Upgrading Factory Brakes

Why Upgrade?

If the time has come for you to R&R the brakes on your car, stop and think. How much can you improve the performance of the original setup? Will substituting high-performance aftermarket parts for the factory-replacement pieces make a big difference?

Conversely, for all the cash you can throw at performance parts, it makes sense to keep the OEM hardware if it's up to the task. Think about it -- the manufacturer spent a lot of money developing your car, so there's got to be a few good pieces on it. In many cases, particularly the current crop of domestic and import sports/pony cars, there's a good set of brakes on the car, hobbled by organic pads and flimsy low-grade metal rotors. How much better are a set of aftermarket rotors and pads? Consider that the use of higher-quality metal means longer rotor life and even wear, and that rotor drilling and slotting allows the brake pad to breathe better. Upgraded pads will use different friction materials that bite the rotor surface more effectively.

The difference can be seen with hard numbers. We established a baseline with factory disc brakes at all four corners. Our '96 Mazda Miata test car was chosen for its balance, drivability and lack of ABS brakes (which could confound the test circumstances). Wanting to use the best-available materials for the Miata, we dug about online and through catalogs, researching what options we could. The Miata is quite popular with autocrossers and road-racers for it's eminently nimble chassis, but some of the brake parts available were too assertive for realistic street use. Thorough checking did reveal several suppliers of slotted and/or drilled rotors, and several of semi-metal pads. Moss Motors, Ryane Motorsports, Dealer Alternative, Brembo, EBC Brakes, Power Slot and Stillen all had popular factory-dimension upgrade pads and rotors that fit our specified parameters. We have arranged the test stages to reflect use of the upgraded semi-metal pads with factory rotors, followed by the same upgrade pads paired with slotted rotors, as people are more likely to swap just the pads. No modifications were made to the factory calipers.

What about the factory brake lines? There's a section of rubber tubing that connects the metal feed lines to the caliper in the wheel well. This rubber ages and becomes soft, allowing it to expand and contract (in circumference) under pressure and defeat your braking efforts. What if you replace those rubber lines with lines sheathed in braided stainless steel? Finding DOT-legal stainless steel braided lines was not too hard, usually available from the same distributor as the other brake hardware. We installed the DOT-legal braided steel brake lines at the onset of the testing to ensure consistent performance with all hardware tested. The greatest feature of steel braided brake lines is that consistency. Reduction of line-flex improves brake control by keeping pedal feel consistent and linear.

Testing Brakes

The test arrangement was simple: at a specific point on the tarmac our driver would stop the Miata from 60 mph. This was done three times with less than two minutes between each run. The stopping distance was measured each time by Stalker radar gear and averaged for the posted overall stopping result. This was repeated for each brake change, thus the subsequent numbers.

Note: We took the added initiative to conduct our brake testing in a real-world environment. Instead of visiting our usual test track, we performed the 60-0 testing on a private-access road, to allow us to consider real-world braking circumstances. We had slightly uneven pavement, an expansion joint and a relatively narrow lane to work within. No huge expanses of perfect concrete with lots of run-out room for us, just like you probably won't have when YOU need to brake in an emergency.

The baseline testing was an understandably underwhelming affair, using factory brake pads and brake rotors all around. The braided-steel brake lines sent to us by Moss Motors were installed prior to this first series of tests, so we could be sure of consistent results throughout the testing. Try a set of braided lines and you will agree -- the brake pedal has never been that firm. We found our average 60-0 mph stopping distance to be 187.98 feet. This is a greater distance than the standards set by professional drivers, but remember the test environment -- just like that which you'd find on the street, everyday. This is what you'd do. The factory pads and rotors performed admirably and didn't heat up excessively during our test run, but they transmitted limited feel when pushed hard and locked up the tires too easily.

In the second group of tests, things became entertaining. The Hawk pads supplied by Moss Motors were quick to bite, and produced much more pedal reaction when braking at the limits of adhesion. Modulation of braking pressure was also easier -- we could skirt the edge of lock-up, hovering just at the limit with greater regularity. The average stopping distance from 60-0 mph benefited as much as pedal-touch, netting us an average of 167.11 feet. Any competent driver can find better braking control with these Hawk Ferro-Carbon pucks, even if stuck using the factory rotors. Everyday cruisers will learn how a high-performance brake pad feels instead of the factory replacement, because the difference is obvious.

Our third stage of testing involved the high-performance Hawk Ferro-Carbon pads putting the squeeze to new slotted rotors from Moss Motors. The concept behind slotted rotors is simple -- provide an escape route for pad heat, gasses and residue. As the brake pads clamp onto the rotor, the subsequent friction creates hot gasses and heat between pad and rotor face. The slotting allows the gas and heat to evacuate more quickly, prolonging pad and rotor life. It also averts the cushion-effect caused by that heat and gas between pad and rotor. Not surprising, the slotted Moss Motors rotors and hi-po Hawk pads combined to deliver the quickest stops of our testing day. The 60 to 0 stops in our Mazda Miata test car averaged out to 157.94 feet. That's about 30 feet shorter than with stock equipment, and 10 feet shorter than with just upgraded pads.

Notes: You don't want to install a new set of pads on grooved and/or heavily worn rotors. That rotor will almost instantly damage the pads. Whether using a high-performance pad or stock, be sure your rotors are in good shape. If a rotor happens to be lightly grooved or used, most brake shops can resurface and true it (cutting the rotor face smooth on a brake lathe) for you. Of course, you don't need to worry about that if you're going to high-performance rotors too, as we recommend. Also, always do brake work in sets, front or back. If you're going to replace the passenger-side front pads and rotor, do the driver-front too. Get it?

The Facts

What did this brake upgrade teach us? We checked the pricing with one large Miata-performance supplier, and found that an extra $85 front and $80 rear for performance rotors, and an extra $35 front and $37.45 rear for performance pads can shave 30 feet off your 60-0 mph braking distance. In more general terms, the improvements to be had by installing high-performance bolt-on brake parts are readily apparent, even while reusing factory components like the calipers. We also learned that braided stainless-steel brake lines are a smart addition whether for performance or reliability, no matter what the application. You could spend about $250 bucks (including brake cleaner, rags, lube and tax, not counting the braided lines -- they go for $139.95) more than it would cost to buy basic factory replacement parts, and net a dramatic increase in braking performance and feel. That's a cheap performance upgrade.

Resources

brembo.com, dlralt.com, ebc-brakes.com, goodridge-usa.com, miatamania.com, powerslot.com, ryanemotorsports.com, stillen.com

Braided stainless steel brake lines. No more flex in the lines' circumference equals better pedal feel. Used by road racers for years, recently popular with the import/compact set, always worth every penny.

Built from better metal, aftermarket rotors can also be milled with grooves to improve pad breathing and the longevity of pad and rotor. There's also a slight shaving effect, which keeps the pad fresh (less chance of glazing).

Surely the easiest part of this brake upgrade to install, and probably the most effective buck for buck, upgraded pads stop quicker than factory replacement pads. Better yet, with upgraded rotors, they cut 30 feet off the 60-0 distance.

We did this project ourselves. Brake work is a great excuse for swearing like a sailor. We're finishing up the braided lines in back. Don't forget to bleed the air out of the entire system when you are finished.

Rotor, pads and lines, can be installed in less than an hour per corner, and netted a 30-foot average shorter braking distance.

Hard braking is a component of high performance driving. You should learn how your vehicle will react -- try it in a safe place. New brake pads need to be "bedded-in" (see manufacturer's instructions) before hard usage.

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