IRP rear axle upper shock mount bracket for the BMW 1, 2, 3 and 4 series of the F20-F36 F80-F87 and G20-G26, G42 and G80-G87 chassis models.
Also used on the Mini F56-F60 and BMW 1 series/X1/X2 F39-F48
What exactly does it do?
- It replaces the standard rubber lower mounts of the rear shock absorbers with a solid, CNC-machined aluminum version with monoball (spherical bearing / pillow ball).
- Advantages in drift/track use:
- Eliminates deflection (bending) and sagging of the original rubber mounts, which quickly wear out or collapse under hard loads.
- Gives a much more direct and precise feel to the rear suspension.
- Improves handling, stability and response during hard braking, acceleration and cornering.
- Prevents premature wear or failure of mounts.
- Disadvantage: It makes the suspension stiffer, so more vibration and noise may come through into the cabin (less comfort on the street).
This is a popular upgrade in the drift and racing community, similar to the IRPRSM-90B (monoball version for E8x/E9x) or polyurethane variants, but specifically in aluminum for F-chassis.