http://dfurseth.blogspot.com/: Review of EBC Stage 4 Signature Big Brake Kit S4KF1177 (front) and S4KR1019 (rear) for a BMW X3 E83

Overview: EBC Stage 4 Signature Big Brake Kits S4KF1177 (front), and S4KR1019 (rear) installed on a 2004 BMW X3 3.0i E83. I am currently 6 weeks in and have driven roughly 1000 miles. I gave them the full 200 mile break-in period of light braking, followed by EBC’s recommended “final bedding” run: five (5) heavy braking events from 60mph down to 20mph in quick succession. I then went on a 30 minute aggressive drive though a few mountain roads and gradually cooled the brakes on the freeway after. Everything is smooth. no squawks, squeaks, squeals.

About the kit(s): Front kit is 12.8 in. diameter, rear is 12.6 in. All rotors are directional with angled internal vents. If you install these backwards, you will probably get "whirl" noise caused by irregular airflow. Rear rotors have the integrated e-brake contact surface in the inside which makes them more expensive, kit does not include new e-brake pads. Both kits include EBC's URS Slotted Rotors with anti-corrosion black anodized finish. These are combined with carbon ceramic ultra-low dust "Red Stuff" pads. EBC maintains these pads are a 90% reduction in dust over OEM pads...that is one hell of a claim.

My observations: brake dust was fairly normal/heavy during the break-in period. This is to be expected while the pads set and the rotor surfaces clean up... Post break-in period, would I say the 90% reduction is true. I'm currently on day 7 from the last wash with no sign of dust anywhere on the wheels or body. Previously (OEM pads) brake dust would build up on my rear bumper and inner wheel surfaces within days of a wash. Very happy about that. Stopping power is noticeably better than OEM, and I don't have any brake fade that I had become accustom to on long drives in the hills with OEM pads. So the Red Stuff pads are working nicely! I will note that I chose these pads for the ultra-low dust rating, not stopping power. If you are after more serious braking (especially for towing), get EBC's "Green Stuff" SUV pads (still less dust than OEM), just more bite. EBC also makes the insane race level "Yellow Stuff" pads, but these swap massive amounts of dust for insane bite - not great for the street. and I doubt anyone is racing E83's with the exception of a few Russian rally teams, ha!.. Hope this helps if you are considering a brake upgrade. Happy driving.