The billet plenum fixes the three things wrong with the factory one: it's plastic, it cracks under boost, and it feeds the three cylinders unevenly.
Billet | O-ring sealed | Throttle body relocated | X3, all years
The factory plenum isn't just a restriction. It's where the uneven pressure that kills X3 head gaskets comes from. This one distributes evenly, seals properly, and takes boost the plastic never could.
All orders are hand built once payment in full has been received. Typical ship times are 1-3 business days