What: As on the former car, I replaced the heavy N American rear bumper bar with a svelte Euro-spec 330i bumper bar to lose an easy 11 lbs while taking zero hits in daily drive-ability and safety.
Euro 330i bumper bar part # 51127058467
RealOEM
DIY:
BMW Rear Bumper Replacement
Why: Losing weight directly improves all driving dynamics. Also, I prefer the dynamic agility of a ~290 Hp 3250 lb car to a 500 Hp 4000 lb car.
Results: Less mass = less inertia -> more fun. In anticipation of some who argue 10 lbs is insignificant, I would counter that the process is cumulative. I've dropped 150 lbs since taking delivery, including nearly 40 lbs of unsprung, rotational mass.
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2011 6MT RWD ClubSport Wagon | 3,185lbs | 1 of 149 ZSPs delivered in North America
Outside: BMW M-Aero, Euro region lighting, Seibon | Inside: M3 cockpit, Recaro SPG, Prototipo, AutoSolutions SSK, UCP | Stop: M3 ST-40R, PFC | Grip: Solid-mounted subframes, rear coilover conversion, M3 Nitron R3, Hyperco, SPL, AKG, ARC8 | Go: StageFP, CF snorkel, 3IM, MILVs, SuperSprint headers, Dundon Motorsports Inconel exhaust, VoltPhreaks | Cool: CSF | PCA #2018100384 | BMW CCA #505794