Product Details
The Riaction TPU Coilovers for the 2014-2017 Lexus IS300h deliver a premium, adjustable suspension upgrade built for drivers who want more from their IS300h than the factory setup can offer. These Lexus IS300h coilovers are engineered to pair street comfort with canyon and track capability, giving you the stance, handling, and adjustability you've been chasing without compromising daily driveability.
TPU Series Technology: The TPU uses a digressive piston design that delivers firmer low-speed damping for flatter cornering and sharper response, while softening at higher shaft velocities to absorb bumps. If you want more control than a linear coilover without sacrificing ride quality, this is the set.
Every TPU set features a monotube damper with 32 levels of damping adjustment, so you can tune ride quality to match the road, the weather, or your driving mood. Full-length ride-height adjustment separates preload from ride height — meaning you can drop the IS300h to the height you want while preserving spring travel and shock stroke. Riaction coilovers for the 2014-2017 Lexus IS300h are fully rebuildable and backed by a 2-year warranty, making the TPU a long-term suspension investment rather than a disposable upgrade.
TPU Series Technology
- Monotube linear damper with seamless 52mm electroplated carbon steel body
- 32-level damping adjustment (1-Way)
- 44mm CNC-machined 6061 aluminum high-flow piston
- 20mm piston rod for MacPherson applications / 14mm for non-MacPherson
- SAE9254 cold-wound linear main springs
- Multi-thickness valving shims for consistent damping
- Polyurethane oil seals and 7.5W suspension fluid
- Low-gas-pressure design for improved compliance
- Fully rebuildable — built to be serviced, not replaced
Features
- Full-length ride-height adjustment (preload-independent)
- 32 levels of damping adjustment
- Optional Swift Springs upgrade (sold separately)
- 2-year limited warranty
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 | LX-011-SS |
| Part Name | Riaction TPU Coilovers |
| Vehicle | 2014-2017 Lexus IS300h |
| Drivetrain | RWD |
| Adjustment Type | 1-Way |
| Ride-Height Adjustable | Yes |
| Spring Rate - Front | 12 Kg/mm |
| Spring Rate - Rear | 8 Kg/mm |
| Top Mounts - Front | OEM |
| Top Mounts - Rear | OEM |
| Camber Plates - Front | No |
| Camber Plates - Rear | No |
| Suspension Design - Front | True Coilover |
| Suspension Design - Rear | Divorced |
| Notes | BALL FLM |
Vehicle Fitment
- 2014 Lexus IS300h
- 2015 Lexus IS300h
- 2016 Lexus IS300h
- 2017 Lexus IS300h