MJ23FE
01-12-2011, 06:08 PM
I find it hard to believe that you will be able to drive them on the street without ever heating them up. If you had a controlled place to scrub the rotors, then fine. Just doesn't seem realistic to me, I'd imagine you end up having a slightly hard time getting them totally cleared of old pad transfer. I read the article and could see how this would work, given the right situation though.
But he talks about starting with a clean slate, and i don't think he's going to argue that machine rotors aren't a clean slate. For a daily driver, that would seem to me to be the quickest way to get up and running with new pads without having to 'take it easy on the street' for a week. machined rotors, bed them in, and good to go.
I'm not being a dick, but in this particular situation, reading > j00.
http://www.essexparts.com/learning-center/cat/brake-pads/post/swapping_pads
My Daily Driven Brake Lathe
If you read my piece on choosing brake pads (http://www.essexparts.com/learning-center/cat/brake-pads/post/choose-brake-pads), you know that most race or track pads are very abrasive when driven cold. In other words, rather than transferring to the rotor face when cold, they primarily generate friction by scraping the rotor face. We're going to use that trait to our advantage, and scrape the old pad material off of our disc faces. We'll do so by performing a series of stops, without ever allowing the race pad to get hot enough to transfer to the rotor. Some compounds are obviously more abrasive than others, but generally speaking, most race compounds with a high coefficient of friction will work for this procedure. I've always used Hawk's Blue compound, which is a safe bet at a fairly affordable price, and comes in a wide range of applications. When going to the track, I usually keep a set on hand in my toolbox in case I need to clean up my rotors.
If you think back to my bed-in procedure in Know Brakes Episode 1 (http://www.essexparts.com/learning-center/cat/brake-rotors/post/Bed-in), you'll remember that the street pads I was using didn't start transferring to the rotors until they had a substantial amount of heat in them. With race pads, that temperature point is even higher. That makes it easier to quickly and safely get your rotors cleaned up and ready for a pad swap. You can do some fairly aggressive braking without ever getting them to the point of material transfer. So in this case, the procedure is actually the opposite of what you're trying to achieve with a bed-in. In a bed-in, you're performing a series of stops and trying to get the pads hot enough to transfer to the rotor face. During the pad-swap procedure, you're doing a series of stops while purposefully trying to keep your brakes as cool as possible. That means, you don't block off your brake ducts, and you may need to let the brakes cool a bit between stops, rather than just hammering them relentlessly one stop after the next.
The easiest way to clean up your rotors with race pads is to simply drive them around as your daily driver for a few days. Let's go back to our earlier street-to-track example. You did your bed-in with your Hawk HPS street pads. You have a track day coming up in a week. You plan on using Ferodo DS1.11 for that event. The easiest way to prep your rotors prior to bedding in your DS1.11's is to simply swap in the DS1.11's the weekend before the event and drive them around on the street. In normal daily driving, you'll never get the race pads hot enough to begin transferring onto the rotors. During that time they'll be operating in an abrasive manner, scraping the HPS material off of your discs. By the time your event weekend rolls around, you should be back down to bare, shiny metal on your discs. Sure they won't be quite as clean as if you were using brand new rotors, but you should be able to get just about all of the old pad material off of the rotors, providing the perfect canvas for laying down a layer of race compound through a proper bed-in.
Easy enough, right? Well, there is a downside to this solution. A common characteristic of semi-metallic race pads is that they often have a decided lack of cold bite. That means when your wife takes your Viper to buy a gallon of milk and makes a panic stop, she may not get the results she was expecting! Therefore, if you decide to go this route, please be extremely careful. Leave yourself some extra stopping distance, particularly on the first few stops when the race pads are completely cold. The other option would be to use sintered racing pads, which typically have great cold bite.
I had instant bite without any hesitation before stopping IMMEDIATELY after installing the RC5+ pads. I did not have the delay associated with swapping in brand new rotors. You might find it hard to believe. Well there's nothing hard about reading what I just wrote. It happened. Believe it. These are sintered pads, "which typically have great cold bite."
I'll take photos of my rotors tomorrow so that you can see what they look like after about 3.5 days of driving. A pretty big difference compared to what they looked like in my install photos above. 100% conservative street driving. I have not tried to test these yet, or even put heat into them for that matter.
Next week, I'll be performing my bed in procedure and will report back my results.
-Jalal
But he talks about starting with a clean slate, and i don't think he's going to argue that machine rotors aren't a clean slate. For a daily driver, that would seem to me to be the quickest way to get up and running with new pads without having to 'take it easy on the street' for a week. machined rotors, bed them in, and good to go.
I'm not being a dick, but in this particular situation, reading > j00.
http://www.essexparts.com/learning-center/cat/brake-pads/post/swapping_pads
My Daily Driven Brake Lathe
If you read my piece on choosing brake pads (http://www.essexparts.com/learning-center/cat/brake-pads/post/choose-brake-pads), you know that most race or track pads are very abrasive when driven cold. In other words, rather than transferring to the rotor face when cold, they primarily generate friction by scraping the rotor face. We're going to use that trait to our advantage, and scrape the old pad material off of our disc faces. We'll do so by performing a series of stops, without ever allowing the race pad to get hot enough to transfer to the rotor. Some compounds are obviously more abrasive than others, but generally speaking, most race compounds with a high coefficient of friction will work for this procedure. I've always used Hawk's Blue compound, which is a safe bet at a fairly affordable price, and comes in a wide range of applications. When going to the track, I usually keep a set on hand in my toolbox in case I need to clean up my rotors.
If you think back to my bed-in procedure in Know Brakes Episode 1 (http://www.essexparts.com/learning-center/cat/brake-rotors/post/Bed-in), you'll remember that the street pads I was using didn't start transferring to the rotors until they had a substantial amount of heat in them. With race pads, that temperature point is even higher. That makes it easier to quickly and safely get your rotors cleaned up and ready for a pad swap. You can do some fairly aggressive braking without ever getting them to the point of material transfer. So in this case, the procedure is actually the opposite of what you're trying to achieve with a bed-in. In a bed-in, you're performing a series of stops and trying to get the pads hot enough to transfer to the rotor face. During the pad-swap procedure, you're doing a series of stops while purposefully trying to keep your brakes as cool as possible. That means, you don't block off your brake ducts, and you may need to let the brakes cool a bit between stops, rather than just hammering them relentlessly one stop after the next.
The easiest way to clean up your rotors with race pads is to simply drive them around as your daily driver for a few days. Let's go back to our earlier street-to-track example. You did your bed-in with your Hawk HPS street pads. You have a track day coming up in a week. You plan on using Ferodo DS1.11 for that event. The easiest way to prep your rotors prior to bedding in your DS1.11's is to simply swap in the DS1.11's the weekend before the event and drive them around on the street. In normal daily driving, you'll never get the race pads hot enough to begin transferring onto the rotors. During that time they'll be operating in an abrasive manner, scraping the HPS material off of your discs. By the time your event weekend rolls around, you should be back down to bare, shiny metal on your discs. Sure they won't be quite as clean as if you were using brand new rotors, but you should be able to get just about all of the old pad material off of the rotors, providing the perfect canvas for laying down a layer of race compound through a proper bed-in.
Easy enough, right? Well, there is a downside to this solution. A common characteristic of semi-metallic race pads is that they often have a decided lack of cold bite. That means when your wife takes your Viper to buy a gallon of milk and makes a panic stop, she may not get the results she was expecting! Therefore, if you decide to go this route, please be extremely careful. Leave yourself some extra stopping distance, particularly on the first few stops when the race pads are completely cold. The other option would be to use sintered racing pads, which typically have great cold bite.
I had instant bite without any hesitation before stopping IMMEDIATELY after installing the RC5+ pads. I did not have the delay associated with swapping in brand new rotors. You might find it hard to believe. Well there's nothing hard about reading what I just wrote. It happened. Believe it. These are sintered pads, "which typically have great cold bite."
I'll take photos of my rotors tomorrow so that you can see what they look like after about 3.5 days of driving. A pretty big difference compared to what they looked like in my install photos above. 100% conservative street driving. I have not tried to test these yet, or even put heat into them for that matter.
Next week, I'll be performing my bed in procedure and will report back my results.
-Jalal