Tein GSS84-8USS2 Street Basis Z Coilovers 2008-2014 Subaru WRX STI GRF GVF AWD

Vehicle Fitment

• 2008-2014 Subaru WRX STI 5-Door Hatchback (GRF Chassis, AWD)
• 2011-2014 Subaru WRX STI 4-Door Sedan (GVF Chassis, AWD)

Fitment Notes

• AWD applications only - designed for GRF (5-door/wagon) and GVF (4-door sedan) STI chassis
• Does not fit the 2008-2014 Subaru WRX (non-STI) - for WRX fitment use GSS80-8USS2
• Does not fit the 2015+ VA-chassis WRX/STI - for VA fitment use GSSB0-8USS2
• Uses the vehicle's factory upper mounts - OEM upper mounts must be transferred from the existing struts and are not included
• Not compatible with EDFC (Electronic Damping Force Controller) - damping is fixed
• Ride height adjustment range varies by body style:
  • 5-Door Wagon (GRF): Front -0.9 in. to -2.8 in. / Rear -0.2 in. to -3.0 in.
  • 4-Door Sedan (GVF): Front -0.9 in. to -2.8 in. / Rear -0.2 in. to -2.6 in.
• Recommended lowering range: 25-45 mm front / 10-30 mm rear

Features

• Thread-type full-length ride height adjustment via ZT-coated threaded sleeve - lower spring seat moves independently of spring preload for accurate, repeatable height setting
• Twin-tube damper construction delivers longer stroke with lower repulsive force compared to mono-tube designs, improving ride compliance on varied road surfaces at lowered heights
• Matched spring and damper valving developed specifically for this application - eliminates compatibility guesswork of pairing separate springs with a performance shock
• Shortened shell case design optimises damper stroke at lowered ride heights, maintaining adequate suspension travel and ride quality when set within the recommended range
• Cold-formed SAE9254 steel springs with a minimum tensile strength of 200 kgF/mm² - sag-resistant and highly resilient under sustained load
• Dust boots protect the piston rod and damper internals from dirt and debris (some applications use OE dust boots)
• High-performance Tein damper oil maintains stable viscosity across a broad temperature range for consistent damping performance
• ZT Coating surface treatment on threaded sleeve for corrosion resistance and long-term thread durability
• Powder-coated spring finish for superior rust protection that resists peeling and flaking

Specifications

• Part Type: Coilover Kit - Shock Absorber and Spring (4 corners)
• Series: Street Basis Z
• Damper Type: Twin-tube, fixed damping
• Front Spring Rate: 7 kgF/mm (392 lb/in)
• Rear Spring Rate: 5 kgF/mm (280 lb/in)
• Front Lowering Range: ~0.9 in. - 2.8 in. below stock
• Rear Lowering Range: ~0.2 in. - 3.0 in. below stock (wagon) / ~0.2 in. - 2.6 in. (sedan)
• Damping Adjustment: Fixed (non-adjustable)
• EDFC Compatibility: No
• Upper Mounts: Not included - OEM upper mounts required
• Spring Material: SAE9254 cold-formed steel
• Warranty: 1 year (manufacturing defect and sag over 5mm; excludes powder coat finish and rusting)

Included Components

• 4x Coilover Assemblies (shock absorbers with integrated springs)
• Dust Boots (application-dependent; some applications use OE dust boots)
• 1x Warranty Information and Bump Stop Reference Guide

Product Description

The Tein Street Basis Z (GSS84-8USS2) is an entry-level height-adjustable coilover kit for the 2008-2014 Subaru WRX STI in both 5-door hatchback (GRF) and 4-door sedan (GVF) configurations. Designed as Tein's most accessible coilover offering, the Street Basis Z is engineered specifically for daily-driven STIs where stance improvement and enhanced handling are the primary goals - without the complexity or cost of a fully adjustable damping system. The kit pairs purpose-valved dampers with matched springs that Tein has developed and road-tested specifically for this application, removing the compatibility uncertainty that comes with mixing separate spring and shock brands.

Ride height is adjusted via the threaded lower spring seat on the ZT-coated sleeve, which allows height changes without altering spring preload. The twin-tube damper layout provides a comfortable ride even at lowered heights, with the shortened shell case maintaining sufficient damper stroke across the recommended 25-45 mm front and 10-30 mm rear lowering range. The kit uses the factory upper mounts, which must be transferred from the OEM struts. Damping is fixed - for owners who want 16-stage damping adjustment and EDFC compatibility on the same GRF/GVF STI platform, the Street Advance Z is available as an upgrade. Backed by Tein's 1-year warranty covering manufacturing defects and spring sag exceeding 5mm.