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I decided to put this FAQ together to help people decide how about going upgrading brakes as well as helping people fimilar how to buy brakes to fit for their needs. Not everyone need 16" rotors front and rear and still complain about how they can't stop better than stock.
Q: How does one stop the fastest/shortest?
A: It really starts with the tires. Brakes are one thing, but the main concern is about how the tires grip the road to stop.
Q: Tires? What? I thought we were talking about brakes?
A: Tires are the only thing that keeps the car in contact with the road, you are relying on 4 little patches of rubber to keep a 3000+ lbs car on the road. So yes, tires do make a difference. For example, if both cars had super awesome brakes, but one car had rubber soft slick tires while the other car had just bare rims, which one would stop faster? It's obvious that the tire will get into better grip (friction) with the road than the bare rim. It's hard for bare metal to dig into the concrete. If you dont believe me on the matter that tires dont make a difference, ask race car drivers why they have to use racing slicks.
Q: Ok, so tires are upgraded, now what?
A: Hopefully, the tires you chose helps you narrow down what kind of brakes you should look into. I have broken down the three common tires you will find and 3 kinds of brake upgrades you can get along with the car.
Tire A, Daily driving: This is the kind of tire that would be on your car most of the year and winter driving is possible since it could very well be an all-season tire.
Tire B, Spirited driving, Autocrossing for Street Touring: This is the kind of tire that is more dedicated for street use in the summer or possibly an autocross street touring race setup. The tire is fairly soft and the potential for harder braking is possible (also less chance for the ABS to come on).
Tire C, Race and Race-practice driving: This is where your tire is barely DOT-approved and street legal, the tires barely last more than 5,000 to 10,000 miles conservatively for street driving or only 100 miles for race use. These types of tires are sticky.
Brake Upgrade A, conservative driving: This is the setup you are looking for that you expect to keep on your car for a while unless the brake pads run low. The key things to upgrade are better brake fluid, better brake pads. The driving habit is mild and delicate braking, long drags, and low speed stops (think slow daily driving). Look for a brake pad that has a high coeffiecent of friction (for that quick bite) and low operating temperature (so that winter or cold brakes will still work).
Brake Upgrade B, spirited driving: This setup is something that might need some higher performance pads, better rotors to help prevent brake failure or poor performance. Things to look for are stainless steel brake lines, better brake fluid, slotted/cross-drilled rotors, larger or higher operating temperature brake pads.
Brake Upgrade C, hard driving: This setup is to help you get the most out of your brakes without worrying about overheating/overworking your brakes. This setup is usually for racing use only since the brakes (and tires) need to warm up first before they work properly. Things to look for are racing brake fluid, bigger rotors with slots or crossing/drilling, racing brake pads, stainless steel lines, bigger calipers that can handle larger brake pads. All these parts help you keep the brakes work in the higher braking temperature ranges. Overheated brakes are just as bad as having no brakes at all.
Q: Are slotted and cross-drilled rotors needed?
A: Slots are useful to a point when you are looking for a way to prevent glazing of the brake pads. Glazing of the pads happen when you overheat the brake pads (either too hard on the brakes and not big enough of a rotor to dissapate the heat fast enough thus makes the pad material harden and it starts to lose its frictional properties. Cross Drilled really has no real use now as brake technology has advanced.. it does have an appealing look to them, but as for today, you dont need them as they serve next to nil on purpose. Specifically on the Legacy (GT or 2.5i) the brakes are fairly well using just the stock rotors. The weight of the rotors (mass) is pretty heavy.. more mass also helps in heat capacity, so the more mass you have for the rotors, the more repeative braking that you can do. Big Brake Kits do benefit from this very reason, but a few other brake tests has shown that the thickness of the plates and the overall thickness of the rotor proved to be more of a useful design than just the overall diameter of the rotor [Motor Trend did the study about 2 to 3 years ago I believe]. Blank rotors are fine and does the job, especially for a daily driver that doesnt need that heat capacity.
Q: So what kind of brake pads out there?
A: There are a lot of brake pads out there, things to take consider are the three main attributes that usually 2 attributes are offered in a braking pad:
-Dusting/Noise (how much they make your bling rims dirty)
-Temperature (the range of temperature of which the pad works)
-Friction (how well the pad has the initial bite and feel to the rotor)
It's very hard to find a brake pad that can be awesome in all 3 attributes. Street pads will have great low noise/dusting, good friction bite, and typical low temperature range. Performance pads will have good friction, good temperature range, and typical medium dusting. Race Pads have great temperature range, good friction, and lousy dusting (very dirty).
Q: What temperature is right for me?
A: If you are looking for daily driving and expect to drive through a winter season, look for a brake pad that can operate in low or freezing temperatures. If you are looking for autocross and very light track days, look for above freezing to 800 F temperature ranges. Very rare that a daily driven or street driven car hit temperatures of 1000 F unless you are that crazy to hold the brakes down at near full force while driving at 40 mph for 15 mins. Racing brake pads start near the 150F to 1500F+ range (so somehow the driver needs to warm up the brakes before actually using them).
Q: How do I pick a good brake fluid?
A: The thing is to look for the HIGHEST WET BOILING POINT (as brake fluids do soak up moisture in the air and causing the fluid to fail and feel mushy). Change your brake fluid at least once a year or every 15,000 miles for the best pedal feel. ATE Super Blue fluid is probably the best "bang for the buck" at $15/bottle for a full flush. Always use a fresh bottle, dont use a bottle that has been open for more than a month as it has probably soaked up dirt and other moisture in the air that would make the fluid ineffective.
Q: What about stainless steel lines?
A: Usually designed for better pedal feel for less pedal brake travel and less flex in the lines. It's an upgrade that is really up to the owner as stock lines offer enough PSI of fluid for the caliper to clamp with enough force. Unless you are upgrading your master cylinder and larger calipers, upgraded stainless steel brake lines with higher PSI rating is not neccessary
Q: What about big brake kits?
A: Big brake kits are used to make use of the tires' grip potential and dissapate heat faster. It's not neccessary for a street car to run with larger brakes unless you run the Autobahn or something and have the tires run them. Also, check the brake pads that the brake kits come with. There's no sense in getting bigger brakes (more weight) if the brake pads are lousy "performance" pads that can overheat and glaze.
If there are any other questions, I'll will answer them on a case-by-case basis from here on out.
Last edited by Xenonk; 10-29-2006 at 06:20 AM..