Brake System Upgrades

I'd have to say that upgrading your brakes should be one of the first mods to your car, if not the first one. If you're a hard-core tinkerer when it comes to your engine, the "go" will easily exceed the "whoa" when you least expect it--brake systems are prob'ly one of the easiest upgrades out there. I'm not an advocate of big-ass (not to mention insanely expensive) big-brake conversions from Brembo, Wilwood, AP, etc. on cars that see a helluva lot more street use than track use. Most of these systems were designed for severe race duty. Some even include brake pads that require heat before they start gripping the way they were designed to--can you imagine being one block from your house, with brake pads that haven't had enough heat scrubbed in, yet, when some semi-trailer pulls in front of you? By the time the pads have heated up for even a moderate stop, your car will be underneath the truck! Sure, you can do it for "show-off factor" for your friends, but you can easily screw up the balance of the car. Keep it simple and there will be fewer problems that pop up in the long run.

Brakes are one of the most oft-understood components in a car. Physics actually explains in mathematical terms how the car's velocity is decreased by braking forces. Basically, the car's momentum is scrubbed off by converting some or all of it into heat. The brake pads are a friction source and transmit this heat by conduction (physical contact) primarily to the rotors (which acts as a fancy heat sink) and allowed to scrub off by way of convection (transfer of thermal energy through the air). In extreme circumstances (i.e. stock brake components in a high speed road race), this thermal energy can be conducted to the brake fluid which will boil off (fluid fade) if the hot rotor just keeps accumulating the heat. Using this knowledge, the best way of improving upon the brake system is by increasing the rotors' ability to bleed off thermal energy and utilizing brake pads w/ more stable compounds that can withstand such harsh conditions. How do we do that? Read on...

So, what do I suggest for brake upgrades? Thought you'd never ask...
1. High Quality Brake Fluid
   What it does: It has to put up with extremely high temperatures at times, all the while keeping the same fluidic properties over a large temperature range--brake fluid helps conduct "brake pedal feel" to the driver. If the fluid goes past its useful range, funny things start happening to the brakes--they start to fade and lose their feeling. You may find that, for the same stopping force, you have to push the brake pedal deeper and deeper until it inevitably hits the floor. Some autocross cars need their brake systems flushed with new brake fluid every few runs for this very reason.
   Tips: Run Motul. If not, I've found that the Valvoline synthetic fluid works well and doesn't boil off as quickly.
2. Alternate Bleeding and Complete Flush every 6 months
   What it does: Keeps the fluid fresh. I realize that bleeding and flushing your brake system takes a long time, especially if you're by yourself, but at least you don't have to do it often. If the brake fluid in the reservoir is dark or black (have you no shame?!!), that's a sign that you need to completely replace the fluid. Bleed each caliper till the new, lighter-colored fluid comes out.
3. Stainless Steel Braided Brake Lines
   What they do: Replace the rubber lines that will swell because of old age. The pressure that you input at the brake pedal isn't fully utilized by the calipers because some of the brake fluid expands the rubber lines first. When the "swell" reaches its maximum, only then will the brake pedal be fully "connected" to the pistons and brake pads--this is the infamous "spongy brake pedal" people talk about. With new SS braided lines, your pedal will be much more firm.
   Tips: Make sure that they're DOT-approved and come from a reputable company.
4. Application-Specific Brake Pads
   What they do: Provide stronger bite, endurance, and grip during more "spirited" driving.
   Car manufacturers have good intentions when they select the OEM brake pads, but most cars are still designed to please the masses and not the driving enthusiast like you and me. Of course, we expect more out of our brakes, so naturally, we have to chuck the OEM brakes--keep 'em as some ultra-modern sculpture or paperweight if you like!
   Tips: I've recently (5/19/02) switched to the Porterfield R-4S compound brake pad up front. For now, I'm running OEM rears due to slight rear wheel lockup issues. The Porterfields don't squeal (YMMV), and don't fade (believe me, I've tried!) while driving as fast as anyone with a sense of self-preservation would drive on the Pacific Coast Highway. They do require 1-2 stops to warm up from a dead cold. But, after that, they will have a tighter grip on the rotors than old people with their Pepto Bismol. What's even better is that they work better and better as you get more and more heat into 'em. Plus, the pedal effort on my car has dramatically decreased for any given stopping force. They do throw out a bit more dust than other pads, but this is to be expected for a performance application.
5. Slotted Rotors (Optional)
   What they do: Keep the pads' swept area "clean" so that the initial bite and contact are better. As such, this creates more heat. Some people in the racing industry believe that the slots allow some heated gases to escape and help prevent pad fade. Slotted rotors won't crack like cross-drilled rotors because the grooves are only a few millimeters deep and don't pass through the entire rotor.
   "Yeah, but all I see are cross-drilled rotors on real race cars!" Yeah, yeah, yeah... But, they can afford to replace their cracked rotors after every venue! There are some advocates of cross-drilled rotors that say, "If you don't abuse 'em, they'll last just as long..." But, isn't that missing the point of upgrading your rotors? If you get the urge to drive 'em into the ground, you want 'em to take the punishment and ask for more, right?
   Tips: If you do decide to go to slotted rotors, stay away f/ Power Stop products--I've heard nothing but bad things about them. Also, avoid slotted rotors that are "home-made" in machine shops. If possible, go w/ the tried and proven brands like KVR, Brembo, Wilwood, Alcon, or Lockheed. If all else fails, stick w/ OEM rotors and get 'em cryo-treated. You'll notice that the CART rotor shown above is slotted, not crossdrilled.
6. Crossdrilled Rotors (Optional)
   What they do: The holes allow heated gases and thermal energy an "escape route." In theory, this will allow you to run pads w/ a higher coefficient of friction (race pads) w/ better endurance characteristics (no fade). Many race cars use crossdrilled rotors for this very reason. These rotors supposedly run up to 30°F cooler than solid-faced vented rotors. In practice, though, these rotors in a street application (you poseurs know who you are!) tend to crack due to extreme thermal variations (hot rotors getting doused w/ a puddle of water which evaporates and forces the heat to escape at a faster rate) than the metallurgy allows. Some advocates of crossdrilled rotors say that they last "if you aren't 'hard' on them..." Isn't that missing the point of buying performance rotors?
   Tips: Unless your production-based car spends 75% or more of its time on a track, I wouldn't waste your money on them. Many nationally competitive SCCA SOLO II autox racers I've talked w/ don't believe crossdrilled rotors have any great advantages in autox settings; the only one is decreased mass for less rotational inertia, but braking performance always outweighs that notion.