AST Suspension 5100 Street Series Coilovers - 2019+ BMW 1-Series (F40)

The AST Suspension 5100 Series suspension for 2019+ BMW 1 Series (F40) provides a tunable damper system for drivers developing a setup around their vehicle, tires and intended use.

Rebound adjustment changes resistance as the suspension extends after compression. It provides a focused damping adjustment for evaluating how the car recovers from bumps and responds between braking, cornering and acceleration. Work from a recorded baseline rather than assuming the firmest setting produces the best response.

Key specifications

• Adjustable rebound damping.
• Monotube damper construction.
• Rebuildable dampers.
• Ride-height adjustment on the supported configuration.
• OEM top-mount compatibility is application-dependent; do not assume replacement mounts are included.
• Manufacturer part number: ACU-B1406S.

Damper construction follows the suspension layout. Do not assume every unit is inverted or that every upper mount provides camber adjustment. Exact mount configuration and any application-specific installation requirements should be checked for this part number.

Installation and setup

Check the application, wheel clearance and suspension travel before selecting the final ride height. Establish alignment and, where appropriate, corner weights before tuning damping. Change one setting at a time and record the result so a useful baseline can be restored.

Vehicle fitment