Brake Pads

This is a broad subject to cover because there are so many variables to consider that go along with your driving style. You should not have OEM-style brake pads on a dedicated race car or rally car, and you should absolutely not have a race-compound track pad on a car you use as a daily driver.  

OKAY, BUT WHY?

Let's explain in Layman's race car terms the big difference between the two. OEM or OEM-like brake pads have been designed to stop your vehicle throughout all weather conditions and temperatures. Meaning that they will have a solid braking "bite" when you leave your driveway at 6 am on a 20-degree December morning and your car stops normally when you approach the first stop sign in your neighborhood. You don't even think about it, your car is acting normal, and it's another normal daily commute. OEM and street pads are also quiet, they don't squeal, and they produce a minimum amount of brake dust so you don't get your fancy wheels dirty. 

Racing brake pads serve a main purpose and utility, and shouldn't be used on the streets. Racing brake pads are made using harder compounds designed to sustain and withstand extreme temperatures as they are constantly working to stop your race car at your track. Depending on the track layout, depending on how fast and powerful your vehicle is, racing brake pads will endure continuous and increasing heat to avoid the chances of brake fade to also endure endless stopping sessions. If you look at photos of race cars while stopping, you will notice the brake rotors glowing red hot. In these conditions, your OEM brake pads would literally melt, making you lose all braking pressure, and you wouldn't be able to stop. But the reason why racing brake pads are not good for the street is that they need to be warmed up before they start grabbing the rotor. Many times, a "bedding" process is required for your racing brake pads. This is where you find a safe area where you can accelerate to 60 mph or so and stop your vehicle as fast as you can. You do this until you start building heat and wearing off the top surface of your brake pads, while also building friction with your rotors. The bedding process would offer some brake pad "bite" if you were in a race event where you did not do a warm-up lap for your tires and brakes and just got sling-shotted out on the track. Now going back to the beginning, if you installed race brake pads on your daily driver and left your driveway on a cold December morning, and made your way down the street while approaching the first stop sign while applying your brakes, you would more than likely drive through the stopping area because there is no heat buildup in the pads. It would be like trying to stop with cold bricks as brake pads in your calipers. Maybe not this extreme, but you would at least be applying a lot of brake pedal pressure until you've got a little heat into the pad. 

ARE THERE HYBRIDS?

There sure is. And this will be the best option for those of you with a daily-driven Subaru WRX, STI, or any fast car such as a Mitsubishi Evo where you have any mod that makes your car faster such as a proper tune with an intake, or full exhaust, and beyond. If you participate in a weekend track event such as an HPDE event at your local track, a half-mile event at your local airstrip, and at the drag strip if you make decent trap speeds, you will need a brake pad stronger than an OEM or OEM-like compound to avoid the chances of brake fade, and we're going to talk about that in a minute. A good hybrid brake pad will offer a good "bite" meaning they will grab well in colder conditions, but they will sustain higher temperatures during those high-performance driving conditions. The main drawback is that they will produce more brake dust and more noise during braking. And many of you know already what it's like participating in these events in OEM-like pads and how dangerous it can be. If you're approaching the first turn from a long straight at your track, or if you are trapping 140+ MPH at your drag strip and you hit the brakes and you feel as if your vehicle isn't stopping as it should, and if you are overwhelmed with the distinct pungent smell of burning pads, that is the reaction of cooked OEM pads. This is where you really need to pay attention. 

WHAT IS BRAKE FADE?

There are many examples. The short answer is that your braking components are overheated, you can't stop your car, and you have no choice but to crash, or in the best scenario run off track and hope the sand pits or the grass slows you down enough. Here is the first example of brake fade. Let's say that you're preparing for your first track day. You go to your local parts store and buy whatever brake pads they have in stock because you want to make sure you're safe and that your vehicle's maintenance is all caught up. You get them installed and head to the track the next day and everything seems fine, but the smell of the brakes increases and then the braking performance all of a sudden gets worse and worse and you either have enough friction left to pull off safely, or you keep going and you can't stop at all. This is a form of friction fade. What causes this is when your brake pads get so hot that they cook a film of pad residue that glazes over your brake rotors, and then you lose friction between the pad and rotor altogether. And this is why it is never a good idea to track with basic brake pads that don't have a high heat tolerance, and why a racing brake pad is required for dedicated race cars, and a decent street/track pad is the best idea for those of you who like to enjoy weekend track events.

Another example of brake fade is when your brake fluid gets too hot, and actually boils inside your braking system. If you have upgraded rotors and calipers with an appropriate brake pad compound for the track, these components will endure the heat. But if you have standard brake fluid or old fluid, you are at risk of boiling the fluid during a prolonged track session, or even a short track session on a mid-summer day. When your brake fluid boils, it creates air pockets inside the hydraulic system, then you lose your brake pressure. With old brake fluid, it can absorb moisture that creates vapor in the hydraulic system which can cause the same effect. You need to use a braking fluid with a higher boiling point to avoid this from happening. And often times while at the track, drivers can be seen bleeding their brakes in between sessions to release any built-in air in the system, and after every track session when your car is at home and in the garage, it is always wise to bleed the brakes again when they have had time to cool and to be prepared for the next track event, or just for safety measures when driving to work. 

Note that hot brake fluid can cause vehicles with rubber OEM brake lines to expand under pressure, but stainless steel brake lines will help with this issue. We will cover the topic later on in this discussion. 

Another example of brake fade is if you have an older vehicle or a modern classic that still has older brake pads. While at a track event, these older styles of brake pads can generate gases and residue, which can also glaze over the brake rotors to prevent friction. This is one of the reasons why cross-drilled or slotted rotors became standard-issued components on some older manufacturers' vehicles. The drilled holes or slots will wipe the face of the brake pad clean while repelling hot gases through the rotor vanes to reduce heat while providing an optimal friction surface between the pad, and the rotor. With newer brake pad technology, you can find a great brake pad replacement that will outperform the stopping power and performance when compared to older brake pads.

NOTE:

Make sure whenever you're replacing your brake pads, take the time to inspect your BRAKE ROTORS. Worn brake rotors can and will accelerate brake pad wear as worn or damaged rotors can have grooves on the surface. Also note that whenever you get new brake rotors, it is always a good idea to get new brake pads as worn or uneven brake pads can damage your new rotors. 

Additionally, when replacing your pads or rotors, you will usually have to depressurize and widen the pistons on your calipers to make enough clearance to get your new pads over your rotors. This is a good opportunity to bleed your brakes and install fresh BRAKE FLUID. This is especially crucial if you have a race car or if you track your daily driver on the weekends as your brakes can get hot enough to make your fluid boil which can create moisture in your fluid. Also dirty brake fluid from lack of brake fluid changes or bleeding can inhibit your overall braking performance. Dirty brake fluid will eventually create buildup in your lines and hydraulic system.

Speaking of your BRAKE LINES, this would also be a great opportunity to upgrade to stainless steel brake lines. If you have a 2002 WRX or a 2003 Evo, or if you have a brand new Subaru stainless steel brake lines won't expand under pressure. This provides a direct response from the brake pedal to the caliper, and they can sustain more heat when compared to OEM brake lines. A great upgrade that will also improve your overall braking performance.