SPL's billet rear lower trailing arms replace BMW's stamped-steel arms on the E8X/E9X, stiffening the rear suspension and cutting unsprung weight.
Improved rigidity
Under hard acceleration and braking the factory arm can flex several millimeters. Combined with the soft OEM bushings, that deflection shows up as rear bump steer and instability. The SPL arm stays put, and won't bend like the OEM pieces.
Reduced weight
At 0.75 lb (0.34 kg) per side, each arm is about 35% lighter than OEM. Less unsprung mass means better wheel control over bumps and less wheel hop.
Specifications
- 6061-T6 billet aluminum, anodized black
- Zinc-plated class 10.9 metric hardware
- No change to noise, vibration or harshness (NVH)
- Sold as a pair (left and right)
- SPL part number: SPL RTR E9X
- Replaces OEM 33322406291 / 33326763477
Fitment
- 2008-2013 BMW M3 (E90, E92)
- 2006-2013 BMW 3 Series (E90, E91, E92, E93)
- 2008-2013 BMW 1 Series (E81, E82, E82 1M, E87, E88)