We progressively cross drill Lada brake rotors - what will happen?
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- Опубліковано 5 вер 2024
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In this video we do a bit of custom cross drilling. Some of the results were fairly predictable, but at times we were genuinely surprised.
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Most of the loss in distance between tests could be attributed to the pads and rotors bedding together and working better after some stops. Brand new pads on brand new rotors always stop more poorly for a period of time and a few heat cycles before they're at peak performance.
That’s what I’m thinking.
Properly bedded brakes will transfer some material to the rotor face. I don't think there actually needs to be more friction. Lots of brake systems on a car are actually way oversized where you can lock the tire at will.
@@timothybayliss6680 Yeah, if the wheels can lock, the brake is powerful enough and the stopping distance depends on the rest (like weight and grip). The cooling advantage likely isn't appreciated at a highest temperature of 100-ish degrees Celcius. They would barely steam up water that hits them, nowhere near fading point.
@@Kalvinjj prolonged heat generates brake fade. Not common in a regular car unless you are severely speeding.
Get a car up to 100mph+ and firmly apply the brakes, before you can stop you will have to slam on the pedal to get wheel lockup. Do it again and you can push with ALL your might on the brakes and it feels like you lost 50% of your brake power and you can't lock up a wheel or activate abs if your life depended on it.
Brakes are certainly oversized for driving within the speed limits, but once you exceed that and really test the brakes you know how little energy they can dump. Which is how trucks get into trouble going down hills. Hot brakes barely work, and with a heavy vehicle it's even worse.
extra heat is good, too...b/c russia LOL
I suspect a lot of the initial decrease in braking distance had little to do with the holes and more to do with the pads bedding in.
Or the sharp edges or the holes digging into the pads better, while more uses create a rounder edge.
yeah and holes should be bored at a angle too so it dosnt dig the pads in and the air circulates outwards ,its more precise than what theyre doing
@@girlsdrinkfeck At an angle? Why? They're countersunk to avoid needing to drill them at angles.
With all the holes drilled the pads have less gripping force.
@@RenoBusdriver yep. Then add in even more surface area gone due to the large countersinks. Really wasn't much surface area left at all after that.
When you take away rotor surface area (drilling holes) you take away the ability of the brake pad to have something to push against (called brake effort). As you found out, there was a test where a small amount of holes reached the maximum brake effort. All the best guys.
Less friction area
Also, it's now not a very smoothe surface, you can hear the clickity clack sounds, each hole can be compared to a bump or pothole in the road just like it makes your car bounce they are making the brake pad bounce and each bounce it makes it's not properly uniformally compressing the rotor as it should compounding with what you said above, so all around it's a bad idea.
Was about to say the same thing, glad others are mentioning this.
@@MidnightMarrow I've been an auto, jet engine mechanic and a metal machinist for 60 years. Yes, I'm 77 yrs. old. Been there , done that, got the "T" shirt as they say.
I'll bet bet a lot of subscribers don't know about mechanical things. They have other interests. All the best to ya'.
@@chieft3357 There was nothing you said that an 8yo wouldn't know. Dumping your 'credentials' is only more humorously pathetic.
I'm impressed the rotors held with that many holes in them
Right^ they would explode if he keeps it up
i think the performance drop when you went over 100 holes is from the rotor not having as much mass to soak up the heat and experiencing brake fade earlier
Exactly this
One of the more practical experiments to date
I really enjoyed this video, it answered several of my "what if I just..." questions. The engineers have obviously discovered that there's a point where cross drilling and retaining available braking friction surface is maximized, as this experiment proves. I'm also fascinated by the chamfered slotted and cross drilled rotors. The slots allow pockets for the gasses to expand and evacuate without compromising the structural integrity of the rotor disc. Science around this is very interesting, thanks Garage 54!
OMG I'm getting sick of seeing people say the same thing. The surface area has nothing to do with the braking ability. It's about the mechanical advantage (ie how far away from center the pad is) and the temperature of the pad itself. Every brake pad has an optimal operating temperature. That's why when they added holes, it got better up to a point until they added too many holes. It has nothing to do with surface area, OBVIOUSLY. Otherwise the initial holes wouldn't have improved the performance.
To make it crystal clear, the additional holes resulted in less rotor mass to absorb heat. Thus, with too many holes, the pad gets too hot and becomes less effective.
I had drilled, slotted, and vented rotors on my dually. They lasted over 200k miles and that’s with pulling and hauling as a dually truck was intended for. I didn’t replace them with the same thing. I got regular vented rotors and they wasn’t the cheapest either. But they lasted half as long. Same as the pads. About half the life as before
I had a set for almost 250k on a s10. Replaced them when I saw cracks starting to form.
Yeah mine was starting to wear threw to the center vents. Still stopped fine just made noise. Never warped or any issues.
Mine only lasted 20K, towing a lot. Never going to waste money on it again.
@@BBb-hs9ud YOU MUST BE GHEYLORD
Heat kills things
Nothing like driving with Swiss cheese rotors 😂😂😂. You guys are great for showing crazy things people think of doing.
Brakes are converters of car energy due to friction to heat. Better heat disipate, better are brakes, but the more holes, the smaller the temperature capacity and friction surface so brakes are less efficient. U need to balance friction temperature capicity and heat dicipate, to have the highest friction, highest heat dicipate and not loosing the temperature capicity( this parameter is responsible for multiple braking).
yeah its better if they added heatsink fins to the rear or cut into the rear to make some grooves
those stopping tests would have to be repeated like two or three times to see brake fading and if it doesn't crack near those holes, Ive seen dozens of cars especially going sporty or on a track with cracked rotors near those holes, never seen any with full ones, but my guess is they will cool down harder due to limited airflow and dust on them
You're talking to a bunch of Russians though. Science = out the (broken) window.
That was a good one! I had a feeling you'd hit the snow bank before the end of the video! I was hoping you'd do exactly as you did at the end and get multiple stops into the brakes.
This is a demonstration of unsprung weight and thermal mass.
Unsprung weight: weight of components below the suspension that rotate with the wheels (includes rims and tires). The lighter you make this, the more dramatic the results (each lbs is about equivalent to removing 10 lbs of weight anywhere else)
Thermal mass: the amount of mass on an object capable of resistance absorbing and dispersing heat through itself. Think radiators for CPU cooling. If you apply 100 watts of input to 100 grams of mass, it will be cooler overall than applying that same 100 watts to 90 grams of mass because there is less material to hold the heat.
I'm not 100% sure I was accurate, so if you're interested in these ideas I suggest you go research them yourself because sometimes you might find a secret interest, you never know.
Love the creativity, the ingenuity, and the the passion for Motorsport fun .. I really enjoy your channel !
The fact that you did all that work in the field is impressive.
My concerns would start going to the structural integrity of the rotors at some point. Yes, they are hardened, but they will eventually break. But it was a great endeavor.
Was thinking the same
Brake rotors are hardened?
Hardened brake rotors? Wait, it's a Lada.
It's important to note that the operating temperature of the brake pad is critical in how the brake pad performs. That is, with a normal brake pad that is designed for everyday driving, the brakes are expected to operate in a lower temperature band, and therefore will benefit from the rotor having less mass to shed heat more quickly. That's why it initially started stopping better.
For a race vehicle, when the brakes are expected to be operating regularly at much higher temperatures, those pads will NEED more heat to operate properly, and will therefore perform better with a rotor that absorbs more heat. In fact, under race conditions, having mass to absorb that heat is critical, so drilling lots of holes will only result in worse braking performance.
It's interesting to see this test, because they got to a point where they drilled so many holes that even stock brake pads eventually performed worse.
11:50 Counted 348 holes drilled.
How many drill bits they broke I wonder
🇧🇷 I really love these crazy tests you do 😁 the good thing is that it clears up a lot of people's doubts 😃
Lol it needs to be done in a "lab" situation to get real results, have them sit under load for xxx of time and have a stationary mounted thermal checker pointed on the same position and show the differences in the graphs like a dyno tune :D pretty fun all the same!
72 holes was the magic number.
Everybody is so wrong here. No top level racing series use drilled rotors (F1, WTCC, BTCC, LEMANS, etc). At most they have small J slots or just flat discs.
They don't want to lose any brake performance with less surface area and less rotor mass. Modern brake pads do not offgas like old pads used to.
It worked fine with the first 3 sets of holes. Because there was sufficient surface area for the pads to hold on too , more holes less surface area for the pads.
They should make a 'race car on a budget' with loads of stock lada parts to see what slightly improved stock parts can do to a cars performance
"They really look like meat grinding plates"
Well now we know where you gotta go next.
Tests have shown that cross drilled are not as effective as slotted. The gasses produced by the pads dont have anywhere to go. Also, it has less metal to soak up the temperature, thus brake fade will start sooner. This is from a brake manufacturer i used to deal with.
Being a motorcyclist the major benefit for us is improved wet wether breaking as the water gets stepped into the drillings. Wobbels the mad Aussie
The most surfaces you take off is the less surface the brake pad has press on hola from Mexico
My car (MK5 GTI) has non-ventilated cross driller rotors in the rear. The rear rotors are oversized enough, and being a front drive car, it doesn't need ventilated rotors, and you have to go into the high end aftermarket rotors to find ventilated rears. Tho to be fair as well, the stock rotors aren't drilled at all, but I have mid range aftermarket rotors intended for use on an Audi TT. (Zimmerman sport)
I've noticed that the projects you have taken on and the ideas you've tested in the past few Years has progressively gotten better. Keep up the good work, I love seeing your ridiculous ideas and I feel like I can clearly see how much more competent you've all gotten over the Years (that's not to say you were ever incompetent!)
I don't know what's more impressive, the braking results or the car still running during the testing!
I must say I never thought I would get this hooked
the montage at 2:00 goes unbelievably hard
Most roters I have seen have had a second rotor that had holes in the sides with some joining metal to make square holes on the sides. So you have two smooth surfaces for the break pads.
Enjoying your show here in the US with my son. Haven't laughed this much since we used to watch MYTHBUSTERS and they had a life sized dummy named TED: It was variously detonaTED, assassinaTED, exploDED, etc....from cannon to cars, and everything in between!! LOL! BTW, a friend told me how happily she "defrosted" her new car windshield with hot water; it worked for her and her dad was furious! Keep up the good work, gentlemen!!
By the end of the video I was more interested on the BRAND of "drill bit" they were using!!! 😂😂😂
The holes were drilled straight across the solid rotors, what if they were drilled at a slight angle to create a fan blade type of effect pulling cool air from inside the wheel arch, passing thru the brake rotor and being forçed towards the outside of the wheel...forçed air draft removes more heat
That would for sure crack the rotor
I love the cute drill setup 😂 a battary as stool small press drill ideel
i liked that too
Works up to one hole every half-pad width. Beyond that, you start losing too much surface area and heat soak capacity.
god i love these experiments
You need 3 at 5 test for promedy. And news brake pads for test whit new hols in disc.
Your new test car is a real beauty! Did you trade a screwdriver or a pair of sunglasses for it?
It's obvious to me that the ultimate brake rotor would be a transparent one. Garage 54 has repeatedly proven that transparent auto parts are superior in all respects to opaque auto parts.
Making a clear rotor should be much less difficult than making a clear engine block so you may as well just do it so we can all learn how much better they will work than conventional, old-school (boring) steel rotors.
I love these guys and this channel :)
The reason the stopping distance got shorter but the temperature went up is due to the law of conservation of energy. You are changing the forward motion into heat when you apply the brakes. So the faster you can change the motion to heat, the faster you stop.
enough holes helps in releasing the gases release between pads and rotors while braking and it makes the pads gripping the rotor better. helps in reducing the heat better while releasing the brake and cruise.
too much holes means less surface contact between pads and rotors, less material to grip.
Drilling brake disks aids cooling but reduces grip surface area the sweet spot can be calculated.
I thought the holes made them grip better by having holes to squeeze into
Like a texture on the surface same with slotted ones idk
@@chrissanders2562nah it's for cooling. They use them on race cars as they are breaking at high speeds and sharply as a regular disk would likely get damaged as ofcourse metal is weaker once it gets hot.
@@chrissanders2562 it allows gasses from the hot pads to escape, same as grooves, not needed in normal driving as the pads don't get hot enough to emit gasses, apparently the gasses get trapped behind the pads and reduce braking
Now I have a question, what if you drilled the holes out of 45° angle in either direction and maybe one with a 45° angle in both directions
I would like to know what the rotors weight is after this compared to stock
one note of confusion with the temperature is that for a lot of performance rotors, due to their lower mass, they will often get hotter on any single stop. but for a more prolonged track application, they are more able to shed the heat to the air due to their increased surface area, resulting in more consistent stopping power and making them harder to encounter brake fade
Because at the increased speeds and increased rotations (and rarely braking to a complete stop), you have the highest transfer rate of heat to the air, and it stays that way consistently through the raceway track.
Performance rotors will have more mass, not less. The goal isn't to shed heat faster, it's actually to hold heat in. That's what makes for more consistent stopping power. Performance brake pads need heat in order to work. Just look at an F1 car.
@@rars0n this is provably false, there's a reason high end performance rotors use aluminum centers to lower weight, because heavy anything in a performance application is bad, especially unsprang mass such as a brake rotor. and as for the F1 point, the only reason it needs to be above a certain temperature is because they use carbon-carbon brakes that need to be above about 300C to have a good coefficient of friction, and if you take a look at brake improvements after moving to carbon, it's all about minimizing the size of the radial holes in the rotor and maximize surface area for shedding the heat.
where do you think the energy for stopping a car goes when you brake? the rotor on it's own is not nearly massive enough to "hold the heat". The whole point of brakes is to convert kinetic energy to heat and then shed that head to the air moving over/through the rotors
@@renchesandsords Yeah, they use aluminum hats for less unsprung weight. You will only find such hats on much larger diameter rotors, because they're designed to hold more heat while also shedding some of the weight that would otherwise be wasted on a heavy steel rotor center.
"the only reason it needs to be above a certain temperature is because they use carbon-carbon brakes that need to be above about 300C"
Incorrect. Carbon ceramic refers to the rotors themselves. The pads are what determine the operating temperature of the brakes. Carbon ceramic rotors are used in race cars because they are stronger, last longer, and are lighter weight than steel discs.
"if you take a look at brake improvements after moving to carbon, it's all about minimizing the size of the radial holes in the rotor and maximize surface area for shedding the heat."
The surface area has nothing to do with it. Like I said, it's the mass. The braking system converts stopping power into heat, so if you maximize the mass, you maximize the amount of heat that the braking system can absorb.
"where do you think the energy for stopping a car goes when you brake?"
It goes into the rotor. Any brake engineer will tell you this.
"The whole point of brakes is to convert kinetic energy to heat and then shed that head to the air moving over/through the rotors"
So you agree with me. Great. But the rotor is constantly shedding heat when the car is not braking. It seems you have forgotten that the goal of a race car is to go fast. Therefore it won't always be stopping fast. Performance brake pads only work in a small window. F1 brake pads work in the SMALLEST of windows. So they have to retain heat in order to work. Why else would they design plugs to block off holes in the brake ducting on certain tracks? If the goal was to shed as much heat as possible, they would never use these.
Every brake pad in existence is designed to work better at a certain temperature, even OEM pads. They ALL work worse when cold, and cold is a relative term depending on the vehicle and its use. But there's no arguing with the fact that high performance braking systems are designed to operate at higher temperatures.
@@rars0n hmm, just tried a hypothetical, yeah you're right, the heat shed during the actual braking zone is not a particularly large component of brake cooling and it's more during the higher speed non-braking portion, but on the whole, I think being efficient about shedding that heat is what makes a braking system more capable for a race as it brings the rotor temps lower for each braking zone
proche 911, roughly 1500KG, and brake rotors about 10-12KG(front), assuming avg10KG b/w rear and front, that's 40KG of brakes to absorb heat, let's say approaching a turn, you go from 300km/h down to 100km/h, that's a delta of 56m/s in about 3.5s assuming a little over 1.5G braking deceleration, that means there's about 4.8MJ of kinetic energy to be either taken up or dispersed across the 4 rotors. if dispersion is a negligible part of braking, then assuming the rotors were starting at 20C, they would heat up to around 250C.
even assuming the rotors were at 250 the whole time and fast airflow over the surface, the energy shed would be well under 1MJ during the braking zone
The idea of cross drilled rotors is to allow gasses to flow out through the centre of the rotor. It won’t work on non vented or solid rotors as there is pad on either side of the hole. Cross drilled rotors get rid of gasses more efficiently than slotted rotors at the expense of structural integrity. You will find that drilled rotors get replaced frequently in motorsports as they will start to crack at the edge of the holes because of continual head cycles and mechanical stress.
Excellent video
should have only done 1 wheel at a time then you could compare sides equally, temperature wise and the better braked wheel would have pulled to one side
Great Test!
crosdrilling means not sinking the holes! they have to be sharp to prevent wedging the air between the disk and the pads, they lifting on air film when there are to many holes . you created a trustbearing like a ship propellor bearing. my motercycle has stainless disks with holes to prevent loss of breaking in rain. great job boring so many holes! keep on the good work I am enjoying it very much.
You guys are f'n ridiculous - i love it
As I understand it drilled brake rotors is to give better breaking when the disks gets wet with mud, as I understand it only something used off-road as it give no benefit in other situations.
Need to measure how much quickly it cools more precisely vs the og rotor. They tend to get hot but dissipate heat quicker so by the time you're at the next turn and getting down on them they've cooled quicker. They hold some heat for optimal performance but dissipates heat quicker to combat brake fade like you saw with the last few runs at high speed and lots of holes drilled
Holes are not for cooling. They are to eliminate brake fading. Gas between pad and rotor can escape through the holes
Very interesting demonstration of the law of diminishing returns
Should have left it a set time or driven back around without using the brakes and measured the temp again each time to see how much it cooled each time. With less material it’s going to heat up faster, but more surface area it’s going to cool faster too. Idea is that the brakes cool faster between uses on a track for instance. Also, cross drilled discs are more effecting on vented discs, as they are shaped to pull air through them as the wheel spins.
11:50 i counted the holes. you drilled 357 holes in there
wow
you made cooling channels for brake rotors xD quite clever
Solid!
Top KEK!
Peace be with you.
You're also removing metal and reducing the specific heat capacity of the rotor which is why its quicker to heat up.
I guess it reveals a lot on brake technology when u see the brake system on a motogp bike... it has no holes. The carbon bakes wont overheat so i guess there is no need to ventilate and therefore max contact with the disc for most stopping power.
More holes... = less contact area....hence longer stopping..
The rotors have a certain amount of holes before they get beyond the benefit of more power
That's not true actually.
If the contact area is smaller, the calipers will exert a greater pressure on the disks(since the surface area is smaller), so the breaking force will be the same.
@@jort93z ya. C.f. and all that
I love how you can hear the car crapping out as it approaches the braking zone.
What about an elastomeric mounted roll-cage within the car frame that moves forward, independently, after the initial collision.
This will remove much g-shock from the passengers.
6 in. of travel should be cool.
I wonder if BRIMBO got their start this way? Ether way, very COoL. Looks like a Lotta' fun. The last time I was this excited to see holes was on my last "3rd date" p.s. I didn't know about spraying black, mat paint prior to temp measuring. 500 points awarded to the team!! Cheers from the other side of Earth
Love you guys all the way from Mexico
More holes more efficient slowing via debris dispersal. The energy has to go somewhere that's why high heat and decrease of stopping performance at a certain point.
seems like a few holes shorten the stopping distance and cool the discs but too many and it makes the stopping distance greater
I wonder if they realise as brand new brake pads and rotor go through the initial wear in stage they actually begin to perform better.
Can you try brakes with Teflon plastic. Put petrol,gas in the oil to see how much more power it gets.
Wonder if this cross drilling brake rotors would be applicable for drum brakes?
@John MHGood suggestion on the drum brakes. 👈😁
Yo lo hice con discos macizos y lo que pasa es que hacían un ruido como de matraca, con el tiempo entendí que con la temperatura se dilataba el aire dentro de los orificios y ese era en ruido, como pequeñas explosiones, aunque parecía que se había rajado el rotor, y volví a ponerle rotores normales ya que tampoco se notaba una gran diferencia
10:17 POV: you're this man lunch and you're almost falling
Holes make higher surface area for heat dissipation. Grooved rotors are for debris clearance. Too many holes affects rotor life dramatically and strength is compromised.
At some point the lack of surface area doesn’t allow the vehicle to stop so you do need a good balance between surface area and ventilation. The cross drills slots allow brake dust and rotor material to be removed and fresh material to contact the rotor and note harder.
Shouldn't the friction between the pads and rotor should be the same regardless of surface area?
@@bennykakes5845 Think about what you just said lol
@@IvanOoze1990 Wdym? the formula for friction is F=uN. With u being the coefficient of friction and N being the normal force. Do you see area anywhere in that equation?
Less mass more surface area it will heat up and cool off faster you found the point of diminished returns when you removed too much friction surface
It actually doesnt reduce or increase friction if there is a linear coefficient of friction. Since the same pressure from the brake caliper is applied to the same friction material you actually end up with the same amount of friction. Its a weird thing.
Lots of materials dont have linear coefficients.
@@timothybayliss6680 if this is the case what caused the increased stopping distance
Gotta love all these P.O.S cars they use 😅
The reason it eventually fails stopping is because they keep remove surface area, you might think the rotor would work as usual but the pad actually touches as much as 80% less material.
I love when Vlad said I thought I said stop
The real benefit is in cooling off quickly while still moving. Coming to a complete stop negates the whole purpose. Also there is obviously a point of diminishing returns.
For science!
Less material, same work = obviously higher temperature. What about the holes in the discs? Thanks to this, they cool down faster before the next braking.
ooof lovely sills on that motor!!!!!🤣🤣🤣
Это был интересный эксперимент. Спасибо за предоставление результатов теста торможения. Мое заключение состоит в том, что некоторые отверстия могут помочь с краткосрочным охлаждением после тяжелого торможения. Но для достаточной производительности торможения необходима определенная площадь поверхности.
Omg. I can't believe this. It's still stopping sooner! 🤣👌
If I remember right the drilling is for more bite and stopping Force when was brake pedal pressure and when you slot rotors that is for cleaning debris from the brake pad and letting the gases escape
If there was any benefit of either, F1 would use it!
@@petkokrushev3840 nope F1 don't use them because their break rotors are spinning so fast that it releases the gases quick enough and if you know anything about F1 cars you would know that their brake pedal has to be pressed with just about all the strength of the driver when they are used their brakes are very hard to push in most of the F1 cars I can't speak for all but most of them stayed quite a bit of strength and I could be wrong but I'm pretty sure they're brake pads are made out of different materials than most of your passenger cars
and now try to make DIY slits on the Brake Rotors like the EBC or ATE Powerdiscs have 👌 this works a way better and you don't get cracks between the holes on the brake rotors like you get on drilled ones.....
At the end the metal is there to keep the holes in place
I counted exactly 342.
How i did it you ask?
Screenshot the rotor, Took it into paint, where i used a yellow marker and al old school Tally counter.
every hole i marked yellow i clicked the tally, clicking all holes tally's added up to exactly 342
That's why you put on harder brake pads with drilled discs to stop brake fade.
Less material means getting up to temperature much more rapidly as well
This is giving me major "license test in Gran Tourismo" vibes
The problem with cross drilled holes, is they cause horrible brake squeal. Slotted rotors, where lines are carved into the metal, are better.
Man does it ever warm up there?
This was maybe a little bit of fallacy. For holes to better cool the rotors, they would need to cool while driving, they can't cool the rotor down additionally if its stopped. How hot will they be when stopped depends on thermal capacity, which you lowered by removing material.
Try it with vented disc