
XYZ Racing Circuit Master Coilovers — Subaru IMPREZA GDB STI D-F (PCD: 5 X 114.3) 4WD 2005-2007
SKU: SU051-CM
- IncludesFull set of 4 (front + rear)
- Spring rate (F/R)22 / 12 kg/mm
- Top mountPillow ball + rubber / Hardened rubber
Fits Subaru IMPREZA GDB STI D-F (PCD: 5 X 114.3) 4WD (2005-2007) chassis SU051
Added to basket ✓

The GDB-generation Impreza STI carries its weight low and wide, with the EJ207’s turbo bulk sitting ahead of the front axle and a centre diff sending drive to all four corners. That layout rewards a chassis that can be tuned corner by corner rather than left to a single compromise spring rate, which is exactly the gap the Circuit Master fills on the D-F-spec GDB.
For sustained circuit lap-time work – repeated sessions rather than a single fast road blast – the AWD Impreza needs damping that stays consistent as track temperature climbs and body control that doesn’t fade when the DCCD is shuffling torque mid-corner. The Circuit Master is built around that demand, giving the STI a platform that holds its line through direction changes instead of wallowing on the factory-rate springs.
What this coilover does for your 2005-2007 Subaru Impreza
With 9720 damping combinations available through the kit’s three external knobs, you can separate low-speed compression for weight transfer under braking from high-speed rebound for kerb strikes and mid-corner bumps – a genuine advantage on the nose-heavy GDB where front-end load changes fast under trail braking. Lowering the ride height also drops the centre of gravity across a car that came from the factory riding higher than its rally-bred underpinnings really need. Owners running the Impreza on track will feel less dive under braking into slower corners and sharper turn-in response as the front axle stops fighting body roll before the AWD system can put power down cleanly out the other side. Because the platform is adjustable rather than fixed, you can soften the setup for a road-and-track car or firm it right up for a car that lives on circuit.
About the Circuit Master coilover
XYZ Racing built the Circuit Master as its top-tier circuit damper, developed and run by XYZ’s own racing teams across international tracks rather than tuned on a bench alone. The headline figure is 9720 distinct adjustment combinations across the three external knobs, giving a far finer window of control than a basic two-way unit – useful when a GDB STI’s front-heavy AWD balance needs precise tuning rather than a broad-stroke setting. One quirk worth knowing: the small-bore oil passage design behind those adjustment knobs can produce a faint noise over sharp bumps or kerbs. That’s the damper doing its job, not a fault, and it’s specifically engineered around circuit-surface use rather than daily-road comfort.
Fitment for the Subaru Impreza (2005-2007)
This kit is built for the GDB-chassis Impreza STI D-F, AWD, matching the 5 x 114.3 PCD used across this generation. Confirm your STI falls within the 2005-2007 build window before ordering, as the GDB ran multiple sub-variants across its production life.
What buyers also search for
- Subaru Impreza GDB STI coilover kit for AWD track and fast-road use
- Circuit Master damping built for repeated Impreza STI lap sessions
- Adjustable coilovers for the 2005-2007 GDB STI D-F chassis
- Subaru STI suspension upgrade that controls front-end weight transfer
- 5×114.3 PCD coilover kit for GDB Impreza AWD platforms
Spec your Circuit Master to suit road-and-track or dedicated circuit use – configure yours below.
Because its 3 adjustment knobs with small oil hole design, when driving through big bumps, the coilover oil will go through small passage which might cause some small noise. This is normal situation. This product is made for circuit tracks and there will be no concern for bumps on the tracks.
Top mounts included with your kit
Every XYZ Racing coilover kit ships with the upper mounts listed below for your exact chassis — no extra parts to source.
Pillow ball + rubberP+Pillow-ball upper with a rubber insert — adds steering precision and camber adjustability while keeping some of the factory mount’s harshness damping.
Hardened rubberRHardened rubber upper — firmer than the factory bush for tighter response while retaining road-friendly noise and vibration isolation.