You’re driving down a dark country road on a cool, summer night, enjoying the sound of your turbo spooling as you power out of the corner. Suddenly, a deer jumps out in the middle of the road. You bury your foot in the brake pedal as the ABS pulses. What’s the ending of the story you may ask? That answer depends on how good your brakes are.
The brakes on your Audi are one of the most important safety features that you rely on daily. However, with a basic A4 tipping the scales at about 3600 lbs, the stock brakes are not terribly efficient at scrubbing off speed time after time. In the same vein of the Suspension 101 article, this will cover some of the basics of upgraded brake hardware, although it will focus on the front brakes for now. It’s appropriate to start with the main parts of a braking system on an Audi:
Brake Caliper
The brake caliper is the assembly that houses the brake pads and the pistons. When pressure is applied to the brake pedal, the pistons squeeze the pad against the rotor to slow the car.
Caliper Carrier
The carrier holds the caliper in position. This is an important piece if you’re upgrading the size of the rotors.
Brake Rotor
The rotor is the steel disc that rotates within the caliper. It spins with the wheel and is slowed by the pad.
Brake Pads
The pads sit inside the caliper and slows the rotor when pressure is applied. There can be several different brake compounds, and most OEM brake pads have wear sensors to let you know when the pad life is getting low.
Brake Lines
The brake lines carry fluid to the caliper and expand when there is pressure in the system from depressing the brake pedal.
With the parts of the braking system out of the way, let’s look at why you might want to upgrade your brakes. The obvious reason is that the pads and/or rotors have worn out of material, which commonly occurs between 40-80,000 miles (yes, it’s a wide range, but it’s very dependent on your style of braking). The rotors can also become warped (you’ll feel a violent vibration when braking). On most modern Audi’s with stock brakes, you’ll see an indicator light pop up on the dash to let you know your pad life is getting low. However, some people choose to upgrade their brakes even though they’re not worn out. Some of the main reasons for upgrading are:
- Poor/weak/limp brake pedal feel
- Brake fade when pushed to the limit over and over again (common for those who track their cars)
- Warped rotors as a result of constant hard braking
- Visual upgrade to fill in the bigger wheels you run during the summer (OEM brakes look pathetic behind a nice 19″ wheel)
As with suspension, there are many different levels to which you can upgrade your brakes, from conservative to all out. As with anything, each level falls within a different price point and caters to a different audience. As for the list:
Replacement OEM Brakes
If you were happy with the way your stock brakes performed, but they’re worn out and need replacement, you can just toss in a new set of OEM pads and rotors. They’re very quiet, do a good job for most people, and have wear sensors to keep the car happy.
Aftermarket OEM-Sized Brakes
This is a popular option for those who want to keep the same wheels they have currently, but want more performance from their stock sized brakes. Upgraded pads and rotors (whether slotted or drilled) will create a noticeable improvement over the stock setup while retaining the same size components and same calipers. Some upgraded pads even include wear sensors. The pads come in all different varieties, from a pad that has OEM characteristics (such as low noise and low dust qualities) to a pad that is more suitable for heavy track duty with repeated hard braking. What suits you depends on how you’ll use it.
OEM Brakes From a Different Audi
This is another popular option for Audi enthusiasts. For years Audi owners have been swapping brakes with other Audi models for a cost effective upgrade. B5, B6, and B7 S4, A4 3.0L, and B7 RS4 brakes are all popular, bolt-on upgrades. They provide a great improvement in the stopping ability of the car while not costing as much as a big brake kit. Often times, they’ll also fit under stock wheels.
Big Brake Kit (BBK)
This is the ultimate braking upgrade. The best BBKs offer kits that range in size from 328mm to 355mm to a massive 370mm. Most BBK’s come with a floating rotor setup to help reduce warped rotors and rotor rings to make rotor replacement easier. The BBK’s are offered (generally) in a 4 or 6 piston setup (sometimes referred to as a “4-pot” or “6-pot” system). These almost always require a minimum of 18″ wheels (although the 328/332 kits will fit under 17″ wheels), but despite the increased size, they weigh quite a bit less than the outgoing OEM brakes (if you’ve ever held a B6 S4 front rotor, you know what I’m getting at). They also offer less brake fade and more stopping power (due to the extra pistons) than stock brakes physically can. Additionally, many BBK’s come with stainless steel brake lines which do not expand nearly as much under pressure, keeping a more even feel after all the abuse (stainless steel lines are a good upgrade for any braking application). The BBK’s are more expensive than the other options, starting at $2200 and going up from there.
This should give you a better understanding of some of the OEM and aftermarket options that are out there for your Audi. While this list is by no means all-encompassing, it does provide a glance at the directions you could go when you decide to upgrade the braking system. Since brakes are a wear and tear item, you’ll have to replace them eventually. At the same time, you should always replace/flush or at least re-bleed your brake lines with new brake fluid (we’ll do a DIY on this soon). A good brake upgrade/refreshing can do wonders for your driving experience and the car’s safety.
*Disclaimer: Obviously, better brakes are not the only thing that determines how well the car stops. Speed, reaction time, and traction all come into play as well, so drive smart!