Nice video, but deserves much more time for such a complex a wide topic. Piston size is one thing, but you can talk about a bunch of other factors: -caliper construction (steel vs aluminum) -caliper type - monobloc or 2-pc Perhaps one more thing... on most modern cars even slightly geared towards performance, the oem caliper is usually very well designed and does not need to be replaced to improve braking. Using better brake pads and/or rotors is what makes most of the difference. The caliper itself will sustain white hot temp before failing, the pads will fade at 1600F even for race compound, way before that for street compound.
I learn so much listening to your various videos on different car related engineering topics. Yes I'm an old codger, but I will readily admit that I know very little about the mechanicals of modern cars, and their technologies and features. Keep up the great work, I look forward to your videos everyday, you seem to be able to break a subject down so the average joe (me) understands your topic. Thanks again for your vids. Regards..
Mark Law Happy to hear it! Cars are a subject of endless complexity, and they combine nearly every form of engineering. In the big scheme of things, I know very little as well. Sharing what I learn as I go. :)
I just upgraded my rear DC2 calipers to a DC5 R caliper setup. Fronts are Spoon monoblocks. Took ABS off ages ago. Car weighs about 1000 kgs. Thanks for continually uploading informative vids!
Thank you for making this video! So many idiots out there claiming a BBK will save you from lockup. The only thing a BBK can do is reduce fade. Most stock setup's do a great job on the street. So many people who think a BBK is the most important upgrade without realizing lines and brake pad compound make a difference to braking performance.
vidurc Big brake kits will increase the likelihood of lockup. If your car goes super fast, this might be necessary to increase brake torque, but for street cars it's quite unlikely you'll need further assistance (hence why ABS exists). Pads can certainly make a huge difference; I'll have content on pads and lines soon.
Another reason for staggered piston sizes is that it gives the pedal a bit more feel as the brake kits get bigger. If you have identical pistons, you are either pressing the whole pad against the disc or you aren't. With a staggered set-up, the larger piston has more effect and you get to apply the brake more progressively, helping to prevent lock-up. However, a downside is that the pads tend to wear at the end with the biggest piston more quickly, and you may have to replace the pad even if it still has some brake material left at the end of the smallest piston.
Hey man, not sure if you remember me, but we met at the BMW event last week. Nice explanation! I am a chemical engineer but I had no idea how the different types of breaks would improve breaking. I loved the videos. Keep posting them!
I always watch your videos looking for information for my own builds , usually your explanations are enough to clear any doubts (or to guide in a direction of thinking). I have a braking "issue" where i could use some consideration. I have a car that has single piston front brakes, it is a heavy car (mazda 929 1994, 1900kg) and has less-than-ideal braking capability. I live in Brazil, all the brands and performance parts that are affordable in the US (with a little financial planning) are barely-existant here and cost usually 5 times more than they would cost you. Upon trying to improve the braking performance of my car (but aiming to source an OEM solution, since it would be more affordable), i started to compare rotor size with other heavy cars that (at lest, for my standards, based on running experience , weight simmilarity and breaking feel) have better braking performance. I found out that the Hilux SW4 (2009-2012 models) have the same rotor size and thickness and use (factory) 4 piston brake calipers up front (and weight more, and break better). Upon simple inspection the piston area seems to be bigger than the 929 braking pot area (measuring everything and adding the 4 pots vs the single pot) and the vacuum assist is roughly the same dimensions (i believe it would matter, the master cylinder has also the same dimensions). Based on your experience and tech savvy, would you think that the Hilux 4pot fron brake system is a upgrage worthy of consideration, or it will end in a case of "trading six for half-a-dozen"? Eager to hear your consideration, thank you for your attention.
Can you make an episode explaining the mechanics on how breaks work? Like what happens when you push the break pedal down and how it applies pressure to the pistons and what not. Also what exactly does the ABS control?
it seems you something missed, the difference in caliper piston size in caliper with more pistons is because discs pads have selfbraking effect and it is the highest on aft part of pads(place where disc enters into pad), that is because on that location is the smallest piston. if all pistons would be same size, it would be uneaven wear( pressure on disc) on pads
Engineering Explained Correction: With staggered pistons, the trailing one is bigger to compensate for the leading edge being pressed agains the disc by the rotational friction.
I know this is an old video and unlikely to get a response, but I’ve got a question you may be able to help with: If the brakes are able to lock up, is that the maximum amount of braking force that can be applied to the car in that instance? Or is it also the caliper design that allows the brakes to lock sooner? In other words: Is there any benefit to swapping a single piston, sliding caliper with a multi piston caliper of the same size/pressure? Does the even spread of pressure in a multi piston caliper allow more force to be applied before lock up occurs? I feel like sliding caliper brakes must have some inherent unevenness in pressure distribution on the pads and may allow the pad to twist slightly within the carrier due to the friction from the discs rotation, onto the disc, and cause lockup sooner? This is all completely unfounded as you can tell, but just a thought I’ve been wondering about and would love to know more lol. Many thanks!
lockup is when pad to rotor friction is greater than tire to road friction. anti lock brakes simply apply less force at this point to keep the brakes from locking up and the car sliding
Did not touch on 'squat' and 'dive'. While making little difference to a suburban run about, in higher performance cars, designers take into account the reaction force from the brake rotor through the caliper into the suspension. So the caliper at the rear of the front wheel will try to lift the front to counteract dive and the caliper at the rear axle is toward the front so the reactive force tries to pull the rear of the car downward. This reduces longditudinal pitching and also the polar moment of rotation under heavy braking and enables the car to have more stability under heavy braking.
Bruh. This guy is just amazing. So let me get this straight, from what I once in my life learned, brembos are better brakes and are on performance cars because they have multiple pistons in their calipers? Or is it because Brembo makes bigger calipers, brake pads, and rotors on the car? I just wanna know why Brembos come on performance cars is all.
there has been a lot of debate as to which honda civic chassis is best (performance wise) and why, as well as the advantages and limitations of each generation as a performance platform... i could think of nobody on youtube more qualified to do it than you. please consider it!!!
Could I ask you a smoking brake pad question? Assume a normally healthy and maintained brake system... when brakes are worked hard what is actually smoking? I drive a 2006 Ram 2500 4x4 5.9 I-6 Cummins with 340k miles. I do the maintenance myself (former F/A-18 avionics tech). On a recent tow at trailer capacity (8k lbs) through the hills of N. GA I arrived home to find rear brakes smoking. There is a proportioning valve that sends more breaking power to the rear when heavy loads are present. This trip is certainly the hardest I've ever worked the rear brakes. Was smoke likely coming from materials in the pads, dirt on rotors, rotors, or something else? Thanks for your insight! a Google search wants to tell me why they are smoking. I know why but, not what.
i wondering how the stopping force is relating to the speed of the disk, for example at 30mph the force needed to lock the wheel is 100lbs of force applied by the piston(s) on the pad. at 60mph what it would be? i don't think is proportional or is it? Engineering Explained
Daniele Dal Col Kinetic energy is 1/2mV^2, V being velocity, so the amount of energy required to stop a vehicle moving at 60 mph is 4 times greater than a car moving at 30 mph (rather than two, the relationship is squared not linear).
Engineering Explained Yes, energy required for getting the car to a complete stop is 4 times higher, when vehicle travels with twice the speed. But the force / pressure one has to apply in order to lock up the wheel is (ideally) constant over speed, or am I completly lost here? So basically if the wheels begin to lock up with 100lbs of brakeforce applied at 30 mph, they will start to lock up at 60 mph at 100lbs as well!? I posted a similar question... would like to read your opinion. ;-)
Sebbl1990 Short answer is no, they will not lock up at 60mph. EE explained it, there will be 4x the kinetic energy in the rotating assembly and will then require more clamping force (ballpark 4x, though not exactly) to reduce the energy enough to lock it up.
I heard that larger disc size alone will not help you brake in the real world. The guy said something like "surface area is not a coefficient of friction". Something along the lines of a trapezoid shaped box. Its no easier to push long the floor with the big side down than the small side. This was almost 15 years ago in college and not in a math or science class. It was in film school. He said if I wanted to stop better on my motorcycle, a larger rotor wouldn't help. I had a single rotor on the front wheel. I wanted to change wheels with a bike that came with twin rotors up front or find one that was bigger aftermarket. He said a better caliper and cylinder would do that but more rotors or larger rotors only divides up the finite force you already have. (bikes, so obviously no vacuum assist. IDK if that matters). Was he wrong or right or somewhere in the middle? I've been thinking about this for 15 years. Put this to rest for me, will you?
The smaller piston in the staggered piston caliper would have more pressure because there hydraulic pressure would be the same and the piston being smaller would be exert more force relative to size and pressure applied.
+Pete Prisyazhnyuk Well I said hydraulic pressure would be the same. Think of a pencil point and a pencil eraser. press the pencil point on your skin with some sort of force it hurts right? but press the eraser on your skin using the exact same force, doesnt hurt right? That's because the smaller something is using the same pressure and force as something that is bigger, the smaller will exert more pressure than something that is bigger in size. That's why tanks use wide long tracks because it exerts less pressure.
+Engineering Explained: If you change your calipers for one with more or bigger pistons, are there any considerations for how the ABS of the vehicle is tuned for the stock calipers?
Just wanted to mention that the part where you say "As it gets heated you need more pressure" seemed a little hand wavy. Everything else seemed to me very well explained, including the part where the debris builds up towards the rear of the brake pad. But this particular sentence where you mention heat didn't have much in way of an explanation, which I feel seems warranted. Excellent video otherwise, as always! Keep it up!
CptAJbanned As the rotor heats, typically the coefficient of friction will drop between it and the pad. In order to maintain the same brake force, you'll need more pressure to compensate.
I change 240mm solid to 260mm vent, the weight of caliper and disc are double the old one (240mm). Now to car understeer more, and wheel steering slightly more heavier. Can you explain gyroscope effect of heavier brakes? Only found about the wheels.
Question. Are rebuilt brake caliper as good as OEM Subaru calipers for my impreza ? The one I have on has a stuck piston and I ended up warping my right front rotor...
I felt like you rushed through this video -____- which is most/least expensive? which would make more sense to add to a vehicle? Which would give you the best performance or last per buck spent?
Let's say, I'd like my break to bite more, but also to be more enduring (cause after 1 or 2 heavy braking, I'm having a little brake fade and huge brake vibrations). I then need to change the calliper, but what else should I change / improve? I guess it is related to heat dissipation, therefore needing different discs only? What about the break pads, and what about the rightfulness of a BBK?
Here is a good question, what would be better in a closed situation where none of the values change. Would it be better to have two large pistons equaling a total surface area of say 4" for both of the pistons. Would it be better to have that set up, or a 4 piston caliper but the total surface area is 3.5"?
yuki no inu The more even pressure from the 4 pistons might actually get more out of your brake pads. But telling you which one would be better with random values here is pretty difficult, and I don't have the knowledge for that.
Does changing to a different caliper need any changes to the existing master and slave cylinders? I am from India and my car is an automatic and compared to other cars around i need to push on the brake harder than usual for it to stop. Does this mean the vacuum boost i am getting is bad or the calipers are bad. It would be great if you could help me out.
Can you make a video about the ratios for hydraulic brakes when used in an after market pedal box, line locks when used for hydraulic hand brakes systems, proportioning valves, brake boosters (remote boosters and booster-less hence pedal ratio) and the different kind of fluid and lines? There's so much that goes into making a car stop effectively. Obviously tires are the symbiotic relationship here but it starts with the brakes. Also would be good to touch on cars with out ABS. In Rally racing you do not want ABS. Care to explain why?
TheSigp220 It appears what you are asking for is application specific design engineering and certainly cannot be adequately addressed in a generic TH-cam video. My suggestion would be to contact the technical support/engineering department of aftermarket high performance brake systems manufacturers such as Brembo, Wilwood, SSBC, Baer, K-Sport and Hawk and enlist their expertise and help. Most have guides including formulas and calculators available to address some generic and specific application design. I believe EE indicated that there is content coming that addresses brake lines and fluids. Tires are an important component, but also don't neglect suspension, geometry, and dynamic loading. A World Rally Car could at times benefit from ABS, but ABS would be counter productive when wanting to set the vehicle attitude or direction by deliberately breaking traction to induce oversteer or all wheel drift with brake application, especially on corner entry, the same would also hold true for drift cars. Good luck with your quest for knowledge.
So it is generally accepted that the Spoon calipers does not decrease stopping distance; but it helps heat dissipation. After watching your video; it seems that the Spoon calipers should help since it has more cylinders than stock; as well as using different size cylinders from leading to trailing edge. Could you explain a little if those have a measurable impact? Does the fact that the Spoon Calipers use stock size pads, mean that it performs the same as stock calipers? (all the above in reference to an S2K)
I don't understand why wheels would lock up more easily at low speeds compared to high speeds. In my opinion the required braking force should be fairly constant over speed when braking, unless you have a vehicle which has noteable amounts of downforce, which everyday cars don't. That said - top notch videos, really like the short scientific approach! Been watching your videos for quite a while now.
vidurc Well, mass doesn't change when you go faster, does it? At least if you don't consider Einsteins theory of relativity ;-) or changing gear while braking (influence of moment of inertia changes with different gear ratios). But we can put these aside for my question. The maximum of brake pressure applied before the wheels lock (or ABS kicks in) should only depend on the vertical wheel loads and the friction coefficient µ. I don't see why the two should change over speed.
Sebbl1990 No the mass doesn't. You however have mass spinning at a higher rate. So the force acting upon it does. When you hit the brakes it causes friction and heat to increase and essentially the friction between the pad and disc is what causes the braking force. So the faster the wheels are turning the more force is require to get it to stop instantaneously. You have a lot more kinetic energy that needs to be removed from the equation to eliminate all the force. The vertical wheel load and friction coefficient would only be 2 pieces of the puzzle. You are talking about eliminating speed through friction through the use of a stationary component and a moving component coming in contact. The inertia of the moving component still needs to be eliminated in order for it to be stopped completely. With braking force being equal during both applications, the time it takes for friction to build, and braking force to be applied, depends on how quickly said object is moving. This is also the reason why lighter brakes, tires, wheels, and axles can drastically improve braking performance.
Sebbl1990 a brake rotor rotating at higher speeds has more kinetic energy. Not only does the necessary energy for braking increase with speed, it is also not linear. E = m*v^2 this means double the speed requires 4 times as much energy to stop
Sebbl1990 he explained it on an earlier post....." Kinetic energy is 1/2mV^2, V being velocity, so the amount of energy required to stop a vehicle moving at 60 mph is 4 times greater than a car moving at 30 mph (rather than two, the relationship is squared not linear)." just think of it this way, when you have something with mass moving, the faster it goes more force is required it is to stop or slow down. Kind of like how some top fuel drag cars require parachutes to slow down rather than just conventional brakes
So.... Why does high speed braking require more clamping force? Downforce (probably not)? Reduction in pad friction coefficient at high surface speeds/temperatures?
So we learned that area matters. How about decreasing the "hole" on the piston thus increasing the size of the "wall" and then having a larger area that presses onto the brake pad?
MrThejuzam that changes nothing. what you need is a big area for the brake fluid to press against the piston, not for the piston to press against the brake pad. brake fluid pressure x Area of piston = clamping force
MrThejuzam heat dissipation and/or transfer to fluid. I am no engineer but I would assume having a greater surface area would also hold in more heat that would also transfer to the fluid pushing the piston which would affect braking performance overall
You mentioned that most brakes are easy to lock up which is why we have ABS, but doesn't that defeat the object of larger callipers, pads etc. ?? Even with more clamping force onto the disc won't the wheels still lock up at the same 'place' if the car has the same contact point (tyres) and grip levels on the road surface?
can i ask you, where did you learned all that stuff? And btw i watch all your videos and some of them twice or more ;D keep up the great work dude:) Greetings
Dear EE, In the staggered configuration, the last piston at the end of the arched brake is there to compensate for "inefficiencies" of the first smaller pistons, if I understand well due to speed difference. So why dont you have an array of larger pistons straight away, of maybe big piston small piston, big piston small piston?
My workshop installed a AP Racing CP9202 on the front brakes. The piston is smaller compare to Model CP9200. Is this setup of CP9202 ok for front brakes? The reason is for the allowance for a bigger Rotor of 345mm compare to max 330mm on CP9200
Interesting video as always. Have you or would you look into producing a video the effects of brake upgrades in relation to brake bias and locking wheels.
Totally off the subject but I'm struggling to find information. I have a wrx hawkeye 2007. The boot will not release from the handle inside the car ? Also the petrol tether ( the plastic bit holding the petrol cap ) has snapped but I can't get a replacement anywhere in the UK without buying the whole petrol cap too ?!
Would 2 sets of 2 piston calipers for the front brakes of a vehicle be sufficient enough for even brake wear on the pads? Thanks, keep up the good work!
thank you for all your helpful videos I like your explanation methods :) can you help me with this.. :) I intend to convert the rear drums to disc brakes.. I would like to hear your advice :)
How do you decrease the likelihood of actual lockup via added pressure? Other than ABS, more downforce, or better tires, are there any other variables to assist in better stopping power without locking up?
Is there a difference between single sided two pistons vs oppose sided 4 pistons in terms of the clamping force? If each piston is the same diameter? Floating caliper has pistons in single side but it has a moving mount the other side. Would it make the clamping force a double in terms of their size of piston surface?
Question, for a leightweight sportscar (1994 Mazda Miata base) would it be better to have a big brake kit or dual calipers on the rear brakes? This will eventually be a track car but it is my daily driver right now and im interested in tuning it for street applications atm.
Engineering Explained are wheel spacers good for race car or not? and why ?,i have 2010 STI HB and i was planning to get them but i want to know are they good for track or it just give a nice look?
Hi! What do You think - is there a difference between cheap (or just cheaper brake calipers ) vs expensive or top of the line brake calipers? Standard OEM type(style), non performance calipers.
Are there any negative side affects or any advantages to pumping your brakes when coming to a stop these days with the advent of ABS? Thanks. Awesome channel, BTW
I just searched my question and came up with this... According to the experts: You do not have to pump your brakes. In fact, if you pump them while braking hard, you will lose the benefits of the ABS. During emergency hard braking, apply firm pressure to the brake pedal; do not take your foot off the brake until your vehicle comes to a full stop. Essentially, brake and steer. When the ABS is working, you may notice vibrations/pulsations on your brake pedal and a grinding sound. This is normal and signs that the ABS is engaged. www.meldonlaw.com/faqs/do-i-have-to-pump-my-breaks-to-keep-from-skidding-if-i-have-an-abs/
Even race cars can use normal calipers because the performance calipers are quite expensive and can cost at least 6k. But you will see them mostly on luxury large cars just because they are on the list of optionals and the owners simply click a button and add them. But it isn't that it's a bad thing because it's not wrong to have good brakes.
How does braking effectiveness correlate to temperature? We all know that brakes are less effective when really hot, but are they also less effective when really cold? I've noticed several times driving a long distance on the freeway on a really cold night, having not touched the brakes in as much as an hour and presumably the pads and rotors around freezing or so, I get off the freeway and find the brakes aren't very effective, less than I would expect, but when I'm driving in traffic they grab real good. This isn't any sort of performance pads as far as I know, but the setup isn't power-boosted (it's an old VW Bug converted to disc all around).
So that means the larger number of pistons is only needed for very bigger brake pads, otherwise it wouldn't be necessary to have a 8 pistons brake caliper, in relation to the size of one piston
I have a question. regarding breaks. break pads and rotars as a combination what do you feel is the best for high performance racing level driving? I enjoy taking my car to the track as well and also being how I live in South East Asia and many very stupid drivers on the road here. like to be able to have to same braking safety level on the street as I do on the track. but with so much out there and despite all the information I know. I honestly am not sure anymore what is the best way to go
HOW EASY OR HARD WOULD IT BE TO change the rear calipers on 07 ram 1500 from single piston to double piston like they have on the ram 2500. Could I just change the calipers and it be good. the brake line threads and sizes are the same. I have powerstop pads that were bought using the 1500 model. I am getting a travel trailer soon so I'd like to improve brakes here if I can
@@EngineeringExplained Hi bro! I have a serious question:) If I buy a bigger rotor, will it increase the brake performance? For example, if I have a 288mm rotor and I change it to a 321mm rotor, but I don't change the pads because the manufacturer used the same pads for both rotors. I think, it won't increase the brake performance since I didn't change the surface and I also didn't change the pressure of the brake booster. (As I know my booster can produce 3 kiloNewton) Pls make a whiteBoard explanation:D thanx!
hi, i am wondering about the rotor/axle abuse happening when the outside brake pad on the single piston caliper starts to worn and shrink in size. i guess that the caliper on this setup is fixed and not adjusting to keep the outside pad close to the rotor over time. am i right?? what can you tell us about that concern i just brought up?
+Elie Nehme Brake fluid pressure is what allows the front caliper to adjust to the wear of the brake pad. Single piston, sliding rear calipers tend to ratchet out and that ratcheting action combined with brake fluid pressure is what keeps them constantly adjusting to the brake pad wear.
what is the difference in calculation of force on pads when we consider a fixed type caliper having two piston opposite to each other and other having only one piston ?
If I replaced my brake calipers with a bigger pistos, will this affect the abs system? I mean the speed of locking and unlocking due to the larger piston
I heard brembo caliper stickers works wonders too. Only $5 for a set of 4 in any color you want.
bmwmsport11 Investing now.
Engineering Explained which Gopro suction cup mount do you use? And it would be cool if you took cars to the track
Engineering Explained difference in floating calipers vs hard mounted ? pros and cons?
Definitely increases heat dissipation by 50%
Nice video, but deserves much more time for such a complex a wide topic.
Piston size is one thing, but you can talk about a bunch of other factors:
-caliper construction (steel vs aluminum)
-caliper type - monobloc or 2-pc
Perhaps one more thing... on most modern cars even slightly geared towards performance, the oem caliper is usually very well designed and does not need to be replaced to improve braking. Using better brake pads and/or rotors is what makes most of the difference. The caliper itself will sustain white hot temp before failing, the pads will fade at 1600F even for race compound, way before that for street compound.
I learn so much listening to your various videos on different car related engineering topics.
Yes I'm an old codger, but I will readily admit that I know very little about the mechanicals of modern cars, and their technologies and features.
Keep up the great work, I look forward to your videos everyday, you seem to be able to break a subject down so the average joe (me) understands your topic.
Thanks again for your vids. Regards..
Mark Law Happy to hear it! Cars are a subject of endless complexity, and they combine nearly every form of engineering. In the big scheme of things, I know very little as well. Sharing what I learn as I go. :)
I just upgraded my rear DC2 calipers to a DC5 R caliper setup. Fronts are Spoon monoblocks. Took ABS off ages ago. Car weighs about 1000 kgs. Thanks for continually uploading informative vids!
Thank you for making this video! So many idiots out there claiming a BBK will save you from lockup. The only thing a BBK can do is reduce fade. Most stock setup's do a great job on the street. So many people who think a BBK is the most important upgrade without realizing lines and brake pad compound make a difference to braking performance.
vidurc Big brake kits will increase the likelihood of lockup. If your car goes super fast, this might be necessary to increase brake torque, but for street cars it's quite unlikely you'll need further assistance (hence why ABS exists). Pads can certainly make a huge difference; I'll have content on pads and lines soon.
Another reason for staggered piston sizes is that it gives the pedal a bit more feel as the brake kits get bigger. If you have identical pistons, you are either pressing the whole pad against the disc or you aren't. With a staggered set-up, the larger piston has more effect and you get to apply the brake more progressively, helping to prevent lock-up. However, a downside is that the pads tend to wear at the end with the biggest piston more quickly, and you may have to replace the pad even if it still has some brake material left at the end of the smallest piston.
Hey man, not sure if you remember me, but we met at the BMW event last week. Nice explanation! I am a chemical engineer but I had no idea how the different types of breaks would improve breaking. I loved the videos. Keep posting them!
You do not want to improve "breaking" as you want your car to be reliable. You may want to improve the "braking" performance of your car though.
@@schumifan78 LMAO this made me laugh for a minute
Best video from you, because it’s short and to the point👊🏾
Red paint improves braking? I thought it adds +10kw per wheel.
The improvement in braking force is a side effect of the extra 10kw
DrathVader96 Yeah Marty and Moog told us so its basically true :D
DrathVader96 No of course not its 9kw per wheel and free cookies
kilowatts that electricity son we use gas burning horses here not one of thoes electric cars them socialist use
watt is a measure of power kid. horse power/kilowatts. imperial/metric.
I always watch your videos looking for information for my own builds , usually your explanations are enough to clear any doubts (or to guide in a direction of thinking). I have a braking "issue" where i could use some consideration.
I have a car that has single piston front brakes, it is a heavy car (mazda 929 1994, 1900kg) and has less-than-ideal braking capability. I live in Brazil, all the brands and performance parts that are affordable in the US (with a little financial planning) are barely-existant here and cost usually 5 times more than they would cost you.
Upon trying to improve the braking performance of my car (but aiming to source an OEM solution, since it would be more affordable), i started to compare rotor size with other heavy cars that (at lest, for my standards, based on running experience , weight simmilarity and breaking feel) have better braking performance. I found out that the Hilux SW4 (2009-2012 models) have the same rotor size and thickness and use (factory) 4 piston brake calipers up front (and weight more, and break better). Upon simple inspection the piston area seems to be bigger than the 929 braking pot area (measuring everything and adding the 4 pots vs the single pot) and the vacuum assist is roughly the same dimensions (i believe it would matter, the master cylinder has also the same dimensions). Based on your experience and tech savvy, would you think that the Hilux 4pot fron brake system is a upgrage worthy of consideration, or it will end in a case of "trading six for half-a-dozen"?
Eager to hear your consideration, thank you for your attention.
Can you make an episode explaining the mechanics on how breaks work? Like what happens when you push the break pedal down and how it applies pressure to the pistons and what not. Also what exactly does the ABS control?
Never heard of staggered piston calipers, good video.
Tailz99! Do u know where can I buy one ?
it seems you something missed, the difference in caliper piston size in caliper with more pistons is because discs pads have selfbraking effect and it is the highest on aft part of pads(place where disc enters into pad), that is because on that location is the smallest piston.
if all pistons would be same size, it would be uneaven wear( pressure on disc) on pads
Engineering Explained Correction: With staggered pistons, the trailing one is bigger to compensate for the leading edge being pressed agains the disc by the rotational friction.
Baladibt The leading edge is not sucked in, disc brakes are not self energizing like some drums.
I know this is an old video and unlikely to get a response, but I’ve got a question you may be able to help with:
If the brakes are able to lock up, is that the maximum amount of braking force that can be applied to the car in that instance? Or is it also the caliper design that allows the brakes to lock sooner?
In other words:
Is there any benefit to swapping a single piston, sliding caliper with a multi piston caliper of the same size/pressure? Does the even spread of pressure in a multi piston caliper allow more force to be applied before lock up occurs?
I feel like sliding caliper brakes must have some inherent unevenness in pressure distribution on the pads and may allow the pad to twist slightly within the carrier due to the friction from the discs rotation, onto the disc, and cause lockup sooner?
This is all completely unfounded as you can tell, but just a thought I’ve been wondering about and would love to know more lol.
Many thanks!
lockup is when pad to rotor friction is greater than tire to road friction. anti lock brakes simply apply less force at this point to keep the brakes from locking up and the car sliding
Did not touch on 'squat' and 'dive'. While making little difference to a suburban run about, in higher performance cars, designers take into account the reaction force from the brake rotor through the caliper into the suspension. So the caliper at the rear of the front wheel will try to lift the front to counteract dive and the caliper at the rear axle is toward the front so the reactive force tries to pull the rear of the car downward. This reduces longditudinal pitching and also the polar moment of rotation under heavy braking and enables the car to have more stability under heavy braking.
what would be better.. 2 piston caliper with big stock rotor (bigger pad) or 4 piston caliper with small drilled/slotted rotor (smaller pad)?
Bruh. This guy is just amazing. So let me get this straight, from what I once in my life learned, brembos are better brakes and are on performance cars because they have multiple pistons in their calipers? Or is it because Brembo makes bigger calipers, brake pads, and rotors on the car? I just wanna know why Brembos come on performance cars is all.
there has been a lot of debate as to which honda civic chassis is best (performance wise) and why, as well as the advantages and limitations of each generation as a performance platform...
i could think of nobody on youtube more qualified to do it than you. please consider it!!!
Could I ask you a smoking brake pad question? Assume a normally healthy and maintained brake system... when brakes are worked hard what is actually smoking? I drive a 2006 Ram 2500 4x4 5.9 I-6 Cummins with 340k miles. I do the maintenance myself (former F/A-18 avionics tech). On a recent tow at trailer capacity (8k lbs) through the hills of N. GA I arrived home to find rear brakes smoking. There is a proportioning valve that sends more breaking power to the rear when heavy loads are present. This trip is certainly the hardest I've ever worked the rear brakes. Was smoke likely coming from materials in the pads, dirt on rotors, rotors, or something else? Thanks for your insight! a Google search wants to tell me why they are smoking. I know why but, not what.
The title had me laughing out loud haha.
i wondering how the stopping force is relating to the speed of the disk, for example at 30mph the force needed to lock the wheel is 100lbs of force applied by the piston(s) on the pad. at 60mph what it would be? i don't think is proportional or is it? Engineering Explained
Daniele Dal Col Kinetic energy is 1/2mV^2, V being velocity, so the amount of energy required to stop a vehicle moving at 60 mph is 4 times greater than a car moving at 30 mph (rather than two, the relationship is squared not linear).
Engineering Explained Cool thx man!
Engineering Explained Yes, energy required for getting the car to a complete stop is 4 times higher, when vehicle travels with twice the speed.
But the force / pressure one has to apply in order to lock up the wheel is (ideally) constant over speed, or am I completly lost here? So basically if the wheels begin to lock up with 100lbs of brakeforce applied at 30 mph, they will start to lock up at 60 mph at 100lbs as well!?
I posted a similar question... would like to read your opinion. ;-)
Sebbl1990 good one waiting for replies!
Sebbl1990 Short answer is no, they will not lock up at 60mph. EE explained it, there will be 4x the kinetic energy in the rotating assembly and will then require more clamping force (ballpark 4x, though not exactly) to reduce the energy enough to lock it up.
I heard that larger disc size alone will not help you brake in the real world. The guy said something like "surface area is not a coefficient of friction". Something along the lines of a trapezoid shaped box. Its no easier to push long the floor with the big side down than the small side. This was almost 15 years ago in college and not in a math or science class. It was in film school.
He said if I wanted to stop better on my motorcycle, a larger rotor wouldn't help. I had a single rotor on the front wheel. I wanted to change wheels with a bike that came with twin rotors up front or find one that was bigger aftermarket. He said a better caliper and cylinder would do that but more rotors or larger rotors only divides up the finite force you already have. (bikes, so obviously no vacuum assist. IDK if that matters).
Was he wrong or right or somewhere in the middle? I've been thinking about this for 15 years. Put this to rest for me, will you?
The smaller piston in the staggered piston caliper would have more pressure because there hydraulic pressure would be the same and the piston being smaller would be exert more force relative to size and pressure applied.
+Pete Prisyazhnyuk Well I said hydraulic pressure would be the same. Think of a pencil point and a pencil eraser. press the pencil point on your skin with some sort of force it hurts right? but press the eraser on your skin using the exact same force, doesnt hurt right? That's because the smaller something is using the same pressure and force as something that is bigger, the smaller will exert more pressure than something that is bigger in size. That's why tanks use wide long tracks because it exerts less pressure.
the pressure between pad with disc will be even when the smaller piston is in the leading side ，I think this is the main reason
+Engineering Explained: If you change your calipers for one with more or bigger pistons, are there any considerations for how the ABS of the vehicle is tuned for the stock calipers?
You should make a video about what the differences in tunes. Like what's the real difference between a stage 1 and a stage 2 tune??
Ian Jacob It's a marketing term. Whoever creates the "stages" will be able to tell you. It will be different for different companies.
Just wanted to mention that the part where you say "As it gets heated you need more pressure" seemed a little hand wavy. Everything else seemed to me very well explained, including the part where the debris builds up towards the rear of the brake pad. But this particular sentence where you mention heat didn't have much in way of an explanation, which I feel seems warranted.
Excellent video otherwise, as always! Keep it up!
CptAJbanned As the rotor heats, typically the coefficient of friction will drop between it and the pad. In order to maintain the same brake force, you'll need more pressure to compensate.
you should also discuss brake fluid... that makes a huge difference even on normal calipers
I change 240mm solid to 260mm vent, the weight of caliper and disc are double the old one (240mm).
Now to car understeer more, and wheel steering slightly more heavier.
Can you explain gyroscope effect of heavier brakes? Only found about the wheels.
Question. Are rebuilt brake caliper as good as OEM Subaru calipers for my impreza ? The one I have on has a stuck piston and I ended up warping my right front rotor...
I felt like you rushed through this video -____- which is most/least expensive? which would make more sense to add to a vehicle? Which would give you the best performance or last per buck spent?
ElxChino Adding tech adds cost. Story of life. :)
Sometimes i'm pist'n staggering....... Does that make a difference? On a serious note, though. Love the videos.
Gonna try red paint first.
Let's say, I'd like my break to bite more, but also to be more enduring (cause after 1 or 2 heavy braking, I'm having a little brake fade and huge brake vibrations).
I then need to change the calliper, but what else should I change / improve?
I guess it is related to heat dissipation, therefore needing different discs only? What about the break pads, and what about the rightfulness of a BBK?
I was hoping you'd include floating calipers in this video!
Here is a good question, what would be better in a closed situation where none of the values change. Would it be better to have two large pistons equaling a total surface area of say 4" for both of the pistons. Would it be better to have that set up, or a 4 piston caliper but the total surface area is 3.5"?
yuki no inu More pistons = more even pressure on the pad. More area = higher braking force.
yuki no inu The more even pressure from the 4 pistons might actually get more out of your brake pads. But telling you which one would be better with random values here is pretty difficult, and I don't have the knowledge for that.
Does changing to a different caliper need any changes to the existing master and slave cylinders? I am from India and my car is an automatic and compared to other cars around i need to push on the brake harder than usual for it to stop. Does this mean the vacuum boost i am getting is bad or the calipers are bad. It would be great if you could help me out.
Need to explain about the fixed caliper vs. floating caliper
Dear Engineering Explained,
How much HP increase can I expect to get from:
a: a Red Paint job
b: a Racing Stripe
c: a Dual racing stripe
Can you make a video about the ratios for hydraulic brakes when used in an after market pedal box, line locks when used for hydraulic hand brakes systems, proportioning valves, brake boosters (remote boosters and booster-less hence pedal ratio) and the different kind of fluid and lines? There's so much that goes into making a car stop effectively. Obviously tires are the symbiotic relationship here but it starts with the brakes. Also would be good to touch on cars with out ABS. In Rally racing you do not want ABS. Care to explain why?
TheSigp220
It appears what you are asking for is application specific design engineering and certainly cannot be adequately addressed in a generic TH-cam video.
My suggestion would be to contact the technical support/engineering department of aftermarket high performance brake systems manufacturers such as Brembo, Wilwood, SSBC, Baer, K-Sport and Hawk and enlist their expertise and help.
Most have guides including formulas and calculators available to address some generic and specific application design.
I believe EE indicated that there is content coming that addresses brake lines and fluids.
Tires are an important component, but also don't neglect suspension, geometry, and dynamic loading.
A World Rally Car could at times benefit from ABS, but ABS would be counter productive when wanting to set the vehicle attitude or direction by deliberately breaking traction to induce oversteer or all wheel drift with brake application, especially on corner entry, the same would also hold true for drift cars. Good luck with your quest for knowledge.
Awesome. You deserve more subscribers!
So it is generally accepted that the Spoon calipers does not decrease stopping distance; but it helps heat dissipation. After watching your video; it seems that the Spoon calipers should help since it has more cylinders than stock; as well as using different size cylinders from leading to trailing edge. Could you explain a little if those have a measurable impact? Does the fact that the Spoon Calipers use stock size pads, mean that it performs the same as stock calipers? (all the above in reference to an S2K)
I don't understand why wheels would lock up more easily at low speeds compared to high speeds. In my opinion the required braking force should be fairly constant over speed when braking, unless you have a vehicle which has noteable amounts of downforce, which everyday cars don't.
That said - top notch videos, really like the short scientific approach! Been watching your videos for quite a while now.
Sebbl1990 Mass. You have tire and wheel spinning at a higher speed vs a lower speed.
vidurc Well, mass doesn't change when you go faster, does it? At least if you don't consider Einsteins theory of relativity ;-) or changing gear while braking (influence of moment of inertia changes with different gear ratios).
But we can put these aside for my question.
The maximum of brake pressure applied before the wheels lock (or ABS kicks in) should only depend on the vertical wheel loads and the friction coefficient µ. I don't see why the two should change over speed.
Sebbl1990 No the mass doesn't. You however have mass spinning at a higher rate. So the force acting upon it does. When you hit the brakes it causes friction and heat to increase and essentially the friction between the pad and disc is what causes the braking force. So the faster the wheels are turning the more force is require to get it to stop instantaneously. You have a lot more kinetic energy that needs to be removed from the equation to eliminate all the force.
The vertical wheel load and friction coefficient would only be 2 pieces of the puzzle. You are talking about eliminating speed through friction through the use of a stationary component and a moving component coming in contact. The inertia of the moving component still needs to be eliminated in order for it to be stopped completely. With braking force being equal during both applications, the time it takes for friction to build, and braking force to be applied, depends on how quickly said object is moving. This is also the reason why lighter brakes, tires, wheels, and axles can drastically improve braking performance.
Sebbl1990 a brake rotor rotating at higher speeds has more kinetic energy.
Not only does the necessary energy for braking increase with speed, it is also not linear.
E = m*v^2 this means double the speed requires 4 times as much energy to stop
Sebbl1990 he explained it on an earlier post....." Kinetic energy is 1/2mV^2, V being velocity, so the amount of energy required to stop a vehicle moving at 60 mph is 4 times greater than a car moving at 30 mph (rather than two, the relationship is squared not linear)." just think of it this way, when you have something with mass moving, the faster it goes more force is required it is to stop or slow down. Kind of like how some top fuel drag cars require parachutes to slow down rather than just conventional brakes
what about the size of the master cylinder
is the piston size has increased the master cylinder should be increased to move more fluid it requires
So.... Why does high speed braking require more clamping force? Downforce (probably not)? Reduction in pad friction coefficient at high surface speeds/temperatures?
Dual piston just seems like a better option for more evenly pressure. The stagger just seem ridiculous when two can do the same work more effectively.
I have seen people putting multiple calipers on one disc... do you have a interesting video on that?
So we learned that area matters. How about decreasing the "hole" on the piston thus increasing the size of the "wall" and then having a larger area that presses onto the brake pad?
MrThejuzam that changes nothing. what you need is a big area for the brake fluid to press against the piston, not for the piston to press against the brake pad.
brake fluid pressure x Area of piston = clamping force
MrThejuzam heat dissipation and/or transfer to fluid. I am no engineer but I would assume having a greater surface area would also hold in more heat that would also transfer to the fluid pushing the piston which would affect braking performance overall
You mentioned that most brakes are easy to lock up which is why we have ABS, but doesn't that defeat the object of larger callipers, pads etc. ?? Even with more clamping force onto the disc won't the wheels still lock up at the same 'place' if the car has the same contact point (tyres) and grip levels on the road surface?
+gtjack9 Ahh, thanks, makes sense now! :)
can i ask you, where did you learned all that stuff?
And btw i watch all your videos and some of them twice or more ;D
keep up the great work dude:)
Greetings
Dear EE,
In the staggered configuration, the last piston at the end of the arched brake is there to compensate for "inefficiencies" of the first smaller pistons, if I understand well due to speed difference. So why dont you have an array of larger pistons straight away, of maybe big piston small piston, big piston small piston?
My workshop installed a AP Racing CP9202 on the front brakes. The piston is smaller compare to Model CP9200. Is this setup of CP9202 ok for front brakes? The reason is for the allowance for a bigger Rotor of 345mm compare to max 330mm on CP9200
Love the vids bro. Keep it up!
Interesting video as always. Have you or would you look into producing a video the effects of brake upgrades in relation to brake bias and locking wheels.
Totally off the subject but I'm struggling to find information. I have a wrx hawkeye 2007. The boot will not release from the handle inside the car ?
Also the petrol tether ( the plastic bit holding the petrol cap ) has snapped but I can't get a replacement anywhere in the UK without buying the whole petrol cap too ?!
So, the dual pistons on my Legacy 3.6 is for even pad wear and pressure? great video as always !
When and why is it worth it to consider a 6 piston over a 4 piston? Would a 6 piston be overkill for a daily driven street car?
thanks for doing such a great job on all of this incredible information....thanks!
Would 2 sets of 2 piston calipers for the front brakes of a vehicle be sufficient enough for even brake wear on the pads? Thanks, keep up the good work!
thank you for all your helpful videos
I like your explanation methods :)
can you help me with this.. :)
I intend to convert the rear drums to disc brakes..
I would like to hear your advice :)
How do you decrease the likelihood of actual lockup via added pressure? Other than ABS, more downforce, or better tires, are there any other variables to assist in better stopping power without locking up?
Great illustration ,thank you
Is there a difference between single sided two pistons vs oppose sided 4 pistons in terms of the clamping force? If each piston is the same diameter?
Floating caliper has pistons in single side but it has a moving mount the other side. Would it make the clamping force a double in terms of their size of piston surface?
A kind of reverse power steering as brakes? Fluid pressure that’ll slow down, till complete stop, the fan(inside a housing) attached to the wheel?
Question, for a leightweight sportscar (1994 Mazda Miata base) would it be better to have a big brake kit or dual calipers on the rear brakes? This will eventually be a track car but it is my daily driver right now and im interested in tuning it for street applications atm.
Engineering Explained are wheel spacers good for race car or not? and why ?,i have 2010 STI HB and i was planning to get them but i want to know are they good for track or it just give a nice look?
Hi! What do You think - is there a difference between cheap (or just cheaper brake calipers ) vs expensive or top of the line brake calipers? Standard OEM type(style), non performance calipers.
Are there any negative side affects or any advantages to pumping your brakes when coming to a stop these days with the advent of ABS? Thanks. Awesome channel, BTW
I just searched my question and came up with this...
According to the experts:
You do not have to pump your brakes. In fact, if you pump them while braking hard, you will lose the benefits of the ABS.
During emergency hard braking, apply firm pressure to the brake pedal; do not take your foot off the brake until your vehicle comes to a full stop. Essentially, brake and steer.
When the ABS is working, you may notice vibrations/pulsations on your brake pedal and a grinding sound. This is normal and signs that the ABS is engaged.
www.meldonlaw.com/faqs/do-i-have-to-pump-my-breaks-to-keep-from-skidding-if-i-have-an-abs/
Still curious if in everyday driving this will be beneficial or not to the longevity of the pads and rotor.
Can you make video about electric assist power steering?
Even race cars can use normal calipers because the performance calipers are quite expensive and can cost at least 6k. But you will see them mostly on luxury large cars just because they are on the list of optionals and the owners simply click a button and add them. But it isn't that it's a bad thing because it's not wrong to have good brakes.
Good Stuff Great Tips😃👍🏿
Probably worth mentioning you cant increase piston area without changing the master cylinder as you need more volume to move a larger piston.
Is that a floating caliper in the topic of multiple pistons or a fixed caliper?
How does braking effectiveness correlate to temperature? We all know that brakes are less effective when really hot, but are they also less effective when really cold? I've noticed several times driving a long distance on the freeway on a really cold night, having not touched the brakes in as much as an hour and presumably the pads and rotors around freezing or so, I get off the freeway and find the brakes aren't very effective, less than I would expect, but when I'm driving in traffic they grab real good. This isn't any sort of performance pads as far as I know, but the setup isn't power-boosted (it's an old VW Bug converted to disc all around).
Would it be any significant difference and advantage of using a 356mm disc over a 330mm disc with the same caliper and pad?
So in a racing application, which type of calipers would work best? Love your vids...
This is perfect to slow down very good.
So that means the larger number of pistons is only needed for very bigger brake pads, otherwise it wouldn't be necessary to have a 8 pistons brake caliper, in relation to the size of one piston
What's the brake fluid pressure, for high performance brake system?
I have a question. regarding breaks. break pads and rotars as a combination what do you feel is the best for high performance racing level driving? I enjoy taking my car to the track as well and also being how I live in South East Asia and many very stupid drivers on the road here. like to be able to have to same braking safety level on the street as I do on the track. but with so much out there and despite all the information I know. I honestly am not sure anymore what is the best way to go
I clicked back in to give this a like, after noticing the 'Besides Red Paint' quip. :)
I would like to take to you about my challenger and how could I improve it
HOW EASY OR HARD WOULD IT BE TO change the rear calipers on 07 ram 1500 from single piston to double piston like they have on the ram 2500. Could I just change the calipers and it be good. the brake line threads and sizes are the same. I have powerstop pads that were bought using the 1500 model. I am getting a travel trailer soon so I'd like to improve brakes here if I can
Love how he says besides the red paint
0:28 the rubber piston seal is kinda dorked up.
That single piston caliper looks like it's a Girling for a Volvo 940 (with ABS). Is that right?
subscribed. great information. facts only no bull.
Thanks!
but what I would like to know, at the engineering limits which one is best from top to bottom?
@@EngineeringExplained Hi bro! I have a serious question:) If I buy a bigger rotor, will it increase the brake performance? For example, if I have a 288mm rotor and I change it to a 321mm rotor, but I don't change the pads because the manufacturer used the same pads for both rotors. I think, it won't increase the brake performance since I didn't change the surface and I also didn't change the pressure of the brake booster. (As I know my booster can produce 3 kiloNewton) Pls make a whiteBoard explanation:D thanx!
Quick question: What do you do with the automotive parts after you film the video?
DarkMan2555 They sit in my garage until I take the time to install them (which, sometimes is indefinite).
hi, i am wondering about the rotor/axle abuse happening when the outside brake pad on the single piston caliper starts to worn and shrink in size. i guess that the caliper on this setup is fixed and not adjusting to keep the outside pad close to the rotor over time. am i right?? what can you tell us about that concern i just brought up?
+Elie Nehme Brake fluid pressure is what allows the front caliper to adjust to the wear of the brake pad. Single piston, sliding rear calipers tend to ratchet out and that ratcheting action combined with brake fluid pressure is what keeps them constantly adjusting to the brake pad wear.
What makes race grade break pads squeal so much? Do they use metal in the pad?
So can a twinport be the same size as a single port caliper? 🤔
Great brake component tutorials ......
Thank you so much! finally I understand this
great vid!
Please help... What should I use in my racing ATV (dual braking), a diagonal type split braking circuit or "Y type" and why?
So what you're saying is performance brakes and normal brakes will stop in exactly the same time under say 30 mph?
what is the difference in calculation of force on pads when we consider a fixed type caliper having two piston opposite to each other and other having only one piston ?
If I replaced my brake calipers with a bigger pistos, will this affect the abs system? I mean the speed of locking and unlocking due to the larger piston
wouldn't the area in P*A be the brake pad? cuz the pad is what is actually coming in contact with the rotor.