The Bilstein B8 (SP) 35-120407 is a front-left (driver side) strut assembly built on Bilstein's monotube, gas-pressure design, and it is tuned for BMW 3-Series chassis that run lowering springs or sport suspension. Owners on user forums describe the B8 as the sport-oriented Bilstein for lowered cars, with the B6 as the choice for stock-height suspension. That positioning matters: a complete B8 strut pairs the damper with the correct valving for a lowered car, so you avoid the harsher or mismatched feel of a generic performance strut. It also supports sharper body control under hard cornering and on aggressive, track-day driving, while staying livable on the street. Keywords: Bilstein B8 SP front strut, 35-120407 monotube strut, BMW E90 328i lowered front strut, E92 335i sport strut replacement.
Owners on user forums list 35-120407 as the front-left B8 for E90-generation 3-Series cars, so it is the driver-side unit. The passenger side uses a separate part number.
User forums consistently describe the B8 as designed for lowered cars with aftermarket lowering springs. Owners note that pairing it with factory springs is not what the product was designed for, so confirm the intended setup with the manufacturer before ordering.
Front strut replacement on an E90 is a moderate-difficulty job for a home mechanic with solid tools and patience. Owners on user forums recommend lifting the car on jackstands, supporting the front control arm with a floor jack, and removing the sway bar end link and the strut-to-knuckle pinch bolt. Expect to spread the steering knuckle clamp to free the strut, and remove the strut brace and three upper mount nuts before lowering the assembly out. Many owners pull the caliper and rotor and zip-tie the caliper aside to avoid stressing the brake hose, and they photograph hose and wire routing before disassembly. A long-reach metric socket set and a spring compressor are useful if you are transferring springs to a new strut. Check torque specifications with the manufacturer's service information before reassembly, and get a professional alignment afterward.
