{"product_id":"bc-racing-zx-series-coilovers-2017-audi-a4-s4-53mm-front-strut-b9","title":"BC Racing ZX Series Coilovers for 2017+ Audi A4\/S4 (53mm Front Strut) (FWD\/AWD) (B9)","description":"\u003cp\u003eBC Racing ZX Series Coilovers for the 2017+ Audi A4\/S4 (B9) bring the same three-axis adjustability as the race-spec ZR Series with valving tuned for drivers who split time between street and track. Every kit is extensively tested on the B9 chassis and refined until it balances ride quality with performance — the reason A4\/S4 (53mm Front Strut) coilovers from BC Racing are the best-selling adjustable kits in their segment worldwide.\u003c\/p\u003e\n\u003cp\u003eZX Series kits share the three-axis damper architecture of the race-spec ZR Series, tuned out of the box for drivers who want race-grade adjustability without the ride harshness on the commute home. BC Racing takes pride in choosing spring rates and damper valving that balance comfort and performance — you never end up with the oversprung, harsh-riding kit some brands ship as their only option. Drivers who want to deviate from the factory setup can order Swift Springs, custom spring rates, and custom valving at checkout; BC will re-valve the dampers to match whatever you specify, a level of customization most brands reserve for their top-tier race kits.\u003c\/p\u003e\n\u003cp\u003eSince 2004, BC Racing has grown into one of the most trusted names in aftermarket coilovers — not by racing to the bottom on price, but by pairing that price with real build quality, deep customization options, and a damper design any suspension shop can rebuild instead of replacing. These A4\/S4 (53mm Front Strut) coilovers arrive tuned for the B9 chassis and ready to bolt in — no break-in period, no guessing at setup. Every kit ships with a 2-year manufacturer warranty, lifetime access to BC service parts (pistons, seals, shafts — no unit replacement required when it's time for a rebuild), and in-house tech support from both BC Racing and the Springrates team.\u003c\/p\u003e\n\u003ch3\u003eFeatures\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e30-level rebound adjustment\u003c\/li\u003e\n\u003cli\u003e15-level low-speed compression adjustment\u003c\/li\u003e\n\u003cli\u003e12-level high-speed compression adjustment\u003c\/li\u003e\n\u003cli\u003eInverted mono-tube damper with linear twin-piston design\u003c\/li\u003e\n\u003cli\u003eRide height adjustable independent of spring preload\u003c\/li\u003e\n\u003cli\u003eUpper mount hardware varies by chassis — camber plates, pillowball, or reused OEM mounts. See the Specifications table for what's included on your kit.\u003c\/li\u003e\n\u003cli\u003eSwift Spring and custom spring rate upgrades available at checkout\u003c\/li\u003e\n\u003cli\u003eCustom damper valving paired with custom spring rates on request\u003c\/li\u003e\n\u003cli\u003eFully rebuildable — replacement parts available from BC for the life of the shock\u003c\/li\u003e\n\u003cli\u003e2-year manufacturer warranty against defects\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch5\u003eSpecifications\u003c\/h5\u003e\n\u003ctable class=\"table table-striped table-primary\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003ePart Number\u003c\/td\u003e\n\u003ctd\u003eS-27-ZX\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePart Name\u003c\/td\u003e\n\u003ctd\u003eZX Series Coilovers\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eVehicle\u003c\/td\u003e\n\u003ctd\u003e2017+ Audi A4\/S4 (53mm Front Strut) (FWD\/AWD) (B9)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDrivetrain\u003c\/td\u003e\n\u003ctd\u003eFWD\/AWD\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eChassis Code\u003c\/td\u003e\n\u003ctd\u003eB9\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDamping Adjustment\u003c\/td\u003e\n\u003ctd\u003e3-Way (30 levels rebound 15 LSC 12 HSC)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eRide-Height Adjustable\u003c\/td\u003e\n\u003ctd\u003eYes\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSpring Rate - Front\u003c\/td\u003e\n\u003ctd\u003e10 kg\/mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSpring Rate - Rear\u003c\/td\u003e\n\u003ctd\u003e8 kg\/mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSpring Size - Front\u003c\/td\u003e\n\u003ctd\u003e62-220-10K\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSpring Size - Rear\u003c\/td\u003e\n\u003ctd\u003e62-190-8K\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSwift Springs - Front\u003c\/td\u003e\n\u003ctd\u003e62-203-X\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSwift Springs - Rear\u003c\/td\u003e\n\u003ctd\u003e62-178-X\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCamber Plates - Front\u003c\/td\u003e\n\u003ctd\u003eNot Applicable\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCamber Plates - Rear\u003c\/td\u003e\n\u003ctd\u003eNot Applicable\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSuspension Design - Front\u003c\/td\u003e\n\u003ctd\u003eTrue Coilover\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSuspension Design - Rear\u003c\/td\u003e\n\u003ctd\u003eTrue Coilover\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eNotes\u003c\/td\u003e\n\u003ctd\u003e\u003cul\u003e\n\u003cli\u003eDesigned for 53mm front strut diameter — measure yours before ordering.\u003c\/li\u003e\n\u003cli\u003eThe ZX Series is not available in Extreme-Low configuration.\u003c\/li\u003e\n\u003c\/ul\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003ch5\u003eVehicle Fitment\u003c\/h5\u003e\n\u003cul\u003e\n\u003cli\u003e2017 Audi A4\/S4 (53mm Front Strut) (FWD\/AWD) (B9)\u003c\/li\u003e\n\u003cli\u003e2018 Audi A4\/S4 (53mm Front Strut) (FWD\/AWD) (B9)\u003c\/li\u003e\n\u003cli\u003e2019 Audi A4\/S4 (53mm Front Strut) (FWD\/AWD) (B9)\u003c\/li\u003e\n\u003cli\u003e2020 Audi A4\/S4 (53mm Front Strut) (FWD\/AWD) (B9)\u003c\/li\u003e\n\u003cli\u003e2021 Audi A4\/S4 (53mm Front Strut) (FWD\/AWD) (B9)\u003c\/li\u003e\n\u003cli\u003e2022 Audi A4\/S4 (53mm Front Strut) (FWD\/AWD) (B9)\u003c\/li\u003e\n\u003cli\u003e2023 Audi A4\/S4 (53mm Front Strut) (FWD\/AWD) (B9)\u003c\/li\u003e\n\u003cli\u003e2024 Audi A4\/S4 (53mm Front Strut) (FWD\/AWD) (B9)\u003c\/li\u003e\n\u003cli\u003e2025 Audi A4\/S4 (53mm Front Strut) (FWD\/AWD) (B9)\u003c\/li\u003e\n\u003cli\u003e2026 Audi A4\/S4 (53mm Front Strut) (FWD\/AWD) (B9)\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"BC Racing","offers":[{"title":"Default Title","offer_id":63498230956401,"sku":"S-27-ZX","price":2495.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/2534\/9336\/files\/bc-racing-zr-series-hero.jpg?v=1740535651","url":"https:\/\/bc.springrates.com\/products\/bc-racing-zx-series-coilovers-2017-audi-a4-s4-53mm-front-strut-b9","provider":"BC Racing - Springrates.com","version":"1.0","type":"link"}