Harnessing the Demon: Challenger Brake Pad Upgrade Options

Brake pads are engineered to produce friction. The job of the braking system is to convert kinetic energy to heat, which is responsible for slowing the vehicle down. Each time you press the brake pedal, the brake fluid will push out the pistons in the brake caliper. This, in turn, will press the brake pads against the brake disk so you can stop safely without much fuss or drama. 

When it comes to automotive brakes, there are two general types of friction: abrasive and adherent friction. Abrasive friction is produced when the friction material of the brake pad is in contact with the disc directly and the rubbing action between the two results in a break-down (at the molecular level) of both pad and rotor. In other words, an abrasive system wears both pad and rotor simultaneously. 

On the other hand, adherent friction is a phenomenon that occurs when the pad leaves a trace layer of material on the surface of the disc and then is rubbing against that. Thus, apart from the time it takes for the pad to heat up and develop a thin layer on the disc, the pad is never really contacting the metallic rotor surface directly. This causes the pads to wear at a faster rate without much wear on the rotor.

In the case of the Challenger, which sports ceramic pads as standard equipment, both abrasive and adherent friction is used. At lower temperatures, the braking action is caused primarily by abrasive friction. Once the pads are warm, however, adherent friction takes over. 

The brake pads and the brake disks are not entirely responsible for the stopping performance of a Dodge Challenger – the tires play an important role in braking action as well. Alas, the topic of having the right set of tires is best reserved for a separate discussion.

Brake pads are basically steel backing plates and friction material. The type of friction material will dictate how the brake pads perform in a variety of driving conditions. There are three basic types of friction materials for brake pads:

Organic (non-asbestos): Organic pads are producing using a compound of organic materials mixed with resin. The most common type of fillers utilized in organic-based non-asbestos brake pads are brass fillings, rubber, glass or fiberglass, Kevlar, or carbon compounds. While the exact formula will depend on the brand or manufacturer, organic brake pads will usually contain no more than 10 or 20 percent metal. 

Pros

• The organic-based materials are cheaper to obtain and produce
• Less brake dust
• High levels of friction with less heat
• Perfect for everyday driving and mild performance applications

Cons

• Wears out quicker and will need to be replaced more often
• Only functions well in a limited range of temperatures (does not respond well to extreme heat)
• Spongy brake pedal feel (organic pads are softer and more compressible)

Metallic: Metallic brake pads will usually have around 30 to 70 percent metallic content. This includes composite alloys, steel, copper, and iron fillings. Due to the aggressive metal-based formula, metallic brake pads have a harder lining. This enables it to last longer than organic brake pads. The metal fillings also enables the brake pads to quickly dissipate heat, which makes them ideal for racing or high-performance driving.

Pros

• Can withstand higher temperatures to prevent fade
• Better stopping ability
• Ideal for racing and high-performance driving

Cons

• Higher cost
• Can be noisier or squeakier than organic pads
• Produces more brake dust
• Can be harsh on the rotors/disks

Ceramic: Brake pads with ceramic friction materials are more expensive than organic and metallic pads. It is crafted from a delicate mixture of copper and ceramic fibrous materials. Ceramic-based brake pads offer superior heat dissipation while reducing wear on the rotors.

Pros

• Virtually zero noise
• Softer ceramic lining reduces harmonic vibrations for increased refinement
• Produces less brake dust
• Operates well in a wider range of driving conditions and temperatures

Cons

• Most expensive option
• Not intended for racing applications

It’s the same story with high performances tires which require heat to deliver high levels of grip and traction. Racing brake pads (usually the metallic variety) need higher amounts of heat to produce the necessary friction to stop the vehicle. Once they are at temperature, they can aggressively bite the rotor and bring things to a stop. It’s the complete opposite when a racing pad is cold. Braking performance will be seriously deteriorated (possibly non-existent) as the friction material is too cold to actually produce any friction. The operating temperature for racing pads certainly varies by manufacturer, but you’ll almost always find it to be in the range of 600 F – 1400 F. Unless you are thrashing your Challenger around at the track, obtaining and sustaining these temperatures will be borderline impossible, thus making an all-out race pad a poor choice.

A standard (read: street pad) brake lining will need significantly less heat than a racing hand but can still deliver exceptional braking power. A performance street pad will likely be designed to work within a range of 100 F to 600 F – thus making it good for regular and spirited driving.

Properly bedding a pair of new brake pads is paramount in order to achieve lasting and reliable performance. A brake pad set that does not bed properly can have disproportionate braking between sides, excessive fade, and increased pad or rotor wear. The actual process of breaking-in or bedding-in a new set of brake pads is specific to the manufacturer and thus their instructions should be followed. Below, however, is a general guideline of how most brake pads are broken in (this should only be performed in an area with little or no traffic). As a general rule, you should avoid intense stopping maneuvers and applying abrupt brake pedal pressure for the first 100 miles if the brake pads are new. 

Step 1: Drive your muscle car at 45 mph and apply medium to easy braking until the vehicle comes to a full stop. Repeat this step for three to four times and allow the brakes to cool. 

Step 2: Next, drive the vehicle at 60 mph and apply medium to hard braking pressure until the vehicle slows down to 15 mph. Repeat this for six to eight times while allowing the brakes to cool down between each run.

Step 3: At this point, the brake pads should be properly bedded in. 

If braking performance is of utmost importance, the upgrades should not be delegated to the brake pads alone. While the stock vented discs are enough for street applications, upgrading to a better set of cross-drilled and slotted rotors will ensure stronger and more reliable stopping power in high-performance driving.

The brake calipers should also be considered when upgrading to larger brake discs. Upgrading the calipers will increase the sweeping area of the brake pads to provide shorter stopping distances.

One of the most popular brake upgrades (next to the brake pads) are the brake lines. The factory rubber lines are a durable and low-cost solution. However, the rubber lines tend to expand under demanding conditions and will result in a spongy or squishy brake pedal feel. Since braided brake lines will resist expansion much better than rubber, this means better braking response and a firmer brake pedal feel under high braking forces.