This Apec Brake Disc – Front (SDK6103) Fits BMW has been precision-crafted for consistency and is part of the Apec Blue range. Z4 Petrol Convertible 3.0i 2979cc 170KW 231HP M54 B30 (306S3). Z4 Petrol Convertible 2.5si 2497cc 160KW 218HP N52 B25 A.