AST 5100 Series Coilovers Alpina RWD E90/E91/E92/E93 / BMW E88/E81/E82/E87 128i/135i/135is/323i/325i (ACU-B1601SD)

The AST 5100 Series Coilovers Alpina RWD E90/E91/E92/E93 / BMW E88/E81/E82/E87 128i/135i/135is/323i/325i is a coilover kit from AST Suspension. Part ACU-B1601SD.

Looking for the perfect road balance for everyday driving? The 5100 Street Suspension delivers comfort, control, and confidence in every corner. This monotube coilover system is 1-way adjustable for rebound and ride height, allowing you to fine-tune your setup for maximum grip and stability. It comes with vehicle-specific spring rates, OEM-compatible top mounts, and rebuildable dampers for long-lasting performance. Proudly made in the Netherlands, the 5100 STREET Suspension offers the ideal blend of everyday comfort and precise handling - engineered for drivers who want performance without compromise.

Features and benefits

Monotube dampers offer a large piston to control the adjustability of rebound damping. These dampers can adjust in rebound (return to extension). Front dampers utilize a coilover design, the rear is a divorced setup like OEM.

Details

• Brand: AST Suspension
• Series: AST 5100
• Part number: ACU-B1601SD
• Manufacturer description: AST 5100 Series Coilovers Alpina RWD E90/E91/E92/E93 / BMW E88/E81/E82/E87 128i/135i/135is/323i/325i
• Kit includes (partial list from the manufacturer data): 4 Shock absorbers

Fitment

• Vehicle: BMW 335i (E9X)
• Years and models on file: 2008-2013 BMW 128i Base; 2008-2013 BMW 135i Base; 2013 BMW 135is Base; 2006 BMW 325i Base; 2012-2013 BMW 328i Base; 2007-2013 BMW 328i Base; 2006 BMW 330i Base; 2007-2013 BMW 335i Base; 2011-2013 BMW 335is Base
• Suspension packages vary within a model line (electronic dampers, engine, body style and drive type). Compare the application above with your car before ordering. Not sure? Ask us and we will check it against your VIN.

Before you order

Coilover kits are built for a specific chassis, drivetrain (RWD / AWD) and model range. Compare the manufacturer description above with your car. Cars with factory electronic dampers (for example EDC, PASM or adaptive M suspension) may need a cancellation kit, which is not included unless listed. An alignment is needed after installation. Questions? Ask us.

About AST Suspension

AST (Advanced Suspension Technology) is a Dutch suspension brand. It develops monotube coilover systems and lowering springs for road and track cars, from 1-way street setups to 3-way motorsport dampers, and its coilovers are engineered and made in the Netherlands.

Shipping & returns

• Orders are processed within 1–3 business days; standard delivery is 3–7 business days within the United States.
• Special order: this item is ordered from the manufacturer after you place your order. It is not shipped from stock and can take several weeks. We email you the expected ship date after you order.
• We currently ship within the U.S. only. See our Shipping Policy.
• 30-day returns on unused parts in original packaging — see our Return Policy.

Installation at Team ANBD

Team ANBD is a performance shop in Andover, New Jersey. An alignment is recommended after any ride-height change, and we can align or corner-balance the car, and prep track cars. Book an appointment or ask us about installation and fitment before you order.