5.0 Mustang & Super FordsHow To Wheels Tires
SN-95 Ford Mustang Brakes - Sharpening Our Claws
We Upgrade Our Track-Car Braking System With The Latest From Baer Brake Systems
Horse Sense: With a Baer Track system on the front and a Touring system on the rear, our dual-purpose, open-track project car seems o have both bases covered. Actually, despite the racing and street-oriented names, the Track/Touring combination is perfectly matched mechanically, and it's the most popular Mustang seller at Baer.
In many ways, the toughest part of running a street/track Mustang is the brakes. The range of brake use-from shunting around on the street to gorilla rage on the track-is extreme. While the powertrain has computer controls to help bridge this span, and the tires and wheels are changed between the street and track, the poor brake rotors simply have to endure. Of all the systems on the car, the brakes do the most work in the shortest amount of time.
For one thing, our open-track car is positively porcine-a heavyweight with air conditioning, insulation, sound system, back seat, rollbar, the works. It has a fabulous suspension, so it really handles the corners and carries plenty of speed onto the straights. Its Nitto track tires provide great grip, further enhancing speed. The 3.73 gears get the 250 rear-wheel horsepower applied and digging. All said, if there ever was a car that liked to beat on the brakes, this is the one.
So we were quick to take up Baer Braking Systems on its offer to update our existing 12-inch PBR-based Baer system. Installed years ago, back when the company was Baer Racing, our brakes have returned yeoman service with nearly no attention. Short of a new set of brake pads occasionally, they've been hauling down this car since 1996. Lately, with the addition of racing pads, they've even been hanging in there lap after lap on the track (OK, we threw a set of front rotors in recently). Truly, we've had nothing to complain about.
But, of course, we could always do a little better, and with Baer eager to show its latest gear, we were off to Phoenix for an always-fun visit with the performance-afflicted at Baer. While Baer's offerings for Mustangs are extensive, they can be roughly divided into two major groups: PBR- and Alcon-based systems. We're going to leave the high-dollar, multi-piston Alcon brakes for another article o we can concentrate on the more likely object of your attention, the PBR-based gear.
PBR is an Australian company-a giant brake manufacturer supplying some of the best performance cars in the world. The Corvette, for example, has been using PBR brakes for two generations. So you can be assured that fitting a Baer kit built around the PBR caliper gives you a true high-performance street brake with proper weather and dust sealing, as well as the backing of numerous options when it comes to fitting pads.
Baer packages its familiar PBR-based systems for the front of the Mustang as Serious Street, Sport, and Track (we're ignoring the Grand Touring, GTP-HD, and GTP offerings that have no bolt-on Mustang application). The Serious Street system uses a 12-inch rotor that is 0.810 inch thick, along with the early style, finned, sand-cast PBR caliper. No logos or lettering are featured on the sand-cast caliper, which is available only in its natural as-cast aluminum finish and color.
The Sport system also uses a 12-inch rotor, but at 1.10 inches thick, it is nearly 0.3 inch thicker. The Sport also utilizes the upgraded pressure-cast PBR caliper. It has a smoother finish on the outside edge, not to mention the Baer Claw logo and "Baer" lettering. Polishing and several colors are optional with these calipers too. More importantly, the pressure-cast caliper more closely approaches the braking holy grail of ultimate caliper stiffness. Baer says the pressure-cast caliper's more rigid structure gives a hair more pedal feel and offers significantly longer fatigue life. That is, the sand-cast caliper can relax after years of service, leading to a bit of flexibility in the pedal. That's not a worry with the newer pressure-cast caliper.
Baer says the main cause of older calipers relaxing is drivers holding the brakes on while the brakes are hot and the car is stationary.
Stepping up to the Track system gives an extra inch of rotor diameter. As with the Sport system, the Track rotor is directionally vented. That means the vanes inside the rotor are curved to form left and right rotors. Besides improving the cooling some, the curved vanes provide more warpage resistance because they are spread a greater distance across the rotor's face.
Additionally, Baer offers rotor upgrades for such kits as the Serious Street, Sport, and Track that use one-piece rotors. The upgrades are to two-piece rotors, which use an aluminum centersection and an iron working surface. This is in deference to a rotor's bi-polar personality, where the more mass, the better for working with the huge amount of heat involved, and the less mass, the better for keeping total car and unsprung weight low. By building the centersection out of aluminum, weight is saved, but not at the expense of braking power or fade resistance.
In the Mustang Track kit's case, the two-piece rotors save 2.5 pounds per side, or 5 pounds of car weight (Baer has SS/Drag brakes that save 18 pounds over the stockers if straightline is your thing). The fasteners joining the two parts are NAS stainless units with mechanical locks, all of which are reusable. Furthermore, the detailing of the rotor shape is actually a little better than with the one-piece design, and there is some extra thickness in the "cheeks." It's a minor point, perhaps, but the larger concept is there is no loss of structural integrity in the two-piece rotor.
Offered under the Eradispeed name, Baer's two-piece rotors are $250 for the front pair. Those rotors can be slotted (or drilled, if you want) and zinc-washed for another $120. When we upgraded our brakes, Baer was offering the two-piece rotor upgrade with slots and zinc wash for a flat $250-the regular price for the rotors alone. That was a special price offering, so check with Baer or your Baer dealer to see if the deal still stands.
What we already had on our track car was, appropriately enough, a Track system. Installed well before the days of the pressure-cast caliper, Baer wanted to step us up to the new caliper, along with two piece rotors. It was an easy bolt-on job that we're detailing in the photos.
At the rear of our track car, the story is rather simple. The car has long had the Touring system from Baer, which includes the PBR caliper (with parking brake) and Baer 12-inch rotor. There is a Touring+ option from Baer that is the same system but with a larger 13.25-inch rear rotor. On a track car such as ours, the extra rotor diameter would actually help some because the chassis is so well balanced thanks to the torque-arm suspension from Maximum Motorsports. We actually use our rear brakes. However, the Panhard rod bracket from Maximum is large and close enough to the Baer brake that the 12-inch rotor is all we could fit-the 13.25-inch rotor was tried but hit the bracket-so Baer simply stepped us up to the latest one-piece, slotted, rear rotor in our 12-inch size.
Naturally, new pads were fitted all around. In our case, where we constantly shuttle between street and track, choosing the right combination of pads (and rotors), is something that can involve plenty of bench racing. At this writing there is no pad-and-rotor combination that completely spans the street-to-track gulf. The only worthy advice is to have two sets of pads and rotors-one for street, the other for track. Even our largesse doesn't stretch that far, however, so Baer installed Performance Friction 93-compound pads in our car. These are track pads, but ones Baer has found dedicated enthusiasts can tolerate on the street.
Since the installation, we've had no track opportunity to put our newly upgraded brakes to the hard test. But on the street, we can say the upgraded system has great pedal feel-maybe a bit better than with the old calipers-and the 93-compound brakes are definitely harder than our old street-only pads, but only just so. They definitely grip better with a little heat in them, which becomes evident down long freeway off-ramps and the like. These pads warm up in stop-and-go traffic, of course, but they will cool down between the odd corner requiring braking during casual secondary-road action. They'll make the occasional grunt, groan, or squeal, too, but hardly with every brake application. Considering their gung-ho track ability, they make remarkably civilized street pads.
We're definitely excited at the idea of taking them on track, where we know the 93's Indy-car-based compound will do great. In the meantime, we're enjoying our snazzy new binders mainly around town. With their good looks and our open wheels, that's not such a bad thing either.
Drilled, Slotted, and Washed
Three rotor options are popular when buying Baer systems: cross-drilling, slotting, and zinc washing.
Cross-drilling-the fishnet stocking of the three-is the series of small holes in the rotor's face. They stem from road racing, where they were widely used from the mid '80s into the '90s. The idea is to allow some of the gas produced by hot brake pads to escape the pad-to-rotor contact area. Venting this gas is a great idea, because when it is trapped under the pad, it forms an air bearing of sorts-exactly what you don't want a brake to do.
The trouble is, the holes seem to breed cracks, and their multiple sharp edges constantly swinging by the brake pad act like a cheese grater. The resulting small slices of pad material do mean fresh, unglazed pad is likely always at hand, but it's at the price of more rapid pad wear. This isn't so bad when racing, but it can be a true financial pain on the street.
The alternative is slotting. With much less area than cross-drilling, slotting still vents the pads and channels away worn brake pad material, but without the penalty of rapid pad wear. Slots don't start cracks either. As a result, slots are a bonafide performance option while cross-drilling is just for looks anymore.
Zinc washing is a protective anticorrosion/antioxidation bath for the rotors. It doesn't last forever, but it definitely slows down unsightly rusting of the center "hat" section for several years. This is especially true if you live outside the Rust Belt.
Baer offers these three rotor options as a zinc wash only ($70); a slot only ($90); a slot and zinc wash ($120); and a slot, zinc wash, and cross-drill ($120). The latter is the most popular choice.
Hang around a brake specialist these days and you're risking disc envy. Just yesterday a 12-inch brake was sporty and a 13-incher something special, but it's not quite so anymore. Thanks to the proliferation of gargantuan trucks and sport utility vehicles in street use along with corresponding, locomotive-sized, 20-inch wheels, "big" brakes these days measure 14 or 15 inches across the rotors.
For those playing the game strictly for bragging rights, the best we can tell you is to buy a truck so you can have the biggest of everything. For those looking for great braking from their Mustangs, rest assured a 13-inch brake that fits inside a 17-inch wheel still does the job with eye-popping efficiency. For example, Baer's Track kit fits inside 17-inch wheels. If you're going up to huge wheels, well, Baer has the rotors to fill them, but you'll want to measure the wheel and brake mock-up to make sure everything clears. To make the job easier, Baer keeps templates on its Web site (www.baer.com). These can be downloaded and transferred to stiff paper or light cardboard to use as a gauge when scoping out a new wheel and brake combination.
Baer asked us to remind everyone to use a torque wrench on their wheels. The bad guys here are overzealous air guns and their owners who crank down on one lug nut, then move to the next one. Baer says tightening one lug nut to its full torque, then moving to the one aside it can increase the torque on the first stud by 70 percent. That will warp the brake disc, and may even tweak the wheel-bearing bore. It's not good for the wheel either.
Such distortion is mainly an import-car problem, and it isn't prevalent with husky Mustang parts, but the danger is there. Use a torque wrench and a star pattern when tightening lug nuts. As for what torque to use, Baer prefers approximately 70 lb-ft, while Maximum Motorsports uses 90 lb-ft. All fine, says Baer, as long as the torque is evenly applied with a torque wrench in a star pattern.