3 year status update: CSG spec Brembo BM4 BBK on turbo 2017 w/ CSG C1 pad

[CSG Mike]

Originally posted Oct 28, 2021 elsewhere.

Almost exactly 3 years ago (Oct 26, 2018), I installed my CSG Brembo V2 BM4 BBK with C1 pads. I've been on the same pads and rotors since installation until yesterday. Here are my findings and some stats.

The rotor shows minor crazing, but zero signs of any cracks that threaten to touch either ID or OD on both inner and outer faces. Total rotor wear is 0.88mm at the thinnest point. There is a slight taper, with the ID of the rotor being slightly thicker. The Brembo rotor's durability shows here. The rotor shows a hint of pink temperature paint still present on the internal faces; the rest of the pink paint is white, indicating those areas have exceeded 610C at some point. Green paint is of course white, as it changes color at a lower temperature.

The outer pads have 5.05mm material remaining at the thinnest point, and 5.12mm at the thickest point. The inner pads exhibit slight taper, with the top (OD) edge having slightly less material. Thinnest point on the inner pad is 4.50mm, while thickest is 4.99mm. Likely cause is slightly uneven heat on inner vs outer rotor face, since my factory heat shield was retained, and I run zero ducting. Additionally, the 1 piece rotor will sink heat on the outer face only, leading that face to be cooler. Both inner and outer pads have exceeded 610C per the pink paint.

Caliper seals are fully intact, and readily pliable to the touch. All pistons retract easily and smoothly with just finger pressure. Per the temperature stickers on the caliper, the trailing (hottest) side never exceeded 232C. The rest of the caliper has never exceed 210C.

The system, while regularly visually inspected, has never been taken apart since both top and bottom of the pads are visible, as well as leading and trailing edges. The 3 year old brake dust easily wipes off with a microfiber. The brake retention bracket shows a half wiped state, as well as the "final" caliper face.

C2 rear pads were used on base model rear calipers. Pad wear is about 5mm on the front C1, whereas 9mm rear C2 wear is observed. I may be one of the few to wear rears faster than fronts.

About 41k mixed use miles are recorded during this period. Most of the miles early on are to/from tracks, canyons, and shops. Towards the last year, more street use is observed, due to the BRZ being the most practical car I own.

97 events are attended during these 3 years, 96 at a track, and 1 autox. A typical track session is between 2 and 8 laps, at power levels between 300whp and 360whp (dynojet). Approximately 40 full sessions were driven by experienced drivers other than myself.

Vehicle weight laden is typically between 2980lbs (track prepped, emptied, full tank, me in it), and 3260lbs (carry a lot of stuff to/from the track).
Excessive care was taken to properly bed and burnish the pads before their initial use.

The brake system was bled twice in this period. My original intent was to see how long I can go before the fluid seriously degraded where a bleed/flush would be mandatory, but this was foiled by a brake line failure. The failure was caused by the line being pulled through the stay, because the zip ties holding the line in place had disappeared. I speculate that the zip ties got brittle over time due to the radiant heat in the area from the brakes. Inspection oversight here for not noticing the missing zipties. The line that was pulled through abraded on the barrel of the wheel, eventually causing a pinhole leak and a near-complete loss of braking power. Line replacement necessitated a fresh flush. Project Mu G-Four was originally used, and replaced with Endless RF650.

The replacement rotors are Centric Premium, due to supply chain issues procluding the purchase of Brembo replacements. CP pads are installed front/rear, to better match my current use case for the car, as well as to satisfy my curiosity on whether a high end Street pad can survive light track duty.

Tires ranging from Pilot Super Sport to Toyo RR, and anything in between, were used during this 3 year testing period.