Girodisc Front Rotors for BMW E46 M3, A1-012

If you're looking to upgrade your E46 M3's braking performance, these GiroDisc 2-piece rotors are a solid choice. They’re a direct swap for the stock 345mm rotors found on the Competition Package (ZCP) and CSL models. What’s cool is that they weigh in at just 17.5 lbs each, compared to the factory rotors at 19 lbs. That might not seem like much, but every little bit counts when it comes to unsprung weight and rotating mass—especially if you’re pushing your M3 to its limits.

These rotors are crafted from a unique high-carbon steel that GiroDisc has specially formulated. This isn't just marketing fluff; the metallurgy really holds up under pressure. They come with 48 curved vanes that act like a little centrifugal pump, pulling in air through the hub to keep things cool even during those intense track days. And the beauty of the 2-piece design? You can reuse the hat when it's time to replace the rings (part number D1-012), which is a nice touch for anyone looking to save a bit of cash down the line.

Speaking of the hat, it’s made from 6061-T6 aluminum and given a black anodized finish, which not only looks great but also adds durability. The drive pins are made from a high-strength steel alloy and are cadmium-plated to resist corrosion. Everything is assembled with spring clips and Belleville washers, so you get that race-ready float without worrying about noise from loose hardware when you’re just cruising around town.

These rotors are designed to work seamlessly with common aftermarket caliper setups, as well as the stock sliding calipers on ZCP and CSL cars. If you're considering upgrades like Brembo calipers from the Porsche 996 or even the Megane RS swaps, these rotors will fit right in.

To give you some quick specs: the diameter is 345mm, thickness is 28mm, and they weigh 17.5 lbs per rotor assembly. Just keep in mind, if the thickness drops below 26mm or if you spot a crack reaching the edge of the ring, it’s time for a replacement.