Product Details
The Riaction TPU Coilovers for the 1992-2000 Subaru Impreza WRX STI bring Riaction's digressive damper technology to the Subaru Impreza WRX STI, engineered for drivers who prioritize high-speed control, flatter cornering, and sharper response than a linear coilover can deliver. Each TPU set is built-to-order so valving and spring selection are matched to your exact Subaru Impreza WRX STI application, with the same 32-level damping adjustment and full-length ride-height range you'd expect from the Riaction platform.
Digressive pistons give the TPU a higher initial damping rate at low shaft speeds (body roll, weight transfer) and relax over big inputs (potholes, curb strikes), so you get better control without the harshness of a stiffer linear tune. Riaction coilovers for the 1992-2000 Subaru Impreza WRX STI ship fully rebuildable and backed by a 2-year warranty, making the TPU a long-term investment for enthusiasts serious about their Impreza WRX STI setup.
TPU Series Technology
- Digressive piston design — high control at low shaft speeds, compliant over big hits
- 32-level damping adjustment (1-Way)
- Monotube damper with seamless 52mm electroplated carbon steel body
- 44mm CNC-machined 6061 aluminum piston
- Built-to-order valving matched to vehicle and spring rate
- SAE9254 cold-wound linear main springs
- Multi-thickness valving shims for precise damper tuning
- Polyurethane oil seals and 7.5W suspension fluid
- Fully rebuildable — built to be serviced, not replaced
Features
- Full-length ride-height adjustment (preload-independent)
- 32 levels of damping adjustment
- Digressive valving for better control under load
- Front camber adjustment via pillowball top mounts
- Optional Swift Springs upgrade (sold separately)
- Built-to-order — 2-4 week lead time typical
- 2-year limited warranty
TPU vs GT1 — Which Is Right for You?
Both kits share the same 52mm monotube damper body, 32 levels of damping, full-length ride-height adjustment, and spring rates. The difference is in how the damper reacts:
The GT1 uses a linear piston — good low-speed control for body roll, turn-in, and weight transfer, with damping that follows a predictable curve through bumps. That balance makes it the right call for street, canyon, and occasional track days. The TPU runs a digressive piston that sharpens low-speed response with higher initial resistance for flatter cornering, then softens at higher shaft velocities — a blow-off behavior that relieves harshness over potholes, curbs, and expansion joints. The TPU is built for track-focused driving, autocross, and aggressive street use where you want the extra bite under load.
Short version: choose GT1 if you want the best daily-street-track balance — typically in stock and ship-ready. Choose TPU if you want tighter response under load and don't mind the lead time on a built-to-order digressive tune.
Specifications
| Part Number | SB-005-LT-TPU |
| Part Name | Riaction TPU Coilovers |
| Vehicle | 1992-2000 Subaru Impreza WRX STI |
| Adjustment Type | 1-Way |
| Damper Valving | Digressive |
| Ride-Height Adjustable | Yes |
| Spring Rate - Front | 8 Kg/mm |
| Spring Rate - Rear | 4 Kg/mm |
| Top Mounts - Front | Pillowball with camber plate |
| Top Mounts - Rear | OEM |
| Camber Plates - Front | Yes |
| Camber Plates - Rear | No |
| Suspension Design - Front | True Coilover |
| Suspension Design - Rear | True Coilover |
| Built-to-Order | Yes |
| Notes | Front camber plate |
Vehicle Fitment
- 1992 Subaru Impreza WRX STI
- 1993 Subaru Impreza WRX STI
- 1994 Subaru Impreza WRX STI
- 1995 Subaru Impreza WRX STI
- 1996 Subaru Impreza WRX STI
- 1997 Subaru Impreza WRX STI
- 1998 Subaru Impreza WRX STI
- 1999 Subaru Impreza WRX STI
- 2000 Subaru Impreza WRX STI