ST X Coilovers Porsche Boxster 987 04-13

ST X Coilovers for Porsche Boxster 987 (2004-2013) – 30-60 mm Lower, Height Adjustable, Fixed Damping

This ST X kit replaces the standard springs and dampers on the Porsche Boxster 987 (2004-2013) with a height-adjustable coilover set. It lowers the car by approx. 30-60 mm front and rear, which sharpens the steering, cuts body roll and closes up the wheel arch gap. The ride height is set on threaded struts, so you can go for a subtle drop or use the full approved range, and change it again later.

The ST X is the entry point to the ST range. It is built around a damper setting that ST have matched to this specific car, so there is nothing to adjust beyond ride height. Shaped (progressive) springs keep the ride compliant over small bumps and firm up as the suspension compresses, which makes it a good fit for a daily driver that needs to look lower and feel tighter without becoming harsh. ST is part of the KW automotive group, and the kit is developed and made in Germany using KW engineering.

This kit is for the Porsche Boxster 987 (Inc Boxster S, RS Spyder) with the 2.7, 2.9, 3.2, 3.4, 3.4 RS 60, R 3.4, S 3,4 Sport, S 3.2 and more, up to a 785 kg front axle load. Check the Fitment section below before ordering.

Specifications

• Front lowering: approx. 30-60 mm
• Rear lowering: approx. 30-60 mm
• Max front axle load: up to 785 kg
• Max rear axle load: up to 940 kg
• Height adjustment: Stepless, on threaded strut housings
• Damping: Fixed, pre-set by ST for this vehicle
• Springs: Shaped progressive springs
• Strut housings: Galvanised steel
• Approval: Parts certificate (German §19.3)

Lowering figures are ST's, measured against the standard car. The actual drop varies with engine, equipment and tolerances on each car, and the springs settle slightly after the first few hundred miles.

Key Features

• Stepless ride height adjustment on a coarse, dirt-resistant trapezoidal thread
• Damper setting developed by ST for this vehicle, so no setup is needed beyond ride height
• Shaped progressive springs for a comfortable ride with firmer support in corners
• Galvanised, multi-sealed steel strut housings for long-term corrosion protection
• Composite spring perches with stainless steel inserts that stay easy to adjust for years
• Dust covers and bump stops protect the damper seals and act as an extra spring under heavy load
• Developed and built in Germany, based on KW engineering
• Supplied with a parts certificate and fitting instructions

What's in the Kit?

• 2 x height-adjustable front coilover struts with springs
• 2 x height-adjustable rear coilover struts with springs
• Composite spring perches with stainless steel inserts
• Dust covers and bump stops
• Parts certificate and fitting instructions

Please note: the photos are ST's own images of this kit. Small details such as brackets can differ from the photos.

Fitment

• Porsche Boxster 987 (Jun 2004 to Dec 2013)
• Porsche Boxster Spyder 987 (Sep 2007 to Dec 2013)
• Porsche Cayman 987 (Nov 2005 to Dec 2013)
• Engines: 2.7, 2.9, 3.2, 3.4, 3.4 RS 60, R 3.4, S 3,4 Sport, S 3.2, S 3.4

Not suitable for: any vehicle not listed above. Contact us with your registration if you are unsure.

Installation

Fitting means removing the original struts, springs and dampers and fitting the ST units in their place. We recommend a qualified workshop experienced with coilovers. A spring compressor is needed to strip down the original front struts. The original top mounts, bearings and fixings are reused, so check them for wear and replace any that are worn. Set the ride height within the approved range, tighten the suspension bolts with the car's weight on its wheels, and torque everything to the manufacturer's figures. A four-wheel alignment is required once the car is at its final ride height. Re-check the height and alignment after the first few hundred miles, once the springs have settled.

Download ST's documents for this kit: Fitting instructions (PDF), Parts certificate (PDF).

Before you start:

• If the car has Porsche Active Suspension Management (PASM), the system must be switched off.
• Disconnect any ride height sensors (headlight levelling or self-levelling) before removing the old struts.
• Clean the threads before adjusting, and start with the height adjusters in the middle of their range.

After fitting:

• Expect the car to settle a further 5-10 mm once it has been driven, then re-check the height.
• Check there is at least 5 mm clearance between the tyres and the suspension through the full steering and suspension travel.
• Have the headlight aim reset, along with any other height-dependent systems.
• ESP/ABS warning lights can appear after fitting. Some clear after a short drive, others need full steering lock both ways or a reset with a diagnostic tool.
• On cars with radar or camera driver assistance systems, have the calibration checked after lowering.

Upgrade Further

Want to fine-tune the ride? The ST XA Coilovers Porsche Boxster 987 04-13 adds 16-click rebound adjustment.

Will this fit my Porsche Boxster 987?

It fits the Porsche Boxster 987 (2004-2013) with the 2.7, 2.9, 3.2, 3.4, 3.4 RS 60, R 3.4 and more. Check the Fitment section for the body styles and exclusions, or send us your registration and we will check.

How low will my Porsche Boxster 987 sit?

ST quotes a drop of approx. 30-60 mm front and rear compared with standard. The exact drop varies from car to car with engine, equipment and tolerances.

Can I adjust the damping?

No, the damping is pre-set by ST to suit the springs, so there is nothing to set up. You only adjust the ride height. If you want adjustable damping, look at the ST XA.

Will the ST X make my Porsche Boxster 987 ride harshly?

The ST X uses progressive springs and a fixed damper setting chosen by ST for this car, so it is firmer than standard but still suits everyday driving. Lowering a long way or fitting low-profile tyres will firm up the ride more than the coilovers themselves.

Do I need an alignment after fitting?

Yes. Changing the ride height changes camber and toe, so a full four-wheel alignment is needed once the car is at its final height, and again after any later change.

Is it road legal in the UK?

Yes. It is designed for road use and comes with a German parts certificate. Keep the ride height within ST's approved range and tell your insurer about the modification.

What is the difference between ST and KW coilovers?

ST is part of the KW group and its coilovers are made in Germany using KW engineering. ST uses galvanised steel strut housings and offers fewer adjustment options than KW's stainless steel Variant range, which keeps the price lower.

Is it covered by a warranty?

Yes, ST covers it against defects in materials and workmanship. If a part ever needs replacing, contact us with your vehicle details and order number.