Wilwood AERO4 rear big brake kit that replaces the factory rear discs on the BMW E90 325i and 328i while retaining the OE parking brake assembly. The kit pairs forged W4AR four-piston calipers in a red finish with oversized 14.00 inch GT-72 curved-vane slotted rotors and BP-10 compound brake pads, sized to match the OE master cylinder output, ABS function, and vehicle brake bias. It is designed as a rear complement to a Wilwood front big brake upgrade and clears most 18 inch and larger wheels (verify against the wheel clearance diagram). Kit includes calipers, rotors, brackets, pads, and braided stainless steel brake lines.
| Type | AERO4 rear big brake kit (OE parking brake compatible) |
| Position | Rear |
| Caliper | Forged W4AR four-piston, red finish |
| Rotor | 14.00 in GT-72 curved-vane slotted |
| Brake Pads | BP-10 compound |
| Contents | Calipers, rotors, mounting brackets, pads, braided stainless brake lines |
| Wheel Clearance | 18 in minimum (verify with clearance diagram) |
| Quantity | Complete rear axle kit |
This part fits:
| Year | Make | Model | Submodel |
|---|---|---|---|
| 2006 | BMW | 325i | Base |
| 2007-2013 | BMW | 328i | Base |
