ST XA Coilovers Porsche Boxster S / RS Spyder / Cayman S / Cayman R 987 (2004-2012) w/ Damping Adjustments - 18271016
ST XA Coilovers Porsche Boxster S / RS Spyder / Cayman S / Cayman R 987 (2004-2012) w/ Damping Adjustments - 18271016
The XA sits right in the middle of ST's lineup. It gives you everything the base ST X has, plus the 18-click external rebound adjustment that lets you tune feel for the road or the track without pulling the coilovers out. For a car like the 987 that already handles well from the factory, the ability to dial in rebound rather than being locked into a fixed damping rate is what makes the upgrade worth it. Street guys typically run the middle of the range and adjust from there based on tire and wheel weight. Track guys generally go firmer on the rebound to tighten up body movement under load.
Fitment Information
- Porsche Boxster 987 2.7L (2005, 2006, 2007, 2008)
- Porsche Boxster 987 2.9L (2009, 2010, 2011, 2012)
- Porsche Boxster S 987 3.2L (2005, 2006, 2007, 2008)
- Porsche Boxster S 987 3.4L (2009, 2010, 2011, 2012)
- Porsche Boxster RS Spyder 987 3.4L (2008, 2009)
- Porsche Cayman 987 2.7L (2006, 2007, 2008, 2009, 2010, 2011, 2012)
- Porsche Cayman S 987 3.4L (2006, 2007, 2008, 2009, 2010, 2011, 2012)
- Porsche Cayman R 987 3.4L (2011, 2012)
- Note: Vehicles equipped with PASM (Porsche Active Suspension Management) require the electronic damping system to be deactivated prior to installation. Deactivation kit KW part number 68510148, sold separately.
Fitment Note: This kit fits the Porsche 987 platform, which covers the second-generation Boxster (2005-2012) and first-generation Cayman (2006-2012), including the Boxster S, Boxster RS Spyder, Cayman S, and Cayman R. The Cayman was not introduced until the 2006 model year, so if your car is a 2004 or 2005 it is a Boxster only. The early 2004 Boxster (build date before November 2004) uses the previous 986 platform and is not covered by this kit. If your car has PASM from the factory, the PASM system must be deactivated before these coilovers are installed. Running PASM alongside aftermarket coilovers will result in a warning light and potential driveability issues. The deactivation kit (KW part number 68510148) is sold separately. An alignment is required after installation. Sold as a complete set of 4 coilovers.
Specs and Features
- ST Part Number: 18271016
- Sold as a complete set of 4 coilovers
- Made in Germany by ST Suspensions, developed in partnership with KW Automotive
- 18-click adjustable rebound damping, adjusted externally at the top of the chrome piston rod
- Increasing rebound stiffness improves track stability and reduces body roll; decreasing it softens the ride for street use
- Lowering range: 30-60mm (approximately 1.2-2.4 inches) front and rear
- Spring rate: 230 lbs/in front, 515 lbs/in rear
- Max axle load: Front up to 785 kg / Rear up to 940 kg
- Twin-tube damper construction with KW monoblock guide and multi-lip seal package
- Galvanized strut with additional corrosion-resistant coating for all-weather durability
- Continuous thread height adjustment via polyamide spring perch, adjustable even when installed
- Complete solution includes adjustable spring perch, race spring system, bump stops, and dust boot protection
- DOT compliant for street use
- Warranty: 1-year manufacturer warranty when purchased through Redline360 (Authorized Dealer)
Pairs well with:
- SPL Parts Rear Lower Control Arm Kit for Porsche Boxster/Cayman 987 (2005-2012) When you lower the 987, rear geometry moves around more than most people expect. These SPL billet lower control arms give you the adjustability to correct camber, caster, roll center, and anti-squat so the suspension is actually working for you after the drop, not just sitting lower.
Product Description
For drivers wanting more than just ride height adjustment we offer the ST XA coilover. Developed by KW Automotive the ST XA allows individual adjustment of the damping to suit just about all your driving needs!
ST XA coilovers feature KW damping technology which allows the suspension to be made either stiffer or softer depending on the driving conditions. This damping adjustment is made on the upper end of the chromed piston rod allowing the setup to be changed almost instantly. If the rebound force is increased, the car will drive with more track stability and reduced bodyroll. If the rebound force is decreased, the car will feel more comfortable on the move. Any vehicle fitted with ST XA coilovers will behave much more agile and sporty compared to stock.
With all ST coilovers the lowering adjustment is made via a continuously threaded strut housing on the galvanized strut. This even allows the lowering to be made even when the kit is installed by turning the spring perch higher or lower! NOTE: The lowering of each vehicle differs greatly with ST XA coilovers due to the types of suspension construction.
The high-quality ST XA coilover is based on the twin-tube damping principle of low friction combined with pressure-resistant damper housings. Manufactured directly at KW, a monoblock guide and multi-lip sealing package reduces the friction of the damper as well as protecting it against corrosion and dirt. Each galvanized strut is sealed multiple times to ensure maximum longevity.
OEM Part Numbers Cross Reference
- These coilovers replace the factory front strut assemblies and rear shock/spring units on the Porsche 987 platform
- Factory Porsche front strut assembly (987 Boxster/Cayman): 987-343-011-00, 987-343-012-00 (driver/passenger)
- Factory Porsche rear shock absorber (987): 987-333-057-01, 987-333-058-01 (driver/passenger)
Note: The OEM part numbers above are provided as reference to confirm what factory components these coilovers replace. Porsche part numbers can vary by model year and trim level within the 987 range. We recommend cross-checking your specific year and model via your dealer or realoem.com before ordering OEM replacement parts. The ST XA kit replaces all four corners as a complete system and is not intended to be mixed with factory components.
Original: $1,929.00
-70%$1,929.00
$578.70







Description
The XA sits right in the middle of ST's lineup. It gives you everything the base ST X has, plus the 18-click external rebound adjustment that lets you tune feel for the road or the track without pulling the coilovers out. For a car like the 987 that already handles well from the factory, the ability to dial in rebound rather than being locked into a fixed damping rate is what makes the upgrade worth it. Street guys typically run the middle of the range and adjust from there based on tire and wheel weight. Track guys generally go firmer on the rebound to tighten up body movement under load.
Fitment Information
- Porsche Boxster 987 2.7L (2005, 2006, 2007, 2008)
- Porsche Boxster 987 2.9L (2009, 2010, 2011, 2012)
- Porsche Boxster S 987 3.2L (2005, 2006, 2007, 2008)
- Porsche Boxster S 987 3.4L (2009, 2010, 2011, 2012)
- Porsche Boxster RS Spyder 987 3.4L (2008, 2009)
- Porsche Cayman 987 2.7L (2006, 2007, 2008, 2009, 2010, 2011, 2012)
- Porsche Cayman S 987 3.4L (2006, 2007, 2008, 2009, 2010, 2011, 2012)
- Porsche Cayman R 987 3.4L (2011, 2012)
- Note: Vehicles equipped with PASM (Porsche Active Suspension Management) require the electronic damping system to be deactivated prior to installation. Deactivation kit KW part number 68510148, sold separately.
Fitment Note: This kit fits the Porsche 987 platform, which covers the second-generation Boxster (2005-2012) and first-generation Cayman (2006-2012), including the Boxster S, Boxster RS Spyder, Cayman S, and Cayman R. The Cayman was not introduced until the 2006 model year, so if your car is a 2004 or 2005 it is a Boxster only. The early 2004 Boxster (build date before November 2004) uses the previous 986 platform and is not covered by this kit. If your car has PASM from the factory, the PASM system must be deactivated before these coilovers are installed. Running PASM alongside aftermarket coilovers will result in a warning light and potential driveability issues. The deactivation kit (KW part number 68510148) is sold separately. An alignment is required after installation. Sold as a complete set of 4 coilovers.
Specs and Features
- ST Part Number: 18271016
- Sold as a complete set of 4 coilovers
- Made in Germany by ST Suspensions, developed in partnership with KW Automotive
- 18-click adjustable rebound damping, adjusted externally at the top of the chrome piston rod
- Increasing rebound stiffness improves track stability and reduces body roll; decreasing it softens the ride for street use
- Lowering range: 30-60mm (approximately 1.2-2.4 inches) front and rear
- Spring rate: 230 lbs/in front, 515 lbs/in rear
- Max axle load: Front up to 785 kg / Rear up to 940 kg
- Twin-tube damper construction with KW monoblock guide and multi-lip seal package
- Galvanized strut with additional corrosion-resistant coating for all-weather durability
- Continuous thread height adjustment via polyamide spring perch, adjustable even when installed
- Complete solution includes adjustable spring perch, race spring system, bump stops, and dust boot protection
- DOT compliant for street use
- Warranty: 1-year manufacturer warranty when purchased through Redline360 (Authorized Dealer)
Pairs well with:
- SPL Parts Rear Lower Control Arm Kit for Porsche Boxster/Cayman 987 (2005-2012) When you lower the 987, rear geometry moves around more than most people expect. These SPL billet lower control arms give you the adjustability to correct camber, caster, roll center, and anti-squat so the suspension is actually working for you after the drop, not just sitting lower.
Product Description
For drivers wanting more than just ride height adjustment we offer the ST XA coilover. Developed by KW Automotive the ST XA allows individual adjustment of the damping to suit just about all your driving needs!
ST XA coilovers feature KW damping technology which allows the suspension to be made either stiffer or softer depending on the driving conditions. This damping adjustment is made on the upper end of the chromed piston rod allowing the setup to be changed almost instantly. If the rebound force is increased, the car will drive with more track stability and reduced bodyroll. If the rebound force is decreased, the car will feel more comfortable on the move. Any vehicle fitted with ST XA coilovers will behave much more agile and sporty compared to stock.
With all ST coilovers the lowering adjustment is made via a continuously threaded strut housing on the galvanized strut. This even allows the lowering to be made even when the kit is installed by turning the spring perch higher or lower! NOTE: The lowering of each vehicle differs greatly with ST XA coilovers due to the types of suspension construction.
The high-quality ST XA coilover is based on the twin-tube damping principle of low friction combined with pressure-resistant damper housings. Manufactured directly at KW, a monoblock guide and multi-lip sealing package reduces the friction of the damper as well as protecting it against corrosion and dirt. Each galvanized strut is sealed multiple times to ensure maximum longevity.
OEM Part Numbers Cross Reference
- These coilovers replace the factory front strut assemblies and rear shock/spring units on the Porsche 987 platform
- Factory Porsche front strut assembly (987 Boxster/Cayman): 987-343-011-00, 987-343-012-00 (driver/passenger)
- Factory Porsche rear shock absorber (987): 987-333-057-01, 987-333-058-01 (driver/passenger)
Note: The OEM part numbers above are provided as reference to confirm what factory components these coilovers replace. Porsche part numbers can vary by model year and trim level within the 987 range. We recommend cross-checking your specific year and model via your dealer or realoem.com before ordering OEM replacement parts. The ST XA kit replaces all four corners as a complete system and is not intended to be mixed with factory components.
















