r/wrx_vb•
jmznxn77

Will a BBK upgrade increase unsprung weight substantially?

Looking at doing 4/2 brembos with a TR knuckle swap on my '25, and I'm having quite a difficult time finding weights of the stock VB rotors/calipers, as well as the OEM 08-17 STI rotors/calipers (and the aftermarket options, e.g. the R1 Concepts eLINE Series Drilled & Slotted). Why does it seem like nobody lists rotor weight in their specs?

I have concerns about how the larger rotors, if not designed to be lighter, would add quite a lot of unsprung weight and effect the handling. Am I overthinking this, or is this a real cause for concern?

Posted Aug 14, 2025, 12:26 AM UTC

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