Riaction TPU Coilovers for 2021+ BMW M4 RWD (G82)

Product Details

These Riaction TPU G82 M4 coilovers fit the 2021+ BMW M4 RWD (G82).

Traction Plus Ultra (TPU) is Riaction's digressive-valved coilover. Part number 0BM-088-TPU is the kit for the rear-wheel-drive M4, and the all-wheel-drive M4 xDrive takes a different kit, 0BM-092-TPU. Digressive pistons give more damping force at low shaft speeds for body control under braking and cornering, and less at high shaft speeds over sharp bumps. The kit has 32 levels of damping adjustment, full-length ride-height adjustment, nickel-coated shock bodies and a hex-screw preload collar lock. It is fully rebuildable and carries Riaction's 2-year warranty against manufacturing defects.

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