Interesting that this is posted today. During NASCAR practice yesterday, it was noted that due to the heavy cars, 3400+ lbs, small tires and wheels, the brakes generate tremendous heat. The brake rotors and calipers fill nearly all of the space within the small wheel so that most cooling comes from ducting the teams add for cooling. Due to brake technology, the brake systems don't fail anymore but what does happen is that the heat generated from the system gets transferred to the steel wheel and melts the bead of the tire causing tire failure.
jmurphy1973 The wheel acts as a heat sink and when you go to a track day you can definitely feel the wheel heat up. Do NASCAR cars really transfer so much heat to the tires that it melts the rubber? If this were a common occurrence you would see constant tire failure. However that's not the case. The wheel must be acting like a sufficiently effective heat sink to mitigate this.
Sheesh NASCAR is pretty much a drafting contest. Although it might not look like much, it does require a degree in skill especially to know when and when not to brake. I personally am in to motor cross or rally car racing but I've seen these motorsports, they all have their spirits and I respect them equally. But I also like to tease them around :)
Can you possibly do a short video just like this, but with a ventilated rotor?? It would be nice to compare this rotor to a vented one. Maybe we will be able to see the veins inside the rotor heat up and whatnot! Love the videos by the way!
As a brake engineer, yes, aluminum wheels improve brake fade performance vs steel wheels (of course shape of wheel plays a role too). I have never tried carbon fiber yet it should be worse since it's thermal conductivity is typically less than Aluminum. Yet that also depends on the carbon fiber and once again wheel shape.
Are the visibly black paints also good absorbers at IR wavelengths? I guess the IR camera could be used to determine the suitability of the black paint?. I am glad people are discussing this... I had some thoughts about the people that chromed their entire engines... The chromed parts are almost mirrors at visible wavelengths. If that continues for IR wavelengths, they have increased the operating temp of their chromed parts if they are hot parts.
Wheels certainly Can absorb and transfer heat from the brakes of a vehicle. When I worked in a shop, this is one way we were sometimes able to spot brake issues with a customer vehicle when doing inspection during routine services like oil changes and tire rotations. While inspecting brakes for pad thickness, adjusting tire pressure or rotating tires, you can sometimes notice that one wheel is significantly hotter than another (sometimes to the point where you can't touch it bare handed!), or spins much less freely than the other. More often than not when this happens, you would find the pads to be much more worn on that corner, either from a warped rotor or sticking caliper.
Engineering Explained, the only 'issue' after adjusting for the emissivity of the reflective rotor is itll skew the results of the rusted part. Not much you can do when putting everything together in the same picture. I work with thermal cameras for a living and its nice to be able to use it for fun stuff like this as well. Thanks for making this series of vids with the thermal camera.
Gears and Gasoline another interesting thing about thermal cameras is that clear glass acts like a mirror to a thermal image. Visible light can pass through the glass but thermal energy (mostly) gets reflected back.
If the wheel can function as a heat sink for the brakes, could the application of thermal paste between the hub and wheel increase breaking performance? And which kind of wheel would be better for this purpose (shape and material wise)? As a car and PC gaming enthusiast I am exited for what we could learn from this.
out of the wheel material choices given: steel, aluminum, carbon fiber, or magnesium.... aluminum is the best conductor. however, most aluminum wheels are painted to prevent corrosion, the paint can act as an insulator. another factor is the caliper, a heavy steel caliper retains lots of heat while an aluminum one helps dissipate it more quickly.... and the steel one will more likely help contribute to warped rotors over time. as for if a conductive paste would help, not sure try it if you want.
Any paste you apply would probably get squeezed out when you tighten down the wheel, and if you put a thermal spacer it would act like a wheel spacer and change your wheel offset which could hurt suspension performance. And you want the wheel to absorb some of the heat of the brakes to help with cooling, but only up to a certain point and after the wheels get too hot it heats up the tires too much and can hurt your tire's grip.
It has been my experience as a parking lot racer (SCCA Solo 2) and as a Pro Rally racer, that wheels do in fact work as a heat sink for brakes (aluminum vs. steel). One thing I was never able to determine was at what temperature do brake pads catch fire. As I recall, toward the end of the 3rd stage at the STPR rally in Pennsylvania, it was a tight twisting road racing down hill, and I would be a little too heavy left foot braking, and would come into the Finish Control with my front brake pads aflame. the full metallic pads and Brembo rotors would still be working fine, and I would finish the event without changing them (the pads), the bonding agent of the pads would be compromised, and would soon crumble apart. Videos easily show Rally Cars blasting through corners with glowing rotors, but as far as I know, I'm the only one that was able to ignite my brake pads. When fellow competitors commented that their brake did not catch fire, I simply asked them to compare our Stage times.
this is why F1's are hard on their brakes during their warmup lap, the heat generated will transfer to the tires, warming them up, it isn't just about the friction on the ground, but the brakes keep them warm as well
I was also amazed the camera detected run out that was not enough to cause a noticeable vibration. It would be interesting to know how much run out produced the graphic result you experienced. Another great video.
0:27 super interesting that the reflection of your leg shows up as bright as it does on the brake rotor. Can't imagine the rotor is heating up instantaneously from your leg passing by but it does go to show the infrared coming off your leg truly acts just like light (EM wave) and reflects off a mirror-like surface. On an unrelated note, the rest of the video is interesting too.
When you brake without a wheel, the little screw holding the brakedisc on the axle has to handle with all the torque. With a wheel fitted on the axle, the force is transmitted by the Wheelnuts/bolts. The tiny screw is just for centering (holes in disc are bigger than wheelbolts) and holding the disc when there is no rim to prevent it from falling of.
Pretty interesting that the wheels themselves can act as a heat sink and cool the brakes. I just did a Brembo brake swap on my 240sx and posted a how to on my channel. I've got a thermal gun and it it will be pretty cool to see what temps they reach on a track day:
There's so many potential things to do with this camera! Never really thought about the fact that brake fluid can get quite hot under certain circumstances before.
I am loving these thermal videos, great visualization of water is going on in cars. I am money is on aluminium wheels at the better material, since the metal transfer heat quickly and is lighter than steel.
dude it didnt ocurr to me that rim material would interact with break disc hrat dissipation! thats pretty cool, and an insight into professional racing .
I'm trying to work out some carbon rotors on my Elise. If they ever become operational, you're more than welcome to come over and get some footage of the carbon rotors in action.
you're screwing with me man!!! i need you to do more car reviews....You're car reviews are one of a kind !! VERY DIFFERENT THAT ALL OF THESE FAKE CAR ENTHUSIASTS!!
Cool! I'm happy, I did asked for this ( not like Jensen) lol. It,s cool the see wheel helping brake cooling. I know that some sport car car have their wheel design with cooling and air flow towards the brake in minds. They can act as fans. This might increase the air resistance thought. Heat is such a huge part of everything about cars, is fun to be able to see it. Thanks
You'll see many modern race cars actually warming their tires with the brakes. In fact, it is absolutely the best way to warm up the rubber. The only downside is it wastes fuel, so endurance racers are more likely to continue cornering hard to do the same thing.
something I'd really like to see would be the warm up of a hot V engine vs a conventional V engine, along with their respective intake temperatures, an. engineering explained on hot V engines would be interesting as well showing the pros/cons of the setup
Jason, thank you for the very informative video. As others have alluded to below, the camera may be helpful for investigating possible causes of rotor warpage. Our 2007 Honda Odyssey warps rotors every couple of years, and the exact cause has been a source of debate in my house.
Hey ! Very nice video. Can you record the temperature of the rotor during hard brake ? For example accelerate at 60 mph (on speedometer) and hit the brake until the rotor stop to get an idea the amount of energy absorbed by the rotor. Thanks !
Hey Jason. Just read an article about a new 2018 Hellcat having a system called "Torque Reserve." Seems ambitious. The idea is keeping the supercharger spinning while at a stop with the clutch open in order to boost similar to a turbo. If your master skills can break it down for me in a video, it would be a really good video to watch because I am very curious. TLDR: NEW VIDEO: "Torque Reserve"
Very informative and a great video. I’m sure that alloy wheels or other suck stuff would in fact cool the brakes faster. They usually have a lot more space or air spaces for the air to pass between them. I would also be very interested to know if the claims behind drilled rotors is true. Some even claim differences of up to 150 degrees in their drilled rotors.
i heard a while back that a company looking into carbon fibre wheels were concerned about about the heat transfer rate compared to metallic wheels and what it would mean for the cooling of the brakes, as I think it goes without saying, these wheels would likely be on higher performance vehicles and the heat transfer would be a lot more crucial.
Jason, first off I'm a huge fan of your vids and have learned a substantial amount of the years. this particular vid has raised some questions that your mechanical engineering mindset may be able to answer. scenario: in my Mazdaspeed3 I have recently replaced my pads rotors. I failed to clean the mating surface of the rotor and hub as well as properly installing the pad retaining springs on the pad the first time around. with the car jacked up I notice a significant amount of run-out which causes judder at high speeds. they do not judder at low speed braking my poor installation techniques have also led to the 10,000 mile old rotors to have grooves across the surface. now here's my question. when doing numerous high speed braking, what would cause the judder to worsen at high speeds and be noticeable at low speeds? obviously heat is a factor here because once the system cools the problem dissolves. I was hoping to see some sort of engineering explained type of answer as Google searches have failed me here. Thanks
So my old classy turbine-style alloy wheels are probably about the equivalent of my CPU cooler. Neat. On the other side of the thermal spectrum, having too much water in the brake fluid will also cause it to start freezing. It happened to me at 4% water content.
Hey Jason it's Luke, you met me. I forgot to thank you for helping people like me by uploading your videos. I also want to thank you for taking time from your vacation to talk about your work haha. It really means a lot. Enjoy your vacation! Also! I was really angry I didn't get a picture haha. Ah well. Thanks again! Your the best.
the parking brake acts on the hub and works like a drum brake that is why the rear disk brakes on cars are not just a flat disk but have the center part. this is why the pad remains cold and the brake fluid remains cold. It is also why the center hub area gets very hot vs the rotor and everything else. Wheels tend to act more like a fan than a heat sink.
It would be interesting if vehicles had some kind of temperature sensors on the rotors to let drivers know when their brakes were just starting to overheat. That way the driver would know to pull-over for a few minutes, or to down-shift. This becomes really critical when towing, and could save a lot of lives for people who get surprised by brake-fade when driving in the mountains.
I heard that duct tape would show the correct temperature of a metal, however, it would need to cover a lot of the brakes or else it would be hard to see the color/temperature of the tape since it would be rotating so quickly. If you used a lot of duct tape, then the temperature won't dissipate into the air as well.
I'll be honest, I usually get annoyed with some of your videos, but this one is a thoughtful and useful one... I never really looked at wheels as anything other than something you absorb bumps on the road with, whereas now, I can see that there's an additional benefit of having a forged aluminum wheel... it'll be able to absorb and dissipate heat more effectively, thereby keeping the brakes cooler. Would've thought that the type of wheel material, solely, would aid in the cooling of your brakes on a track day?
Now those are interesting datapoints! Thanks for sharing them and how much heat the brakes create. This can explain why electric and hybrid (the later being more complicated!) cars can take advantage of the heat conducted from those breaks. I'm pretty sure aluminum wheels can provide a good heat sink for those wheels, unless the paint is a minor insulator.
You should test the Tesla Turbine Wheel design, to see if it makes a dramatic difference in cooling compared to a standard 5 spoke wheel design and a custom wheel design... I think that'd make for an interesting video alongside your wheel material one! :D
Was driving on a highway and frequently used the brakes. The minute I got home I washed my car and was panicking because the front wheels were smoking. I saw it coming from the brakes and touched it and boi was it hot as hell. After cleaning my ride I proceeded to watch this video.
Yes very interesting well set up video. However, what I was looking for was the normal running temperatures BEFORE the brakes are actually applied. The drag in other words. How much residual drag is normal?
Were you able to verify if that rotor runout was legitimate, or a camera trick? Also, super cool to see the reflectivity of the brake rotor at 3:15 - you can clearly see the backside of the wheel reflected in the rotor. It wouldn't have applied in this case, but a common technique when dealing with infrared temperature measurement on shiny surfaces is to put a dull black sticker, or a small bit of paint and measure the temperature at that point.
Now you need to make a video on wheel material as it relates to heat dissipation from the brake rotors. I'm extremely curious now but I can't afford a fancy thermal camera. I would imagine steel would absorb more in the short term but aluminum would dissipate more overall.
Thermal conductivity of aluminum is fairly high. Aluminum is often used for heatsinks. It appears the thoretical thermal conductivity of a graphene wheel would be extremely high.
shoot. i got lucky last week that somehow one rear brake caliber was to say broken as it stayed somewhat stuck to the rotors. that grinding sound while driving sure made it hot. luckily i had drilled and slotted rotors to keep it from further damages
a pure-ish aluminum alloy is likely the best for wheels. its got high thermal conductivity and high relative thermal mass (unit heat energy per degree per unit mass) plus it's strong too. magnesium would be pretty good as well
I've noticed that with my car. After a bit of 'spirited' driving, the alloys themselves get fairly warm. It must aid with brake heat dissipation I guess.
I might or might not get apply for a bachelor's thesis regarding heat distribution and heat induces cracking of large steel brake discs. I always thought that steel was very resiliant to heat gradients, unlike glass. Could you please explain the mechanism behind that problem?
Can you please do one on the intercooler temperature gradient and show how significant the difference in intake air temperature is with and without an intercooler ?
Cool video, but most parking brakes don't use the calipers on the rear wheels at all. They apply a drum brake to the inside of the rotor. This would account for the higher temperatures at the center of the rotor, hub, and rims. Still a great video.
While drum in hat parking brakes are certainly popular I do believe the Honda S2000 uses a caliper with an integrated parking brake (it's a cam mechanism that applies the brakes mechanically).
During hard braking to stop at a light or otherwise and you keep the brake pedal depressed once stopped, does it cause significant heat damage / warping of the rotor? I always try to put the car in neutral if on level ground to prevent this... but maybe it's not a problem. Thanks! Very cool video! Good to see you're getting use of your thermal camera.
Keith Price Not when you're driving on the street. If you're doing hot laps at a track and you pull off and apply the parking brakes you can easily warp the rear rotors however.
Keith Price never do this on the street. If another car hits you then your car will go flying out of control, probably hitting other cars. Always keep brakes applied while stopped in traffic. I drive manual gearbox and always have the gearbox in neutral but with brakes applied while stopped in traffic.
Always keep your brakes applied while stopping at red light.... It doesn't generate heat or wear out your brakes since your car isnt't moving and there's no friction. Common sense.....
I just serviced the break on my 2008 Ford explorer. Driving it through a mountainous region in Haiti, the driver could smell the break getting hot. After a few minutes, the driver lost control of the car, and the break will not respond in any way applied. Since the car was going downhill, the driver managed to stop the car by driving the passenger side against a wall. The finally stopped leaving driver, and passenger unconscious. Since the break system was brand new, what could make it fail so suddenly.
There seems to be a debate between variable rotor thickness and warped rotors. Would you be willing to make a video to settle the debate, please? I need to know if I am doing something wrong with my 2002 Toyota Sienna. I also need to know if **must** fix the problem, or just wait until my brake pads wear out, or whatever. I bought this van as a beater car for my day job work. I'm a new car owner, so i want to learn before I buy a car that I care about.
Jason, I like the video. Great idea to show how this all transferred heat. It made me think of carbon rotors and magnesium wheels would be effective in this situation. Then I realized what issue could be leading to what looks like the higher temperature coming from the hub. Isn't the handbrake activating a drum break inside the hub?
Brakes get pretty hot on the cars and trucks coming down Teton Pass. I can smell them burning on the vehicles in front of me, especially the drum brakes on RVs.
Yeah, that and braking hard and fast, like, your going at 60mph, brake hard to 40, regain momentum to 60 and do it again, this is what GOOD truckers does, otherwise they will ruin the brakes.
B10401, Iam from Sweden, so it might not be the right word, but they are getting polished almost.. Like, they are slippery instead of dull / matt, often when trucks are in a repairshop for brakes, its because just that, they have become polished by the heat of the brakepad during light braking when going down a hill for example.
Well, if you lightly drag, you will increase the heat the further you go, but if you brake hard (Just a couple of seconds) and release, the heat wont be that massive, iam amazed that he didnt bring this up since this is actually a huge deal. Going down a hill you do not want to overspeed haha, go down from 60 to 40, then coast down the hill till you go to 60 again ^^
I'm surprised to see how much the wheel act as an heatsink ! Cheap car equiped with crap brakes and basic wheels with hubcovers may have such bad braking performances ! Plus I'have got some questions for you : Could hybrid/electric (turbo)charger replace the throttle body ? What make motorcycle engines so small compared to equivalent power car engines ?
If you do supercharge your s2000, you should drag race against Saabkyle04's soon-to-be turbocharged 240sx. Also, when you complete your build, it would be cool to see how it performs on the track.
Interesting that this is posted today. During NASCAR practice yesterday, it was noted that due to the heavy cars, 3400+ lbs, small tires and wheels, the brakes generate tremendous heat. The brake rotors and calipers fill nearly all of the space within the small wheel so that most cooling comes from ducting the teams add for cooling.
Due to brake technology, the brake systems don't fail anymore but what does happen is that the heat generated from the system gets transferred to the steel wheel and melts the bead of the tire causing tire failure.
jmurphy1973 That's neat.
jmurphy1973 The wheel acts as a heat sink and when you go to a track day you can definitely feel the wheel heat up. Do NASCAR cars really transfer so much heat to the tires that it melts the rubber? If this were a common occurrence you would see constant tire failure. However that's not the case. The wheel must be acting like a sufficiently effective heat sink to mitigate this.
I dont really get nascar. Subpar cars, nothing that could be called "track" and thats basically it. Why do people do that?! lel
Sheesh NASCAR is pretty much a drafting contest. Although it might not look like much, it does require a degree in skill especially to know when and when not to brake. I personally am in to motor cross or rally car racing but I've seen these motorsports, they all have their spirits and I respect them equally. But I also like to tease them around :)
Not every week the teams race in 95 degree temps, like they are encountering this week in Phoenix.
Can you possibly do a short video just like this, but with a ventilated rotor?? It would be nice to compare this rotor to a vented one. Maybe we will be able to see the veins inside the rotor heat up and whatnot! Love the videos by the way!
As a brake engineer, yes, aluminum wheels improve brake fade performance vs steel wheels (of course shape of wheel plays a role too). I have never tried carbon fiber yet it should be worse since it's thermal conductivity is typically less than Aluminum. Yet that also depends on the carbon fiber and once again wheel shape.
Cool story bro.
200°C .... try this same thing on a Chevrolet Cargo Van, they will probably be 400°C, they are very undersized IMO.
ayo 6 yrs ago and no replies ?
Ok
that's really cool....can you do one on exhaust system ( tailpipe + muffler + catalytic converter, etc ).....
+Sachin Dangi yes, this will happen! :)
Are the visibly black paints also good absorbers at IR wavelengths? I guess the IR camera could be used to determine the suitability of the black paint?.
I am glad people are discussing this... I had some thoughts about the people that chromed their entire engines... The chromed parts are almost mirrors at visible wavelengths. If that continues for IR wavelengths, they have increased the operating temp of their chromed parts if they are hot parts.
Wheels certainly Can absorb and transfer heat from the brakes of a vehicle.
When I worked in a shop, this is one way we were sometimes able to spot brake issues with a customer vehicle when doing inspection during routine services like oil changes and tire rotations. While inspecting brakes for pad thickness, adjusting tire pressure or rotating tires, you can sometimes notice that one wheel is significantly hotter than another (sometimes to the point where you can't touch it bare handed!), or spins much less freely than the other. More often than not when this happens, you would find the pads to be much more worn on that corner, either from a warped rotor or sticking caliper.
That was incredibly interesting! Thanks for the insight Jason! Does the reflective surface of the rotor skew the data?
Somewhat, yes, but you can calibrate the camera for it and get pretty darn close.
Engineering Explained, the only 'issue' after adjusting for the emissivity of the reflective rotor is itll skew the results of the rusted part. Not much you can do when putting everything together in the same picture. I work with thermal cameras for a living and its nice to be able to use it for fun stuff like this as well. Thanks for making this series of vids with the thermal camera.
Gears and Gasoline another interesting thing about thermal cameras is that clear glass acts like a mirror to a thermal image. Visible light can pass through the glass but thermal energy (mostly) gets reflected back.
If the wheel can function as a heat sink for the brakes, could the application of thermal paste between the hub and wheel increase breaking performance? And which kind of wheel would be better for this purpose (shape and material wise)? As a car and PC gaming enthusiast I am exited for what we could learn from this.
ElZamo92 asking the real question there
ElZamo92 you could be onto something
I thunk some thermal grizzly conductonaut will do the trick and maybe if u lap the wheel hub it will help the cooling efficiency
out of the wheel material choices given: steel, aluminum, carbon fiber, or magnesium.... aluminum is the best conductor. however, most aluminum wheels are painted to prevent corrosion, the paint can act as an insulator. another factor is the caliper, a heavy steel caliper retains lots of heat while an aluminum one helps dissipate it more quickly.... and the steel one will more likely help contribute to warped rotors over time. as for if a conductive paste would help, not sure try it if you want.
Any paste you apply would probably get squeezed out when you tighten down the wheel, and if you put a thermal spacer it would act like a wheel spacer and change your wheel offset which could hurt suspension performance.
And you want the wheel to absorb some of the heat of the brakes to help with cooling, but only up to a certain point and after the wheels get too hot it heats up the tires too much and can hurt your tire's grip.
You should do drum breaks too! See which ones cool down faster, the differences in operation, types of other beaks, etc.!
It has been my experience as a parking lot racer (SCCA Solo 2) and as a Pro Rally racer, that wheels do in fact work as a heat sink for brakes (aluminum vs. steel). One thing I was never able to determine was at what temperature do brake pads catch fire. As I recall, toward the end of the 3rd stage at the STPR rally in Pennsylvania, it was a tight twisting road racing down hill, and I would be a little too heavy left foot braking, and would come into the Finish Control with my front brake pads aflame. the full metallic pads and Brembo rotors would still be working fine, and I would finish the event without changing them (the pads), the bonding agent of the pads would be compromised, and would soon crumble apart. Videos easily show Rally Cars blasting through corners with glowing rotors, but as far as I know, I'm the only one that was able to ignite my brake pads. When fellow competitors commented that their brake did not catch fire, I simply asked them to compare our Stage times.
who thought thermal cam is this useful ,you are a real creative engineer Jason .
This was really informative. I love that you can see whether or not a rotor is warped. The Flir camera seems like a very useful tool.
this is why F1's are hard on their brakes during their warmup lap, the heat generated will transfer to the tires, warming them up, it isn't just about the friction on the ground, but the brakes keep them warm as well
I was also amazed the camera detected run out that was not enough to cause a noticeable vibration. It would be interesting to know how much run out produced the graphic result you experienced. Another great video.
0:27 super interesting that the reflection of your leg shows up as bright as it does on the brake rotor. Can't imagine the rotor is heating up instantaneously from your leg passing by but it does go to show the infrared coming off your leg truly acts just like light (EM wave) and reflects off a mirror-like surface. On an unrelated note, the rest of the video is interesting too.
When you brake without a wheel, the little screw holding the brakedisc on the axle has to handle with all the torque. With a wheel fitted on the axle, the force is transmitted by the Wheelnuts/bolts. The tiny screw is just for centering (holes in disc are bigger than wheelbolts) and holding the disc when there is no rim to prevent it from falling of.
See 0:00 - 0:07 for the smaller bolts and the tiny screw.
+1 Some nuts should holds the disk. Less vibration, more honest test.
Pretty interesting that the wheels themselves can act as a heat sink and cool the brakes. I just did a Brembo brake swap on my 240sx and posted a how to on my channel. I've got a thermal gun and it it will be pretty cool to see what temps they reach on a track day:
you're having way to much fun with this thermal camera
There's so many potential things to do with this camera! Never really thought about the fact that brake fluid can get quite hot under certain circumstances before.
Really cool to see the IR reflection of the wheel in the brake rotor! Great video, Jason!
Would have been cool if you put a fan blowing past the side of the car to replicate airflow while driving
Potential video topic: always use parking brake? even in an automatic not on a hill?
Pros and cons of disc versus drum brakes?
I am loving these thermal videos, great visualization of water is going on in cars. I am money is on aluminium wheels at the better material, since the metal transfer heat quickly and is lighter than steel.
dude it didnt ocurr to me that rim material would interact with break disc hrat dissipation! thats pretty cool, and an insight into professional racing .
I knew breaks got hot but never knew how hot. Thanks for the video!!
I'm trying to work out some carbon rotors on my Elise. If they ever become operational, you're more than welcome to come over and get some footage of the carbon rotors in action.
The type of wheel to influence dissipation would be pretty interesting to see
you're screwing with me man!!! i need you to do more car reviews....You're car reviews are one of a kind !! VERY DIFFERENT THAT ALL OF THESE FAKE CAR ENTHUSIASTS!!
Engineering Explained, i love your videos man. Well done once again.
+Ka1Winters thank you!
Cool! I'm happy, I did asked for this ( not like Jensen) lol. It,s cool the see wheel helping brake cooling. I know that some sport car car have their wheel design with cooling and air flow towards the brake in minds. They can act as fans. This might increase the air resistance thought. Heat is such a huge part of everything about cars, is fun to be able to see it. Thanks
I think I've just seen the most useful TH-cam advert before this video... Nissan tire repair kit roadside use :) that I can watch
You'll see many modern race cars actually warming their tires with the brakes. In fact, it is absolutely the best way to warm up the rubber. The only downside is it wastes fuel, so endurance racers are more likely to continue cornering hard to do the same thing.
this guy the homie. had to pop the comment like situation.
I'm trying to learn about drum brakes and disk brake temp differences.
something I'd really like to see would be the warm up of a hot V engine vs a conventional V engine, along with their respective intake temperatures, an. engineering explained on hot V engines would be interesting as well showing the pros/cons of the setup
Jason, thank you for the very informative video. As others have alluded to below, the camera may be helpful for investigating possible causes of rotor warpage. Our 2007 Honda Odyssey warps rotors every couple of years, and the exact cause has been a source of debate in my house.
Sticking brake pad. Probably the inner one. I have the same issue on my Honda, then found out that was the problem.
Hey ! Very nice video. Can you record the temperature of the rotor during hard brake ? For example accelerate at 60 mph (on speedometer) and hit the brake until the rotor stop to get an idea the amount of energy absorbed by the rotor. Thanks !
Hey Jason. Just read an article about a new 2018 Hellcat having a system called "Torque Reserve." Seems ambitious. The idea is keeping the supercharger spinning while at a stop with the clutch open in order to boost similar to a turbo. If your master skills can break it down for me in a video, it would be a really good video to watch because I am very curious. TLDR: NEW VIDEO: "Torque Reserve"
Very informative and a great video.
I’m sure that alloy wheels or other suck stuff would in fact cool the brakes faster. They usually have a lot more space or air spaces for the air to pass between them.
I would also be very interested to know if the claims behind drilled rotors is true. Some even claim differences of up to 150 degrees in their drilled rotors.
i heard a while back that a company looking into carbon fibre wheels were concerned about about the heat transfer rate compared to metallic wheels and what it would mean for the cooling of the brakes, as I think it goes without saying, these wheels would likely be on higher performance vehicles and the heat transfer would be a lot more crucial.
Thanks Jason, have a good days.
You're having WAY too much fun with that FLIR camera... lol
I wonder if thermal paste between the wheel and the brake rotor would help transfer the heat into the rim. Could be a cool experiment.
Jason,
first off I'm a huge fan of your vids and have learned a substantial amount of the years.
this particular vid has raised some questions that your mechanical engineering mindset may be able to answer.
scenario: in my Mazdaspeed3 I have recently replaced my pads rotors. I failed to clean the mating surface of the rotor and hub as well as properly installing the pad retaining springs on the pad the first time around. with the car jacked up I notice a significant amount of run-out which causes judder at high speeds. they do not judder at low speed braking my poor installation techniques have also led to the 10,000 mile old rotors to have grooves across the surface.
now here's my question. when doing numerous high speed braking, what would cause the judder to worsen at high speeds and be noticeable at low speeds?
obviously heat is a factor here because once the system cools the problem dissolves. I was hoping to see some sort of engineering explained type of answer as Google searches have failed me here.
Thanks
Interesting to see the wheel heat up. I had a sticky brake, which I continually checked by feeling the bolts.
Just when I thought this channel couldn't possibly get any cooler! Hahaha.
So my old classy turbine-style alloy wheels are probably about the equivalent of my CPU cooler. Neat.
On the other side of the thermal spectrum, having too much water in the brake fluid will also cause it to start freezing. It happened to me at 4% water content.
So, what would it take to start seeing a rise in the temperature of the brake fluid? (fascinating video, btw)
I just learned a lot. Good vid man. Simple and effective
Hey Jason it's Luke, you met me. I forgot to thank you for helping people like me by uploading your videos. I also want to thank you for taking time from your vacation to talk about your work haha. It really means a lot. Enjoy your vacation! Also! I was really angry I didn't get a picture haha. Ah well. Thanks again! Your the best.
THANK YOU for doing this in C (not that ghastly F scale)!
It would be interesting to see this but with different types of rotors like slotted, vented vs non vented
the parking brake acts on the hub and works like a drum brake that is why the rear disk brakes on cars are not just a flat disk but have the center part. this is why the pad remains cold and the brake fluid remains cold. It is also why the center hub area gets very hot vs the rotor and everything else. Wheels tend to act more like a fan than a heat sink.
Helpful for car maintainance
nice video as always james
This was a freakin cool video and that question at the end is totally one worthwhile...
It would be interesting if vehicles had some kind of temperature sensors on the rotors to let drivers know when their brakes were just starting to overheat. That way the driver would know to pull-over for a few minutes, or to down-shift. This becomes really critical when towing, and could save a lot of lives for people who get surprised by brake-fade when driving in the mountains.
I heard that duct tape would show the correct temperature of a metal, however, it would need to cover a lot of the brakes or else it would be hard to see the color/temperature of the tape since it would be rotating so quickly. If you used a lot of duct tape, then the temperature won't dissipate into the air as well.
I'll be honest, I usually get annoyed with some of your videos, but this one is a thoughtful and useful one... I never really looked at wheels as anything other than something you absorb bumps on the road with, whereas now, I can see that there's an additional benefit of having a forged aluminum wheel... it'll be able to absorb and dissipate heat more effectively, thereby keeping the brakes cooler. Would've thought that the type of wheel material, solely, would aid in the cooling of your brakes on a track day?
Now those are interesting datapoints! Thanks for sharing them and how much heat the brakes create. This can explain why electric and hybrid (the later being more complicated!) cars can take advantage of the heat conducted from those breaks. I'm pretty sure aluminum wheels can provide a good heat sink for those wheels, unless the paint is a minor insulator.
You should test the Tesla Turbine Wheel design, to see if it makes a dramatic difference in cooling compared to a standard 5 spoke wheel design and a custom wheel design... I think that'd make for an interesting video alongside your wheel material one! :D
Was driving on a highway and frequently used the brakes. The minute I got home I washed my car and was panicking because the front wheels were smoking. I saw it coming from the brakes and touched it and boi was it hot as hell. After cleaning my ride I proceeded to watch this video.
I enjoy your videos and find them interesting and informative.
Yes very interesting well set up video. However, what I was looking for was the normal running temperatures BEFORE the brakes are actually applied. The drag in other words. How much residual drag is normal?
Were you able to verify if that rotor runout was legitimate, or a camera trick? Also, super cool to see the reflectivity of the brake rotor at 3:15 - you can clearly see the backside of the wheel reflected in the rotor. It wouldn't have applied in this case, but a common technique when dealing with infrared temperature measurement on shiny surfaces is to put a dull black sticker, or a small bit of paint and measure the temperature at that point.
Now you need to make a video on wheel material as it relates to heat dissipation from the brake rotors. I'm extremely curious now but I can't afford a fancy thermal camera. I would imagine steel would absorb more in the short term but aluminum would dissipate more overall.
Aluminum is better and it's not even close. It also helps Aluminum wheels are typically more open.
Extremely good information
Your thumbnail had me worried! Glad to see that it was a FLIR image.
Thermal conductivity of aluminum is fairly high. Aluminum is often used for heatsinks. It appears the thoretical thermal conductivity of a graphene wheel would be extremely high.
u will need thermal paste to help heat transfer from the wheel hub to the wheel. also it would work even better if u polished the area of contact.
Could you do the same for drum brakes?
shoot. i got lucky last week that somehow one rear brake caliber was to say broken as it stayed somewhat stuck to the rotors. that grinding sound while driving sure made it hot. luckily i had drilled and slotted rotors to keep it from further damages
Do drilled and slotted brakes next! 👍
a pure-ish aluminum alloy is likely the best for wheels. its got high thermal conductivity and high relative thermal mass (unit heat energy per degree per unit mass) plus it's strong too. magnesium would be pretty good as well
Another great reason to get magnesium/aluminum wheels besides weight reduction.
As more heat causes brake fade/failure, what thing is failing? Brake pads? Boiling brake fluid?
Great video, keep up the good work.
I've noticed that with my car. After a bit of 'spirited' driving, the alloys themselves get fairly warm. It must aid with brake heat dissipation I guess.
love your videos man keep it up!!!
Like a kid at Christmas with this FLIR camera. I can't really blame him though, I would be the same.
u should hv taken a shot with the tires on , only to se how much does the tire helps in cooling the break pad
but gr8 vid
thank you for this illustration
can you make video about why diesel engines have more torque then petrol
I might or might not get apply for a bachelor's thesis regarding heat distribution and heat induces cracking of large steel brake discs. I always thought that steel was very resiliant to heat gradients, unlike glass. Could you please explain the mechanism behind that problem?
Can you please do one on the intercooler temperature gradient and show how significant the difference in intake air temperature is with and without an intercooler ?
Cool video, but most parking brakes don't use the calipers on the rear wheels at all. They apply a drum brake to the inside of the rotor. This would account for the higher temperatures at the center of the rotor, hub, and rims. Still a great video.
While drum in hat parking brakes are certainly popular I do believe the Honda S2000 uses a caliper with an integrated parking brake (it's a cam mechanism that applies the brakes mechanically).
During hard braking to stop at a light or otherwise and you keep the brake pedal depressed once stopped, does it cause significant heat damage / warping of the rotor?
I always try to put the car in neutral if on level ground to prevent this... but maybe it's not a problem.
Thanks! Very cool video! Good to see you're getting use of your thermal camera.
Keith Price I'll leave this here, for an answer
Keith Price Not when you're driving on the street. If you're doing hot laps at a track and you pull off and apply the parking brakes you can easily warp the rear rotors however.
Keith Price i need the answeeeeer.
Keith Price never do this on the street. If another car hits you then your car will go flying out of control, probably hitting other cars. Always keep brakes applied while stopped in traffic. I drive manual gearbox and always have the gearbox in neutral but with brakes applied while stopped in traffic.
Always keep your brakes applied while stopping at red light.... It doesn't generate heat or wear out your brakes since your car isnt't moving and there's no friction. Common sense.....
great video as always
keep up doing good work!
This was a great test/observation. can you do it again at some point with aftermarket performance pads and rotors? thanks
I just serviced the break on my 2008 Ford explorer. Driving it through a mountainous region in Haiti, the driver could smell the break getting hot. After a few minutes, the driver lost control of the car, and the break will not respond in any way applied. Since the car was going downhill, the driver managed to stop the car by driving the passenger side against a wall. The finally stopped leaving driver, and passenger unconscious. Since the break system was brand new, what could make it fail so suddenly.
Please do a vídeo with a perforated disc in order to compare its efficiency
It would be cool if you could do this with a comparison of stock rotors vs 2 piece rotors, and stock vs drilled or slotted rotors!
There seems to be a debate between variable rotor thickness and warped rotors. Would you be willing to make a video to settle the debate, please?
I need to know if I am doing something wrong with my 2002 Toyota Sienna. I also need to know if **must** fix the problem, or just wait until my brake pads wear out, or whatever. I bought this van as a beater car for my day job work. I'm a new car owner, so i want to learn before I buy a car that I care about.
Jason, I like the video. Great idea to show how this all transferred heat. It made me think of carbon rotors and magnesium wheels would be effective in this situation. Then I realized what issue could be leading to what looks like the higher temperature coming from the hub. Isn't the handbrake activating a drum break inside the hub?
Jason Dahlstrom Honda e-brakes actuate the caliper with a spring linkage behind it. No drums here.
Oh, I see. Just every rear brake job I've done had a drum. Thanks for the clarification.
Brakes get pretty hot on the cars and trucks coming down Teton Pass. I can smell them burning on the vehicles in front of me, especially the drum brakes on RVs.
Yeah, that and braking hard and fast, like, your going at 60mph, brake hard to 40, regain momentum to 60 and do it again, this is what GOOD truckers does, otherwise they will ruin the brakes.
B10401, Iam from Sweden, so it might not be the right word, but they are getting polished almost.. Like, they are slippery instead of dull / matt, often when trucks are in a repairshop for brakes, its because just that, they have become polished by the heat of the brakepad during light braking when going down a hill for example.
And instead of having good brakes, you will hear them ''whine'' and have poor braking.
Well, if you lightly drag, you will increase the heat the further you go, but if you brake hard (Just a couple of seconds) and release, the heat wont be that massive, iam amazed that he didnt bring this up since this is actually a huge deal. Going down a hill you do not want to overspeed haha, go down from 60 to 40, then coast down the hill till you go to 60 again ^^
In the beginning I thought he was gonna say "Hello everyone, this is YOUR daily dose of internet"
I'm surprised to see how much the wheel act as an heatsink ! Cheap car equiped with crap brakes and basic wheels with hubcovers may have such bad braking performances !
Plus I'have got some questions for you :
Could hybrid/electric (turbo)charger replace the throttle body ?
What make motorcycle engines so small compared to equivalent power car engines ?
There is a clean strip on the rusty surface what makes it look like it warmer in the begining.
Do the wheel type difference video! That's be sweet!
If you do supercharge your s2000, you should drag race against Saabkyle04's soon-to-be turbocharged 240sx.
Also, when you complete your build, it would be cool to see how it performs on the track.
Thanks for the video, especially after the last video comments
You didn't mention magnesium wheels ;D
And I would bet a comparison would:
A) challenging to perform
B) have interesting results