Braking Business

Taking care of the most important part of your car

Mike Petralia Jul 22, 2003 0 Comment(s)

The brakes are the most important performance component on your car! Now that we've got that off our chests and hopefully grabbed your attention, perhaps an explanation is in order. Think about it for a moment. Obviously without brakes, cars wouldn't be much fun to drive. You've probably never thought of them as a performance part, because we all typically refer to performance as things that can make a car go faster, not slower. But if you've ever pushed a car to the limits on a curvy highway, and your brakes pushed back, then you're aware of what we're talking about. Any of the old Chevrolets can benefit from better brakes up until the Fourth-Gen cars, for which there are still improvements that can be made, but at a costly price. And unless your car is intended for the drag strip only, with no street driving in between, than a set of big four-wheel discs can make your daily commute a blast!

While there are many replacement four-wheel disc brake systems available today, several companies have addressed the issue of BIGGER brakes. True, four-wheel disc brakes were even available way back when, but those brake packages left a lot to be desired. If you were to hunt down a factory replacement four-wheel disc kit for your early Chevrolet, then you'd be getting small rotors and heavy calipers. What the aftermarket guys have done is incorporate the best the world has to offer by using light-weight aluminum calipers, made popular by the European car market, and super-sized rotors to give braking abilities beyond what GM ever achieved.

A BIGGER BRAKE
When it comes to brake rotors, bigger is definitely better. But we're not just talking about diameter here, although that's usually the first dimension to increase. Thicker rotors offer more heat absorption capabilities because creating heat is what a brake system does most. Thicker rotors are able to absorb more heat and dissipate it into the atmosphere better than thin rotors. A difference in thickness of just 0.100-inch can make a big difference in braking performance, especially after several hard stops.

Larger diameter rotors offer more braking leverage to improve stopping power. They accomplish this by moving the caliper further away from the spindle centerline. It's the same effect as using a longer breaker bar to bust a tough nut loose. But, of course, bigger rotors need bigger wheels to fit inside. And the large 13-inch discs this Camaro had in front, combined with the new 12-inchers we added out back required 17-inch diameter wheels with a lot of offset (6-inches on both) for clearance.

PRESSURE
Brake systems multiply the pressure you put on the pedal usually by a factor of at least 4:1 and as high as 6:1. The brake pedal ratio is determined by dividing the distance from the center of the pedal pivot to the center of the pedal pad in a straight line; see "Pedal Ratio" illustration. (Do not calculate the curve in the pedal). Manual brakes require a higher ratio than power-assist brakes, but most brake pedals are drilled for both. If you're switching from power-assist to manual brakes for a more responsive "feel" at the pedal, then you'll need to switch your pedal ratio by moving the master cylinder pushrod pin. This may also require installation of an adjustable pushrod, available from Master Power. Master cylinder bore size also has an effect on the pressure your calipers see. In this case, it's best to purchase a master cylinder from the same company you bought you brakes from to be sure it's properly matched.

Whether you're harder on brakes than a NASCAR Champion, or drive like a little old lady--whatever driving style--you will benefit from bigger brakes.

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Big Baer 12-inch rear discs can make a powerful statement both visually and when you stomp on the pedal.

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We replaced the original power-assist master cylinder with a manual cylinder from Baer to improve pedal "feel" to the driver. We threaded special Earl's aluminum -3AN fittings into the master cylinder and attached Russell -3AN stainless-braided Teflon hoses. The Baer proportioning valve was mounted on the firewall and new Classic Tube stainless hard lines were plumbed.

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This stainless steel -3AN "T" fitting from Earl's Performance features a tab on the end for mounting. We had to drill the tab out to 5/16 and add a 1/2-inch tall spacer under it, but it made a nice junction block on the front frame under the master cylinder. The left line comes from the front fitting on the master cylinder. The braided line to its right goes to the driver's side caliper and we flared the custom-bent Classic Tube stainless hard line (bottom) with a special 37-degree Imperial Eastman flaring tool to fit the -3AN tube nut and sleeve to send fluid to the passenger side caliper.

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The Classic Tube hard line then goes into a Baer Brakes adapter fitting for the caliper's flex line, which is a Baer Brakes stainless braided Teflon hose. Master Power provided the new bracket and replacement spring clip we used to secure the connection to the frame.

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This photo shows the new Classic Tube pre-bent stainless steel brake line we installed in the stock location behind the front K-member on this '70 Camaro.

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When installing large rotors out back more caliper clearance may have to be created. The driver's side on the Second-Gen Camaro presents the biggest problem because of its forward caliper placement, but a few whacks with a hammer on the inner fender seam gives the necessary clearance.

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The Classic Tube hard lines are shipped pre-bent to fit your application.

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Each tube has strategic "shipping bends" that are easily straightened out before installation.

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Here's a close-up of the front-to-rear brake line laid out next the old line removed from the car. Each bend was pretty close to perfect right out of the box. A little hand tweaking was needed in a few spots, but the pre-bent line was much easier to install than trying to custom bend a line ourselves.

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When ordering your pre-bent lines, make sure to tell the manufacturer what you will be doing. We ordered our front line without the factory master cylinder "pigtail" which added extra inches to the line instead.

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When customizing a brake system like this, you'll need fittings and lines. Most brake companies and AN hose manufacturers offer a wide selection of lines and fittings.

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The large assortment of stock fittings is from Master Power, while the braided Teflon hoses and special AN fittings shown here are from Earl's.

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This Camaro already had big 13-inch Baer brakes in front, so we just needed to upgrade the rears. The 12-bolt in this car had been modified with Ford 9-inch ends welded on to eliminate the C-clips. That meant we had to order Ford caliper brackets and 12-inch rotors with the correct offset to match. The caliper brackets are adjustable to several positions to provide clearance.

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Ever since we got them, we keep finding more uses for these Matco 12-pt Torque Adapter wrenches. They can get behind things and into tight spaces to allow full application of torque using a long-handle 1/2-drive ratchet.

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We found it easiest to bolt the rotor in place using a few lug nuts when installing the calipers.

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We had to cut and custom double-flare the rear hard line to fit the Baer Proportioning valve.

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This Master Power hydraulic flaring tool made quick and easy work of that.

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There's two distinct types of 90-degree AN fittings on the market today. Tube style and low-clearance nut style.

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Both lines work equally well, and your application can dictate which style lines you choose.

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Pedal ratio is determined by dividing A by B and the A dimension is from the center of the pivot to the center of the pedal pad in a straight line. (Note: most pedals in production models are curved, but do not calculate the curve.)

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