The Importance of Rotor Design: Understanding Venting, Drilling, and Slotting

In the world of high-performance braking, the design of the rotor is crucial for achieving optimal stopping power and durability. One of the key factors to consider is ventilation, which refers to the strategic placement of small holes or air channels in the rotor to facilitate heat evacuation. This feature can be achieved through drilling, where tiny holes are drilled into the rotor to allow gases and debris to escape, or slotting, where a slotted design is used to improve airflow around the brake pad.

Drilling Rotors: A Less Popular Option

One of the ways to ventilate a rotor is by drilling small holes into it. This involves using specialized tools to create tiny air channels that help to evacuate heat and debris from the rotor. The idea behind this design is that as the braking compound breaks down, it creates a layer of gas that prevents the pad from touching the rotor due to the pressure difference between them. By drilling these small holes, the gas can travel out more easily, carrying any debris or moisture with it. However, there are some disadvantages to using drilled rotors. For one, they reduce the surface area of the rotor, which can actually decrease its ability to reject heat. Additionally, the holes created by drilling can become stress points during wide temperature fluctuations, leading to cracking and potentially causing the rotor to fail.

The Limited Advantages of Drilled Rotors

While drilled rotors may seem like a good idea, they have some significant limitations. In racing applications, they are often used for aesthetic purposes rather than actual performance benefits. The drilling process can be time-consuming and labor-intensive, which makes them less desirable for high-performance brake systems. Moreover, the reduced surface area of the rotor can lead to increased pad wear, as there is less area for the braking compound to dissipate heat.

Slotting Rotors: A Popular Alternative

Another ventilation method used in high-performance braking is slotting. This involves creating a slotted design on the rotor's surface, which allows air to flow through and help cool the brake pads. Slotting can provide several benefits, including improved airflow around the pad and a reduced risk of brake fade. Unlike drilling, slotting does not reduce the surface area of the rotor, making it a more desirable option for high-performance applications.

The Advantages of Slotting

One of the main advantages of using slotted rotors is that they can provide improved braking performance without sacrificing durability. The airflow created by the slots helps to dissipate heat from the brake pads, reducing the risk of brake fade and improving overall stopping power. Additionally, slotting can be used in conjunction with other cooling methods, such as brake ducts or fans, to further enhance cooling performance.

Limitations of Slotting

While slotted rotors have several advantages, there are some limitations to consider. For one, they may not provide the same level of airflow as drilled rotors, which can lead to reduced braking performance in certain conditions. Additionally, slotting can create additional stress points on the rotor surface, particularly if the slots become damaged or worn out over time.

The Best Option: Vented Rotors

In many cases, vented rotors are the best option for high-performance brake systems. By creating small holes or air channels in the rotor, these brakes can provide improved ventilation and cooling, leading to increased braking performance and durability. Vented rotors can be designed with either a plain exterior surface or a slotted design, allowing drivers to choose the level of airflow they need.

Venting vs. Drilling: Which is Better?

When it comes to choosing between vented and drilled rotors, there are some key differences to consider. Vented rotors offer improved ventilation and cooling through their strategically placed holes, while drilled rotors provide a similar benefit but with the added advantage of being aesthetically pleasing. However, drilled rotors have some significant limitations, including reduced surface area and increased stress points due to temperature fluctuations.

Conclusion

The design of the rotor is a critical factor in achieving optimal braking performance and durability. By understanding the different ventilation methods available, drivers can make informed decisions about which brake system to use. Vented rotors are often the best option for high-performance applications, offering improved cooling and airflow without sacrificing durability. While drilled rotors may offer some advantages, their limitations make them less desirable in many cases.

"WEBVTTKind: captionsLanguage: enhello everyone and welcome in this video we're going to be talking about performance rotors drilled vented and slotted and why you may or may not want each of these individual features and a shout out to carpark kings for sending the brake rotors to use in this video you can check out the video description for relevant links diving right in starting with vented disc brakes this is very commonly used on the front brakes for cars and so basically what the purpose of this is is to allow for better cooling so you've got your two plates and then there's an air gap between them to help evacuate that heat and sometimes you'll actually notice they've got curved vanes and so this kind of turns it into a small pump and so it basically pumps the air out and helps to evacuate that heat and allow for better cooling and longer lasting rotors that don't fade as you get into higher temperatures okay moving on to drilled rotors and this is where you simply just drill through it so you've got some little air holes in it and this is something that used to be a little bit more useful and these days it isn't really anymore but basically you have bonding agents in the pad that breaks down at high heat especially true for older pads uh they use different materials modern ones aren't quite as bad uh and so this these bonding agents as they break down it creates this layer of gas and so that layer of gas prevents your pad from touching the rotor because of that pressure in between so these holes allow for that gas to travel out as well as any particulate debris from the the pads themselves or water if you get any water or steam on it helps that evacuate through these holes now the bonding agents uh these days are much better so you don't really have that gas gap in there and so there's some there's some disadvantages of this as well so you may think oh it's got all these air holes that's going to be better for cooling well the other thing you need to think about is you have a reduced surface area and you have less mass to reject heat into so it's not necessarily a beneficial trade-off also these holes become stress points during wide range heat cycles and this can lead to cracking so because you know if you're going really fast into a corner you slam on the brakes and then you accelerate up to a high speed again these are going to go through a very uh large temperature change and so these holes are going to be cooler than the areas around them and so you're going to have these large temperature differentials throughout the break and what that's going to do is start to cause the rotor to fail and you'll have cracks in there because of the stresses associated with it so honestly in racing these really aren't used um you know they're they're just not that their advantages don't pay off for their disadvantages uh because they can fail and have cracking due to the stresses in the holes so not ideal for racing too weak and also as i mentioned previously the new pad compounds have improved and so you don't really have this gas layer between the pad and the rotor like you used to so why do you see drilled rotors on like amg cars on ferraris on high-end uh street based cars well because it looks awesome and it does look awesome but honestly that's pretty much it and you know the other thing is they can be built strong enough for street applications so it's not necessarily an advantage to use them but they look cool and they can be built strong enough to last if you're going to do it yourself i wouldn't recommend using drilled but nonetheless yeah they're used on on performance cars because it makes them look pretty awesome moving on to slotted and these serve basically the same purpose as drilled you're giving that debris somewhere to evacuate or those gases and it also can help wipe that pad clean through each rotation and it can also provide an additional biting surface that leading edge and that unfortunately can lead of course to increased pad wear but these are actually used in racing unlike drilled and so it can add some benefits so in professional racing applications what will you see we'll pretty much always see vented you may see slotted and you'll rarely if ever see drilled as it has the stress disadvantage i mentioned earlier now they'll also do other things to improve braking so you can change the diameter of the rotor make it larger but sometimes you're restricted by your wheel size so you can make it thicker like for example in rally racing they're restricted to 15 inch wheels so that really limits their brake rotor size so they make them wider and you got to make sure that those are well vented because you've got a large mass within that and then also brake ducts for cooling so if you can get air flow to the brakes that's you know significantly better uh way to cool them than some of the other methods out there and just as some examples uh the subaru rally car that i checked out that one used uh slotted rotors and then the nissan lmp1 car that i checked out that one just used plain vented rotors and so what is the best option well pretty much vented is is a good bet to go with and then either plane on the exterior or slotted and you know you can probably stay away from drilled unless you just think it looks really cool and you don't really care about the fact that it's going to probably fail before these other two options so thank you for watching and if you have any questions or comments feel free to leave them belowhello everyone and welcome in this video we're going to be talking about performance rotors drilled vented and slotted and why you may or may not want each of these individual features and a shout out to carpark kings for sending the brake rotors to use in this video you can check out the video description for relevant links diving right in starting with vented disc brakes this is very commonly used on the front brakes for cars and so basically what the purpose of this is is to allow for better cooling so you've got your two plates and then there's an air gap between them to help evacuate that heat and sometimes you'll actually notice they've got curved vanes and so this kind of turns it into a small pump and so it basically pumps the air out and helps to evacuate that heat and allow for better cooling and longer lasting rotors that don't fade as you get into higher temperatures okay moving on to drilled rotors and this is where you simply just drill through it so you've got some little air holes in it and this is something that used to be a little bit more useful and these days it isn't really anymore but basically you have bonding agents in the pad that breaks down at high heat especially true for older pads uh they use different materials modern ones aren't quite as bad uh and so this these bonding agents as they break down it creates this layer of gas and so that layer of gas prevents your pad from touching the rotor because of that pressure in between so these holes allow for that gas to travel out as well as any particulate debris from the the pads themselves or water if you get any water or steam on it helps that evacuate through these holes now the bonding agents uh these days are much better so you don't really have that gas gap in there and so there's some there's some disadvantages of this as well so you may think oh it's got all these air holes that's going to be better for cooling well the other thing you need to think about is you have a reduced surface area and you have less mass to reject heat into so it's not necessarily a beneficial trade-off also these holes become stress points during wide range heat cycles and this can lead to cracking so because you know if you're going really fast into a corner you slam on the brakes and then you accelerate up to a high speed again these are going to go through a very uh large temperature change and so these holes are going to be cooler than the areas around them and so you're going to have these large temperature differentials throughout the break and what that's going to do is start to cause the rotor to fail and you'll have cracks in there because of the stresses associated with it so honestly in racing these really aren't used um you know they're they're just not that their advantages don't pay off for their disadvantages uh because they can fail and have cracking due to the stresses in the holes so not ideal for racing too weak and also as i mentioned previously the new pad compounds have improved and so you don't really have this gas layer between the pad and the rotor like you used to so why do you see drilled rotors on like amg cars on ferraris on high-end uh street based cars well because it looks awesome and it does look awesome but honestly that's pretty much it and you know the other thing is they can be built strong enough for street applications so it's not necessarily an advantage to use them but they look cool and they can be built strong enough to last if you're going to do it yourself i wouldn't recommend using drilled but nonetheless yeah they're used on on performance cars because it makes them look pretty awesome moving on to slotted and these serve basically the same purpose as drilled you're giving that debris somewhere to evacuate or those gases and it also can help wipe that pad clean through each rotation and it can also provide an additional biting surface that leading edge and that unfortunately can lead of course to increased pad wear but these are actually used in racing unlike drilled and so it can add some benefits so in professional racing applications what will you see we'll pretty much always see vented you may see slotted and you'll rarely if ever see drilled as it has the stress disadvantage i mentioned earlier now they'll also do other things to improve braking so you can change the diameter of the rotor make it larger but sometimes you're restricted by your wheel size so you can make it thicker like for example in rally racing they're restricted to 15 inch wheels so that really limits their brake rotor size so they make them wider and you got to make sure that those are well vented because you've got a large mass within that and then also brake ducts for cooling so if you can get air flow to the brakes that's you know significantly better uh way to cool them than some of the other methods out there and just as some examples uh the subaru rally car that i checked out that one used uh slotted rotors and then the nissan lmp1 car that i checked out that one just used plain vented rotors and so what is the best option well pretty much vented is is a good bet to go with and then either plane on the exterior or slotted and you know you can probably stay away from drilled unless you just think it looks really cool and you don't really care about the fact that it's going to probably fail before these other two options so thank you for watching and if you have any questions or comments feel free to leave them below\n"