not change the direction of the car. It only reduces the amount you can brake. A lookup at the rear will always spin the car. In the slipchart your ABS keeps the front close to the peak slip-grip. The rear is on the rising slip curvature and wont get higher than a certain threshold. You will gain a view cm of brakedistance under ideal conditions. Your reaction time is 10-100x times more relevant and you don't need to worry about unwanted direction changes. You even have the ability to slightly turn the car. Something that your tires can't do under maximum braking.

[@SpottedCreeper]

There's a reason why regulators in EU in 2004 (and loads of other countries in the last decade) made it compulsory for all new vehicles to have ABS - it saves lives, people stop better with it. Sure, Mr Racer guy might be pretty good at getting his Focus ST stopped when he's concentrating, but Auntie Mildred driving home from the shops in the rain is just gonna stamp on the brake if something pulls out in front of her - ABS will be her best chance at not crashing. Nice video Jason! :)

[@MarkRose1337]

Precisely.

[@rkan2]

I don't think anyone can beat ABS in that situation.

[@racvets1]

ABS was never mandated in the US because of the reasons he stated on gravel/mud. But in 2012, ESC became mandatory in the US, which is based off of ABS and TC, so every vehicle has it indirectly now.

[@aritakalo8011]

Plus it gives the confidence to stomp the brakes. Since the other thing that often happened before ABS was people not applying maximum available brake going long and colliding. Since they knew tires locking up and losing control was a thing and they feared that. So they under braked on not trusting being able to maintain control. So they rather under braked and maintained control, rather than over brake and lose control. It was even part of driver training. Beware of locking up and so on. Modulate braking. Well with ABS installed one can be told.... Just slam that pedal as much as you can. ABS and traction control make sure you don't lock up and lose control.

[@ldnwholesale8552]

Nanny laws for nanny people. Next it will be electric vehicles,, and that is coming. Commonsense and precticality,,,, naah be a sheep!!

[@roymoorman5990]

Great explanation. Looking forward to an episode about electronic stability systems. And then specifically the interaction with ABS. When I did a few simulations of emergency braking while avoiding an object on a wet skidpad I still had to release the brake when the rear stepped out on me to prevent a spin out. When comparing with DSC (bmw e92 m3) off , I didn't really get much stopping distance difference. The instructor said to just slam the brakes, steer around a virtual object while keep braking but it was not possible to keep the car under control like that.

[@benthleydorcin6160]

You have been explaining things exponentially well for years now. Thank you very much, sir.

[@ZMAN24250]

I'm glad you touched on the snow and gravel topic, important to know there are certain scenarios like that. Also glad you touched on the fact that older systems can be not as effective. My old 90s junk is kinda terrible and I feel like it always gets in the way. Never really had the pleasure to experience modern systems though...

[@jongoode3296]

I completely agree about the age. Anything with drum brakes on the back like a 94 S10 or 92 Escort I had were pretty worthless. The 2000 Frontier and 03 Cherokee felt about the same as what I could do myself, so they were probably better, but not noticeably. Our 2013 Leaf and 2011 Pilot aren't just better but they even feel significantly better than anything I could do. Traction control is a separate issue, though and I feel like it's about a decade behind ABS, at least on everyday cars.

[@Varadiio]

I can't say whether newer cars have fixed it, but old 90s cars' ABS is a legitimate hazard today. Over time, rust accumulates between the sensor and wheel hub, pushing the sensor further away. With the increased distance, the sensor has a harder time detecting the wheel speed, and thus assumes total lockup. This means you have no brakes. Always test an older car's brakes at a variety of speeds before relying on them.

[@AlexanderGee]

I think my 2017 Chevy Volt might be one of the few modern vehicles you could plausibly beat. It has two electric motors with regen, three clutches, a gasoline engine, and disk brakes. The hand-off between those systems under braking input is not always predictable and feels very far from optimal. I'd be really interested to know more about how ABS is implemented in systems with friction brakes and regen.

[@pyRoy6]

@@AlexanderGee That would be an interesting test. I would bet a small but not insignificant amount that the engineers were quite thorough, though. The "feel" of many things can be deceptive.

[@nasonguy]

My 2007 focus has trash ABS. Rear only and only in tandem. Definitely *felt* like I could do better than it. However in panic brake scenarios it will still beat me. My 2009 Corolla on the other hand, has 4 wheel individual ABS. 100% can beat me any day. It’s stellar. And that’s from a 14 year old econobox. I can’t imagine what the new hotness is like.

[@taragwendolyn]

Had that conversation with my other half. I try to brake gently (regenerative braking on an EV), and almost never get into ABS. But in the circumstances when I need ABS, I'm glad I have it - it's much better than me. The circumstances where threshold braking enters into the conversation, you're usually thinking about other things such as not steering the car into an obstacle.

[@geemy9675]

I think threshold braking was never really discussed for safety/daily driving, unless you're on ice/snow where ABS performs very poorly. on dry road, it's for for the track and you're no supposed to get anywhere close to lock you brakes on a regular colmute

[@randomvideosn0where]

I'm usually checking the mirror to see if the person behind me is able to stop as quickly. Habit from motorcycle I guess.

[@geemy9675]

@@techno1561 yes in emergency situation in your daily driving abs should perform better because you don't know the exact grip, your tires are most probably not up to optimal temperature, and there's also a high chance that you have slightly different grip on every tire/patch of road, and also that your brake front/rear bias is not perfectly calibrated for the current conditions, so abs will extract the most braking power from each tire. on a track threshold braking makes more sense than on the road because you are doing laps around the same track, you get to test the grip before every corner, the grip is more consistent than on the road, you know exactly were you are going to brake and you can push the limits further and further on every lap, and of course because you are trying to improve your skills in a controlled environment for emergency braking I'd rather rely on abs giving consistent results, than trying to improving the braking distance marginally in the best case, but risking a longer distance because you didn't get it perfectly right. you don't get the chance to do another lap and try again

[@what_to_read]

I have been in the engineering field for a while now and I'm so thankful to be part of this amazing and unique profession. I absolutely LOVE engineering because it challenges me to think outside the box and problem solve in unique ways. It pushes my creativity and innovation while allowing me to use skills I have learned over time to build something that benefits society. I appreciate I Love Engineering for inspiring people to enter the engineering field and for having such comprehensive resources to help engineers grow and succeed. Keep up the incredible work! :)

[@tylermassey5431]

I am always astonished at the difference between your early videos and now. Such an insane improvement in your presentation and delivery. Is it just practice making perfect or did you have a coach/classes.

[@OnE61811301]

I think the most important thing to clear-up is that ABS's main purpose is NOT shorter breaking distance, but not losing steering control while braking. As your number showed, saving a dozen feet of braking distance might make some people say "meh", but your wheels locking in a sharp curve - that's it - game over. Second, the engagement of ABS is almost "binary" - when it activates, it releases the brakes almost completely so that the wheel can start rotating as fast as possible, then it starts braking again with the exact force needed not to overshoot in the slip region again. On measurement it looks like a sawtooth chart. Third, to reiterate your point that it's ridiculous even to think about beating it :D The slip sensors on the wheels even on old ABS systems make several hundred datapoints per second, so before you even think that you should be careful on the brakes, ABS already has calculated the recovery patterns to apply if the threshold is reached. Not only you can't beat it in braking, it already beat you before you even thought about the brakes.

[@androiduberalles]

For some reason I read "game over" in the halo multiplayer announcer voice in my head

[@xapemanx]

sometimes you want your wheels to lock up. with ABS you can't do that. but then again in those scenarios you wouldn't run a setup with ABS to begin with

[@blairleighton3343]

Well, I dunno bout all that but I do know back in the day I could jump on the brakes and the wife would hit her head on the windshield, the kids would hit the back of the seats and everything on the rear window shelf would go flyin past year head. Caint do that with ABS so which is better, you tell me. Dint have seashells neither so There was that. 🍺

[@luizhenriquepaes8991]

@@blairleighton3343 Bro, learn to write, than you can talk about engineering

[@davidjereb]

@@blairleighton3343 Allow me to introduce you to this fabulous newfangled invention, called "the seatbelt". You will be shocked to find that your car might already have them installed.

[@petarpelovski4039]

I 100% agree for new abs systems, but for some 90's system i have found out that any bumps in the road, or patches of road with different grip levels completely freak out the abs taking all brake pressure away from you, to the point where i have been soo close to having an accident in dry weather at shamelessly low speeds. New systems(2010 and up) i have driven do not have this problem tough.

[@compu85]

Some of this might be age / signal degradation. As the tone wheels get rusty the signal gets worse, and then a bump can lead to a false activation.

[@philiptownsend4026]

Brilliant explanatory presentation, 90% I hadn't heard or thought about before. But now I shall. Waiting for another frosty/icy morning so I can play with my ABS and think about what it is doing. And marvel...

[@jerryadams9238]

Thank you for recalibrating my mind. I now understand that 4 channel abs can provide the most braking for each tire. It may be tuned to reduce brake pressure on some tires if you are trying to steer, or it the tail starts to come around. Now I learned threshhold braking in 1968 on a Buick with bias ply tires. These tires made noise so that it was easy to learn. My first car with ABS was a 1992? Ford SHO. This was a 2 channel system, front and rear. If the left tires were on dry pavement and the right tires in sand an slush, then the stopping distances got very long, but with no pull to the side. Next car was a SAAB 900 turbo. It had 3 channel ABS LF, RF, and rear. Stops were very short, but with a lot of steering wheel pull if one side had poor traction. About the year 200? the pulling went away. I assume this was 4 channel ABS. Also, a lot of tires are now quiet at their traction limit. ESP became standard, and then law soon after this. This should couple a steering position sensor with the ABS. Steering while breaking will result in longer stopping distances. I need to practice.

[@Kombivar]

That video makes me appreciate F1 drivers another 150% more than a few minutes before, this is insane and wonderful insight into human vs machine for greater good.

[@matthewazevedo274]

Hubris? In the car/racing community? Inconceivable!

[@Tom--Ace]

It's hubris to discount racing experience with theory alone. In real racing, ABS settings are a complicated topic with no one easy setting for best consistency and speed. Threshold braking can produce faster laptimes, but at the cost of consistency. Higher and lower levels of abs and various abs setups and brake bias and suspension settings also factor into this. So it's not as easy as ABS = always better. If it was, people wouldn't be talking about threshold braking

[@matthewazevedo274]

@@Tom--Ace yeah I know. Thanks for the lecture dad.

[@Tom--Ace]

@@matthewazevedo274 you're welcome son

[@hreb]

Flawless video. I love that Jason addressed different / older types of ABS systems and different road conditions. I still suspect Rally is the one motorsport where ABS would not help even if it were allowed (precisely because of the need to lock up the wheels on gravel). I would like to see a comparison of ABS system types across make / model / year. 4-channel ABS was definitely not the norm when it was first introduced. There are a lot of 1999 Honda Civics out there and not all of us can pick up a Koenigsegg or McLaren like Mr Jason here.

[@ldnwholesale8552]

Rally cars lock wheels because they use a hydraulic seperate handbrake system,, very often way too much.But ABS driving fast on slippery surfaces. Would lose so much time that they may as well stay home

[@adenholmes]

Got my first new car 2 years ago. Went from 98 dodge 2500 w/o ABS to a 21 RAV4 and the safety features it has are crazy. It’s mostly my wife’s car and has been a huge comfort with its terrain management and ABS.

[@davidjereb]

I'd love to see a follow up video of this with some deceleration measurements in a car.

[@LongFacedBastard]

Great video. Jason probably knows this but I want to point out that in racing machines, brake bias adjustments are also made to change how much rotation there is on corner turn-in. Greater rear bias will make the car tend to rotate more. I assume "understeer while braking" would be a great example of a problem with (non-modern/non-racing) ABS although definitely not a problem with all ABS. I'd be super interested in a video on how racing ABS handles things like rotation on turn in, maybe there's a good one out there already.

[@raven4k998]

once abs kicks in that hard enough to push on the brake peddle do not hammer on harder as you can blow the fuse for abs and turn abs off fun fact

[@gupiwa]

"(non-modern/non-racing) ABS" That's really the crux of it. Imagine how good ABS systems would be if they were allowed in F1? These systems are only as good as they need to be and ABS saves lives daily. It doesn't need to be better at rotating my car for that really tight hairpin. It just needs to stop grandma from killing my dog just because she doesn't know how to threshold brake in a panic situation.

[@andymason2]

@@raven4k998 Pedal, punctuation, and no, you can't blow a fuse that way.

[@philippepanayotov9632]

Jason, keep those great videos coming up because they are so good.

[@forcedanonymity1791]

Perfect timing. I was just considering an expensive 6:1 brake lever manual master cylinder. Pretty fancy solution for my need to change from my old ABS system as my motor swap crowded into the old unreliable ABS system. Looks like I need to find a good newer ABS system to integrate into my 95 Integra K swap.

[@Assimilator1]

I thought so anyway, but good to see the details :). 1 possible example of an old car/ABS system that could probably be beaten by a good driver is the optional ABS system fitted to the Ford Escort Mk4 ('86-91), this was a mechanical system, afraid I don't know more than that, but it might interest a few of ya! ;) On a different note there's been a few occasions where I've been damn glad I had it (usually involving animals! And all bar one survived). But there was 1 occasion where ABS caused me to nudge the car in front :p. Car in front of me went onto the roundabout (I followed), then a car pulled out in front of him, he slammed his brakes on, so did I, I was literally just about to stop when the ABS decided it needed to release the brakes! And bump! Minor damage, but it was still annoying! lol (but overall I've been better off with ABS). That incident was in a '96 BMW 323i.

[@josephreisinger33]

Back before ABS, I had a motorcycle accident. It was all I could do to keep the wheels from locking up. 70 percent front brake and 30 rear. At 35 mph I left a 3' skid mark with the rear wheel ( before it came off the ground) and a 9' with the front wheel. The front wheel never fully looked up but unfortunately I still hit the car that was making a left turn in front of me. I had the right of way as per the police.

[@MegaLs2000]

For my next bike, the only rule is it has have ABS. Been on to many scares where you trying to ride the line between not hitting the car and not losing the front

[@Jjengering]

@@MegaLs2000 make sure it has cornering ABS as the bog standard ABS is only really good when you are upright.

[@werdwerdus]

I'm motorcycle riding some times the best way to avoid a collision is swerving out of the way instead of emergency braking. of course it is highly situation dependent. but something to consider

[@dustinroque420]

Too many riders are dependent on abs to save them. Abs doesn't make you stop faster, I don't care what this video says. There are too many variables. Tire choice, brake pad type, brake fluid ratings, even component types ie radial vs transversly mounted systems, master cylinders, rubber vs braided hoses, terrain, temperature of the wheels/surface. A good rider with the right set up and no Abs will stop quicker than an average rider with worn pads, fluid that's never been changed, and tires that are 10 years old. Unfortunately too many riders fall into the latter group and don't maintain their motorcycle, ie replacing tires after 5 years old, brake fluid flush every 6 months, replacing pads or upgrading them to better than stock, or upgrading brake lines.

[@Jjengering]

@@dustinroque420 I get what you are saying and largely agree with the sentiment... But that wasn't my question, I'd like to see a full scientific breakdown of it for motorcycles... As you know it's a complicated matter and so that's why I wanted his breakdown of it. I would say to you though, in the wet upright on the motorway I would absolutely want ABS... there is no way your brain is more superior than the ABS system in this case. We all go ahead and turn off ABS on the track because it's disconcerting banked over knee down with abs kicking in... Well it might just make you lose the front... So I absolutely get that ABS on motorcycles is a more complicated matter... But let's not forget even in MOTOGP, they have very advanced electronics... Turn off all traction control and slide control and the riders will no way be as fast or safe... So unfortunately at some point we need to concede that electronics are superior when tuned properly. I understand the debate is still very hot in the motorcycle community and many riders just hate it, but I want to be open minded and see if there is actually a system that could improve your braking... It seems only logical to me that if we can make all these other systems help us go fast then we can do it on braking too.

[@ethansalgado4391]

My first car was a base model 1998 accord with no traction control or ABS. I was coming over an overpass with a red light on the other end of it kind of fast while it was wet and when I tried to brake it just instantly locked all the wheels every time I tried. Had only seconds to accept that I couldn’t stop and that I was going to crash somewhere. Instead of directly rear ending someone I chose to try to go over the median but ended up oversteering into a palm tree head on. So much so that it hit center more towards the passenger side. Long story short I had a gash on my left leg that just barely missed my knee. I could see the muscles and fat all cut up. And i fractured my right foot needing 2 surgeries. One with pins sticking out of my foot and the second to remove and replace with screws and plates. Thankfully I did not feel any pain because of how much adrenaline was coursing through my veins after the impact. Now I have many scars and a stiff foot over a year later to always remember the day I almost died. Thank god for seatbelts and airbags. And thank god my foot is functional and not deformed. My surgeon told me if I was an athlete this would be career ending so yeah definitely life changing and somewhat limiting. ABS is underrated as F. New cars slow down so quick even when I’m going fast in the rain and I brake hard it just saves my ass every time.

[@nec4608]

Excellent video, I am so glad your approach as an engineer, I am an engineer too, your explanations are always so straightforward and clear. The science always reveals the true. Thanks

[@bsmukler]

It would be interesting to see a similar video regarding modern high-end motorcycles. Generally, the user manuals caution that, in order to achieve the maximum benefit from ABS, the rider needs to wait a beat, that is, rather than panicking and fully compressing the (front) brake lever, you need to smoothly compress it initially, allowing dynamic weight transfer to occur, and then fully engage the brake. On track, you are also taught to do something similar with the throttle upon corner exit: smooth initial (and brief) throttle application followed by pinning it. Of course, all of this becomes much more complicated if you factor in the latest aero and ride height devices used in MotoGP.

[@jessemeyer3052]

I believe the best ABS on off road bikes approaches the performance of an expert in a straight line gravel stop. Which is impressive.

[@SqueakyNeb]

That's not just advice for getting the best from ABS - it's actually the correct advice for getting the best from the tires/brakes themselves (so that ABS can get the best from them). It's not a caution to achieve the best from ABS, it's a caution that ABS is not magic and doesn't make up for completely awful braking technique. Bikes are REALLY susceptible to load transfer, plain ABS can't change that (though I'd bet someone like BMW probably has tech that does...).

[@aarons4205]

The fact that this channel has so many subscribers and is purely educational seems to highlight a flaw in our education systems. Education can be fun and interesting, but often falls short. I would love to get Jason's thoughts on this!

[@joshuabenson2568]

However you shouldn’t forget that part of its popularity might be because the viewer can decide when to watch what topic for however long they choose. In school you are forced to do X for Y hours in a predefined timeframe

[@aarons4205]

@@joshuabenson2568 That's a fair point, but in college you are mostly there by choice and studying a topic of your choosing.

[@pyropulseIXXI]

No engineer is learning anything real from youtube besides supplementary stuff. No doctor, or physicist, or chemist, or biologist, etc. Would you cross a bridge built by a engineer that learned off youtube purely? Would you choose a doctor that learned off YouTUbe? F*CK NO The structure of a university system is vastly superior for learning, as learning at your own pace is extremely slow for most people, because they are lazy. This fact is why they think youtube learning is better; because they can do it whenever they want, and they don't solve any problems, which is where the real learning happens, they just watch. SO no, this doesn't highlight any flaws; this is entertainment and literally takes no effort to do

[@aarons4205]

@@pyropulseIXXI I see you misunderstood my comment. All I'm saying is that learning can be fun and interesting, not that KZbin is a better medium than traditional college. The only thing I'm trying to imply is that maybe education should change to help enforce interest and engagement, something like project based learning could help with (and probably shouldn't be done online). And I completely agree that you have to be very disciplined to learn and retain information in a self-paced online format.

[@joshuabenson2568]

Not KZbin maybe, but KHANUniversity seems to be educational (according to Michael Reeves)

[@ukrdima]

Great video as always. Love the thumbnail even better xD

[@mattacks1655]

Jason, I think you should do a follow up video actually doing some testing on an icy surface. Most conventional ABS systems exaggerate the the grip level and reduce braking too much. The people talking about the Subarus with terrible braking are spot on. Mercedes had a system called Sensotronic Brake Control in the 2000s that did a way better job of getting the wheels as close to that lockup point as possible. If you drove one of those on the same icy surface as a like vehicle with a conventional ABS system, the difference was amazing. It was hard to believe how much grip was possible on an icy surface.

[@Ardyvee]

As a follow up, could we have a small video about the different settings a GT3 car gets for ABS under the series that do allow it? I have the vague idea that it has to do with how aggressive it is, in so far that a series of settings are better for rain than others, and that tire-wear is also affected (ie it changes how much slip the system allows before engaging/how much to reduce pressure), but I don't know details.

[@EngineeringExplained]

Great question - I don't know the setting differences either but a great subject to bring up next time I'm around anything GT3 related!

[@JKDJack]

@@EngineeringExplained Please do a video on GT car Race ABS

[@LatinMasterxx]

@@EngineeringExplained Would be much appreciated! Im 100% on your side, that no human can beat a current ABS. Tho there must be a reason, why modern GT3 cars have like 10..16 different settings for ABS strengt.

[@V8Li]

@@EngineeringExplained You could look into how ABS affects the balance of the car when trail braking aggressively, I only have GT3 experience in simulators however I am always faster with the lowest setting. It might be that in racing there is more to it because they trail brake allot and need to rotate the car at the limit so any unbalance costs time (like flat spots).

[@Insightfill]

Funny enough, when ABS first came out, they found that single vehicle crashes (trees, ditches, etc.) went up compared to non-ABS versions of the same car. Turns out that drivers were "steering into the skid" that never happened, and were just running off the road. Hopefully, now that everyone is used to it, it has gotten better now.

[@LORDH3LPME]

That’s interesting 😂

[@leoshahbazian6830]

I do believe that the reason single vehicle crashes went up was because people relied on ABS to stop their car better, but ABS doesn't increase braking power, it just prevents a loss of control due to wheels locking up. You can still drive too fast for a turn and skid off the road, unrelated to how you brake.

[@malapertfourohfour2112]

The more you swap control of the vehicle from mechanical used input to electronic computer decision-making, the worse drivers en masse will become. Seems awful to me, but w/e 🤷🏿‍♀️

[@Insightfill]

@@malapertfourohfour2112 I had a civil (transportation) engineer once tell me that each person has their own "threshold of safety," and if you raise safety in one area, they'll lower it in others. For example, a driver going from a small car to a big one will "feel safer," and likely drive more aggressively or drop seat belt usage to lower the safety again. It probably comes up in other areas.

[@joelambert7128]

@@leoshahbazian6830 the whole point of the video is that ABS does indeed improve stopping distances, not because the maximum potential braking power of the car changes with an ABS system, but instead because the system gets much closer to that potential in almost all conditions.

[@leandrogouvea9726]

Once again, thank you for this excellent explanation!

[@emaglott]

Great and convincing argument. I totally agree with you. I have a 2003 BMW Z4 with incredible abs braking capability that I could never match autocrossing or on the street. My anecdote, I believe falls into the older crappier systems. I was caught unaware when a wet road became glare ice. 2002 vw golf, I believe a continental teves system that was not 4 channel. When I slammed the brake pedal to the floor hoping for some abs I was already pivoted close to 90 degrees from where the car was headed, and I think the abs saw all the wheels at 0mph and just let me lock them all up.

[@OllamhDrab]

A lot of the bad rap for ABS does come from when it was being introduced: it tended to be a pretty blunt instrument mostly made for panic stops but sometimes getting in your way when maneuvering, and definitely getting in the way of any ingrained instincts to hammer the brake pedal quick as possible *in* panic stops. In the 80's I had pretty remarkable reflexes and practice and it was all I could do not to plunge my Plymouth into the back of some yupster in his Audi suddenly leaning on full ABS. This was the morning I blew off a dentist appointment to go get my car off my last ever bias plies. :) Anyway, very early ABS was basically just taking over the 'hammer the pedal' function and it kind of blew, but it actually improved very quickly, and became pretty unobtrusive and helpful, ...especially if they'd put it on like the rear axle of a pickup that'd tend to get light under braking.

[@nasonguy]

The ABS in my work truck, a 2000 astrovan, is so frighteningly bad. God forbid I’m even slightly braking when I go over a pothole or even largeish crack. It WILL engage. Then immediately disengage. Then as weight shifts again it will engage again. Rinse and repeat a few times as weight keeps shifting around in the garbage vehicle and I have legitimately almost rear ended people during what would be otherwise very calm and slow stops. Talking about going from 35 to stopped in like 150 feet. And this little ABS dance it does takes ALL of those 150 feet. It’s honestly scary. My personal vehicle though, a 2009 Corolla, is completely seamless and confidence inspiring.

[@danoberste8146]

In the early days of ABS I heard* about people slamming on the brakes with ABS but being so shocked by the sound and pedal pulsating that they released the brake pedal because they thought something was wrong. *I have no idea if this is true, or one of those myths. 🤷🏽

[@bjkjoseph]

I drove it an obstacle course at high speeds with puddles and a switch to turn off the ABS, trust me the ABS is 1000% better than regular breaking. The trick is with ABS you need to keep your foot on the break and steer through it and it works awesome

[@easylearn9350]

Lovely lecture. Thanks for sharing!

[@rayoflight62]

Great video, as usual. Traditional explanation with a blackboard are always superior!

[@DonTruman]

Great analysis. Had no idea ABS had changed that much over the years. Figured my 1994 pickup truck with ABS was as good, or close to it, as modern ABS. But maybe not...

[@RobertHancock1]

Some of the older systems were pretty bad. GM used the Delco-Moraine ABS VI system on many vehicles in the 90s, which was a 3 channel system with the rear wheels controlled together, and also used a motor/piston setup which was much slower than the more typical pump/solenoid systems. It was basically designed to be cheap and to be able to say they had ABS.

[@kunstderfugue]

My general notion before watching the video is you can't beat ABS because ABS does threshold braking on each individual wheel, whereas manually you have to watch for every wheel, and you have to lift off your braking input when the first, least grippy wheel starts to spin.

[@Dario01]

Indeed abs controls each wheel individually, but, it doesn't threshold brake, it locks and completely let go of the brake many many times in a fraction of the time. That almost "on off" also breaks a bit the suspension load and reduces grip compared to constantly be on limit by threshold braking

[@qwesx]

​@@Dario01 If you had watched the video (or read any literature about it) then you'd know that this is not how it works.

[@Dario01]

@@qwesx i have some experience in racing simulator for example, and you clearly feel the opposite, obviously the abs reacts much faster than an human, but that don't necessarily mean better braking. And in the sim you can program the abs to be "perfect" instead of "realistic" cause that will further get them apart

[@HuffleMusket]

@@Dario01 @4:22 He goes over this topic

[@Kevin-dt9xm]

@@Dario01 did you really just try to "trust me bro" with your experience from VIDEOGAMES?

[@ZOrdZ]

I used to drive a Fiat Punto 55, no driver aids, not even power steering, no electric windows, no temperature gauge, no abs, it had a 1.1 liter engine (55Hp). In the rain, braking on a red light in a stone paved road (common in Portugal) was equivalent to just not press the gas pedal while in gear. Keep doing great explanatory videos. Than'ks for your work...

[@letsgobrandon416]

I just love watching this sort of detailed dive in to myth busting - more please!

[@JoshuaTootell]

I only have one vehicle with ABS, my new Jeep. Kinda wish my motorcycle had it, but I put so few miles on it that the statistical chance of needing it is pretty slim. It's been a while, but I used to practice threshold braking at high speeds (motorcycle). It is an eye opener to try riding at 90 mph, use maximum braking force, and then look back to see how much ground you covered. It is literally what made me change my riding and driving habits on public roads.

[@microcolonel]

Thanks, I keep telling people this. One of my side projects is a machine learning approach to ABS control (with a failsafe, obviously); in simulation I'm getting a pretty big advantage on challenging terrain, excited to try it on my car.

[@PinkFZeppelin]

What were your results? What are the features? Can’t imagine how machine learning is better than a control loop in this context.

[@rotorblade9508]

very useful stuff only one thing. with racecars you can have adjustable brake bias (even depending on corner phase) and adjustable abs(amout of slip I assume). But the bias helps you to turn in if it’s setup more to the rear. for hard braking you want more towards the front gt cars use abs, tc, automatic gb(sequential pneumatic paddle shift), they seem to be interested in making the cars as fast ast possible, it’s still just as hard to beat a good driver.

[@TheGourmetSnapper]

Jason is the engineering teacher we never knew we needed.

[@donkyuhbuhts540]

An F1 car with ABS would be truly psychotic. The speeds and lap times achieved would be so incredible.

[@youraveragegamer8832]

They actually can't use abs apparently. They tried, but the wheels would get flat spots on them because of how fast they are going

[@oblied]

@@youraveragegamer8832 thats probably why abs has never been introduced into f1 even with tcs and stability control systems being in the cars at certain points

[@ryanmooney5758]

Additionally, one of the reasons F1 drivers frequently lock up coming into the pits is because there's no need to preserve tire integrity and prevent flat-spotting if there will be a new set on the car within 30 seconds. As always, great video. I love the way you're able to visualize and explain mathematical principles. Wish I'd had a math teacher like you.

[@Zyphera]

Your lessons are outstanding.

[@FoxyWoxy-pc8jj]

Very valuable video, thank you for informing us

[@AabhasLall]

Great video as usual. It is amazing that people think that they can modulate the brake pressure 100 times or more per second when they are facing an actively dangerous situation. But this does also remind me of an old joke I used to make. I claimed that my MTB had ABS, and when asked how, I replied "when the tires lock up, I let go of the brakes" 10 years later there are ABS systems for MTBs. I'm not sure if I want that on a bike (I'd like to try them first before judging), but for cars, it is a no brainer.

[@MarkRose1337]

In the mid 2000s, I had ABS activate on me driving a delivery van on the highway. I was unaware there was ice under the bit of snow I was driving on, and prior to then I was unaware the vehicle had ABS. It was locking up the rear wheels too much, causing them to slide, so I reverted to threshold braking to keep directional control. It was a great way to know where the threshold was though.

[@kristianhermann5971]

Really appreciated the explanation of gravel/snow where ABS is not as good - I've wondered this and it's so clear now

[@knill1494]

Hey Jason! Can you please do an in depth video on inline 8 cylinder engines, their firing order, and balances please? There isn't much info out there about it. I know Buick, Dodge, and Alfa all made examples, but I was curious compared to an online six cylinder how the primary and secondary balances match up and if there is any really benefit to the style of engine, obviously they're massive and may be inherently weak at the center point. Anyway, I look forward to the video, if you have already done it, please send me the link. You rock Jason, thanks for helping me become and stay both an auto and engineering enthusiast.

[@joelongjr.5114]

12 years ago I worked for a truck air brake manufacturer after working there for 25 years. I was involved with production of big truck anti-lock air brake valves. ABS is superior to manual braking. Jason is correct. On big trucks short stopping distance is secondary, vehicle stability is primary. It is meant to keep a trailer from jackknifing over the fifth wheel hitch. I believe the range centered for that manufacturer was about 8% slip. Over the road truck trailers modulate either axle by axle or side by side. All the data told there was better performance with more wheel speed sensors. The reason why I don't work there anymore is the manufacturing plant was closed and all equipment was sent to a new facility in Mexico.

[@SI0AX]

Ah, the good ole "outsourcing"!

[@RonJohn63]

@@SI0AX customers always hate seeing price increases.

[@SI0AX]

@@RonJohn63 Price increases are inevitable thanks to the inflation scam. The company I work for is outsouring to dominican republic but now they want to fire them all and outsource to mexicans because their get paid less. Eventually they are going to use robots for the job and not bother pay for employees at all.

[@RonJohn63]

@@SI0AX prices rise because people like -- *or need* -- getting raises (even when their productivity does not increase).

[@SI0AX]

@@RonJohn63 If employees don't get a raise, they actually make less money due to inflation. Do you see supermarkets keep their price the same when inflation rises? No, but they sure do keep the employee wages the same, effectively paying the employees less. That is why the pandemic was such a boost for supermarkets because they indirectly lowered their employees wages.

[@leepower2717]

My first ABS equipped mid 90s built car had an older Bosch 2E system fitted & was lethal in the snow, I used to unplug a wheel speed sensor to disable it so the vehicle would actually stop. Next vehicle early 2000s had a Teves mk60 system & that newer ABS system worked perfectly fine on snow, it also had emergency brake assist that when triggered pulled the car up a lot quicker then you where expecting. FYI I have also found ABS systems work going backwards 😉

[@chandamusonda6883]

Great video 🙌🏾. Would you do an explanation video and demonstration on the importance of ESP or ESC.

[@jonathanmalmut2412]

Jason coming out of the gates swinging on this one. I love it! I feel like he had 10 years worth of arguments about this that he built up and laid it all out here in this video

[@LeatherCladVegan]

The thing that is most difficult about threshold braking is that your weight shifts according to your braking input, which means that the relative pressure applied by you needs to change. So you need to change your braking relative to your change in braking, and that 'double feedback' system makes it very difficult. Maybe my driving position and seat are just terrible, who knows.

[@Keldor314]

It's worse than that, though. Each wheel will have a different weight on it, and so the optimal brake force will be different from wheel to wheel, and there's no way you can optimally redistribute brake force between 4 wheels with only one pedal. Nor can you get around it by tuning brake balance statically. If you're on dry asphalt, you can brake harder, so the car weight shifts more onto the front wheels, meaning they need to have more brake pressure than the back. Now, if you're on ice, you can't slow down as fast, which means that the weight doesn't shift as much, and now your brakes that were perfectly balanced on dry asphalt are locking the front tires and underbreaking on the rear. Modern ABS can get around this by cheating and adjusting the brake force on each wheel independently in response to the car's motion.

[@ant848]

For my taste, threshold breaking is much more controllable in icy/snowy conditions, it's much more intuitive in terms of mass distribution control, especially in a LFB scenario. Probably, none of my cars weren't equipped with a proper ABS system, I don't know, but in most cases I use it only when I need to check how slippery the road is.

[@eatmyfishy]

what vehicle do you have? I have tested this in quite a fee scenarios on my 2017 honda ridgeline and it very much feels like getting into the ABS and then backing off a little is the safest choice…in the packed snow situation of course

[@ant848]

@@eatmyfishy I've tested this approach with two modern 4wd suzukis and an old ff corolla, all MT, so I use engine breaking a lot as well. We have 6 months of winter here so it's quite crucial to have an idea of what's going while driving :) And of course, the only way to find the sweet spot is to trigger ABS for a moment - just as Jason mentioned in this video.

[@7236399]

Jason! As I am close to finish my degree on mechanical engineering, I recently began working dimensioning braking and suspension systems for electrical buses in Chile. So, i stumbled upon documentation on WABCO ABS (and esc) systems. Many, many iterations have come by. It is really interesting, as pneumatic systems are really different from hydraulic braking systems due to compressibility (and friction losses due to sheer size of the vehicles). WABCO has literature on this available, free to the public. So, on this very topic of threshold braking, there are also many disbelievers on buses and truck abs systems, claiming that only humans can do better. It would be very interesting if a part 2 video would come out, focusing on compressed air abs systems.

[@KorkwiN7]

Love these videos. You're awesome dude.

[@stuntmonkey00]

I drove without ABS for two decades. I gotta tell ya, if you need to threshold brake in an emergency, your reaction time to release the locked brake is at least .5 to 1 seconds, a lot of time goes by. When AI finally switched to ABS it was like driving on God Mode.

[@mike325ci]

I think the "pull the ABS fuse when racing" thing I grew up with was just historically because we had older 1990s ABS systems that were not that great. So that's probably the origin of this notion that a human is better than ABS. Since then, in my 80s/90s cars, I don't use the ABS (also because they are broken anyways). But in the 2000s+ cars, I let the modern ABS do its thing, even on the track.

[@ssanc6]

07 Yaris has no ABS, luckily I know to let go of the brakes if I lock up

[@bryankirk3567]

You're right bud. Cool down. Another brilliant and informative show. Thank You.

[@mockingbird9429]

At the track recently overcooked a corner, spun around backwards at 85 mph, clutch and brake to the floor. Looked in the review to see where I was headed then back front and saw two beautiful rows of perfectly spaced dashed tire skid lines. Until then had never thought about the ABS working while travelling backwards.

[@CanopyFlyer150]

Yeah, I gave up that argument many years ago. Early ABS was terrible and I could out perform it, but that was over 30 years ago. Even my current 2014 Camry LE's ABS is multiple orders of magnitude better than I was when I was at my best (doing autocross, or Pro Solo every weekend). Now, in my early 50's, I am not at my best. With that said, I do have a 15 year old currently learning to drive and I am teaching him how to threshold brake, just in case he's ever in a car without ABS, or the ABS has failed.

[@aspecreviews]

Modern Toyotas (after about 2006-2008) have something called vehicle dynamics integrated management, which cooperates pretty much all the control systems into one, and allows them to anticipate a skid (likely using knowledge of optimum wheel slip angles) instead of simply reacting once it starts.

[@berto1014]

@@aspecreviews Pretty much all modern vehicles have a similar system with different names depending on the manufacturer. For example, Stabilitrak for GM, and chassis control in Nissan. All of these systems monitor the steering angle, accelerometer data, and wheel speeds (using the ABS sensors) to accomplish vehicle stability. These systems will limit engine power if the system detects too much acceleration for the steering angle, or apply individual brakes if under/over steering, etc.

[@aspecreviews]

@@berto1014 VDIM can ANTICIPATE a skid, the vast majority of stability systems only REACT once a significant skid is determined to be occurring.

[@berto1014]

@@aspecreviews That's not true. Most systems won't even let you get into a situation where slip occurs because they are actively preventing those conditions. I'm not sure what you mean it can "anticipate" a skid. How could it do that without data indicating slip is occurring or about to like any other system. I have yet to see any information claiming Toyota has a superior system because it anticipates instead of reacts.

[@ThePulse650]

Jason could you do a video explaining why big brake kits are a thing when stock brakes can lock up the wheels? and do big brake kits still improve braking distance? I understand the heat dissipation aspect of larger brakes, but I don't quite understand how they can improve stopping distance, other than maybe offering more fine control over brake force? Also, I have been trying to understand tire contact patch and haven't had much success finding answers. You hear in physics that frictional force is not surface area dependent, so wider tires shouldn't provide more grip, yet performance cars have wider tires, obviously. Is this because of the way the tire deforms and reacts rather than the frictional force alone? Just some things that I haven't been able to figure out thoroughly that are driving me nuts

[@nettles89]

Re: big brake kits, half of the reason is heat dissipation in track settings where you’re using them a lot more and a lot more heavily. The other half is about showing off your big brake kit.

[@jeffduncan9140]

@@nettles89 yep, big brakes are better at heat dissipation. And in normal (non-racing) use, may not heat up enough to be as useful as they could be.

[@zecc81]

They can maintain consistent brake performance for longer in the face of heat, that is their singular purpose. You also typically get better hardware, fixed caliper versus floating for example, but this is not a function of size more cost and use case. As far as your question on tire width, you are thinking more critically about this topic than most people do. Wider tire is more grip right, duh? Well theoretically no, the grip is only a function of the normal force (load) and the coefficient of friction, and both of these are assumed to be constants. A narrower tire has more pressure at the contact versus a wider tire and it all equals out. The full answer to this is actually quite complex and I am probably not aware of everything involved, but it's a few main reasons: The coefficient of friction vs load is actually not perfectly linear, as the load increases the coefficient of friction does increase but with diminishing returns. If a tire is too narrow for the weight of the car you can have excessive contact pressure and will have less grip than an equivalent compound wider tire (why? well now that's a question for a tire engineer and physics of rubber). The other reason is simply that more tire mass can absorb more heat and stabilize the temperature of the tire and there is simply more rubber to wear. You would rapidly overheat and wear down a narrow tire vs equivalent wider tire in a performance driving situation. For these reasons more grip manifests itself as a wider tire but not directly because of its width.

[@christopherjohnston6343]

Tyres are complicated. It's all complicated really. But tyre compound is going to have a way bigger effect than tyre width. As others have said heat management is important. There's also the issue - particularly with track or race compounds where tyres are designed to operate in a certain temperature range so really big tyres can be quite difficult to get hot enough to operate correctly. If you're looking to modify a street vehicle you don't really need to go wider. Just go for a more aggressive compound. Going wider won't necessarily give you much more grip. It will also tramline more and often perform worse in standing water. You also tend to pay more. On that note best way to decrease stopping distances is also tyre selection

[@unclebullfrog7319]

Interesting point about braking on gravel. It is a known fact that a rally car slows quicker when sliding sideways into a corner. In the days before four wheel drive, most of us rallied rear wheel drive, which is a lot of fun. We generally had our brake bias to the rear which, when approaching a corner, a short pump of the brake peddle at turn in would help the rear of the car to step out. Drift cars do some thing similar but mostly with the hand brake. We would would also use that trick for acute corners. Tarmac rallying was quite different; more bias to the front and the brakes would get a real hiding!

[@FernandoFuvio]

Awesome content as always, Jason! Mate, can you explain about tyre blistering and graining?

[@margauxj-broussel9186]

Love it. Since I was explained how ABS works, I was never able to comprehend how the wheels sensors can differentiate between wheel lock up and final rest (velocity = 0). I can understand on modern system paired with ESP using accelerometer and gyroscope. However, on legacy systems relying solely on the wheels speed sensors (often hall effect sensors), I can’t get it. My theory was that there is a preset maximum deceleration timer (under optimal grip and tires conditions) for any given speed. Therefore if wheels appear stopped prior to that timer, brakes pressure is lowered until wheels rotate again. If that make sense. Does anyone know the answer? This have been bothering me for so long.

[@gaborb]

basically your idea can work. Actually it has a "model" reference speed and it knows that there is certain limits within the speed can change. Also if you have ABS it is very unlikely to suddenly have all four wheels at zero speed (as in a real standstill)

[@brent4adv]

Most vehicles also have vehicle speed sensors in the transmission. The car can look at all of the values to determine what's happening (assuming it was programmed correctly).

[@gaborb]

@@brent4adv the transmission sensor don't give you additional information. The transmission in most cases have a fixed connection to the driven wheels.

[@chrissavage5966]

No doubt the early ABS systems were not as good. Many(!) year ago I went on a corporate jolly hosted by Lancia. They had a couple of tame rally drivers (one being Pentti Airikkala, sadly deceased) and a few cars to play with, Integrale Evo and a Thema Turbo. One of the sections was braking. The Thema was rigged with an off-switch for the ABS and we did a couple of runs from maybe 40mph or so (long time ago...). Hit the brakes, measure stopping distance. First was with ABS active, second was with ABS defeated, foot mashed to floor and handbrake (emergency brake) pulled hard on (to defeat the automatic bias compensator) . With 4 locked wheels it did indeed stop shorter than with the ABS, by a decent margin too, although, of course, zero steering control.

[@tuckerantell8449]

That was amazing, informative and hilarious at the same time. Bravo and thanks

[@intron9]

Some people really think that ABS is preventing them to stop earlier at an emergency stop because in that situation you are supposed to make them slip, sacrificing the tire health, to gain some seconds. Thanks for speaking with facts.

[@johnsawatzky9380]

I think part of the distrust of ABS comes from those of us that lived through the early years of ABS. My first experience with it was in my '94 cavalier with front disc brakes and drums in the rear. The drums on the rear wheels were notorious for locking up in certain conditions, especially after sitting a couple of days. The early ABS modules would cycle quite slowly, probably only a handful of times a second, and would cycle all 4 wheels at the same time which would give you a very jerky lurching stop. This caused me several close calls when coming to a stop on snow or loose gravel on pavement and one of the rear wheels would lose traction. A normal slow down turned into the car thinking I was on sheer ice and pumping the brakes as such. The last straw came when the module started failing and would activate under normal stopping and drop the brake pedal all the way down. I deactivated it altogether after that. The newer systems are much better, and do a great job but a little distrust still lingers in the back of my mind.

[@visekual6248]

All that has been said is perfectly valid for traffic application, but from my own experience I can say that on the track not using disabling ABS makes you faster, by increasing your sensitivity and technique, when I disabled ABS first my time increased drastically, but after about 50 laps I managed to catch up to my previous time and currently my lap time dropped by 0.5s, my technique has improved, using things like trail braking and slip angle, and there is still room for improvement.

[@alanh2820]

Once you improved, did you try turning abs back on? Maybe you’re even faster with your new skills and abs combined

[@Granchango]

Most of the guys I know who talk about outperforming ABS have never even driven a parade lap around a racetrack.

[@alanh2820]

They really shouldn’t be talking then lol. I’m curious what the real racers actually experience.

[@visekual6248]

@@alanh2820 No, because it would be useless, maybe if I drove a front wheel drive car, but in a rear wheel drive car you want to brake as lightly as possible, if you brake hard enough for the ABS to kick in, you lose time and may even spin, as weight is transferred from the rear wheels to the front, resulting in loss of traction, and that was my biggest learning, an RWD car you make the turn using the accelerator pedal. That's why FWD cars are easier to drive, the harder you brake the more traction and control you have.

[@alanh2820]

Gotcha so in a race setting, rwd, for the tracks you race on, abs isn’t useful because it’s never even needed

[@oldgeezerproductions]

Recently I was crossing an intersection at a moderate rate of speed. Out of nowhere another car came bombing through to my left illegally and unexpectedly. I instinctively hit the brakes hard as I continued to approach the intersection. Based on my experiences with emergency braking (which I thought I was pretty good at), I just KNEW that I wasn't going to make it and I'd hit the side of the car before I could stop. To my amazement, my Subaru's anti-lock brakes stopped me before I hit and the other car whizzed by unscratched with at least an inch to spare. When I bought my new motorcycle earlier this year, it HAD to have ABS. You are correct about ABS and gravel as I was able to demonstrate for myself a few days ago, however I rarely ride my bike on gravel and take extra caution with speed and braking when doing so. I really enjoyed learning the background why I've had such good experiences with ABS, so thanks.

[@recordedanemone6399]

Thanks for the motivation

[@vnorvi]

I appreciate it is very hard to figure this out. Getting the data for these videos is very difficult. Good job. I am taking racing classes from Porsche and they definitely teach you to stay off the abs. They teach you to use abs as the limit you should not go over, as you suggest- bring it right up to the abs then back off. They have braking sessions in every class. I’ll bring this up, and try it next class. (Yes I’m also an engineer and a geek!)

[@psychosis7325]

As a mechanic and tyre tech with well more test drives than I can count I'd say a really good driver could beat ABS up to about 1998 in Australia and TC/Stability up to about 2004 especially if the cars a bit old and flogged out and no longer on its factory fitment of tyre. After that though 😅 not a chance. I tried and tried and tried and tried 😒 in the end I had to eat my hat and ask Mr Bosch if we could be mates and show me how its supposed to be done 😔 turns out he corners even better than he brakes 😑 I'm not giving up yet though 😅 I want 4x brake controllers wired to my brain before I totally give over to the bots 😆👌

[@theAessaya]

When I was doing my (optional, but I highly recommend) advanced driving on slippery surfaces class a few years back, my instructor went "Remember all that talk about managing your braking and not letting your wheels lock up? Yeah. Forget everything you heard. Unless you're driving a 30 y/o beater w/o ABS, just slam the ducking brake as hard as you humanly can and let the ABS do the work. It'll be better than anything you can do, especially when in panic mode." And then he went on in to explain in detail how modern ABS and ESC systems work, very much in the way you do in this video, just with 100% less whiteboard. And man you can _feel_ the ABS do its work when doing the moose avoidance maneuver on a near-ice like surface.

[@AlexanderBukh]

Excellent presentation!