How reliable is this fitment answer?

Confidence: Limited (1 of 3). Forum, Reddit or anecdotal report, or ambiguous/partial detail. Treat as a lead to research. Based on 2 cited source(s), last verified 2026-10-26.

Will OEM 2008-17 STI Brembo 4-piston front calipers (326 mm rotor) fit a Subaru WRX (GD/GG, 2002-2007)?

Q: Will OEM 2008-17 STI Brembo 4-piston front calipers (326 mm rotor) fit a Subaru WRX (GD/GG, 2002-2007)?

Yes, with extra parts or work. Fits with 5x100 rotors, per one retailer: most 2002+ Impreza share the STI front caliper mounting, so 2008+ black STI front Brembos bolt to a GD WRX with STI-size rotors drilled 5x100 (2004 STI rotors were factory 5x100). Needs a wheel of at least 17 inches with spoke clearance, so the 2002-04 16-inch wheels are out.

Added 2026-10-26 · Updated 2026-10-26

Short answer: Yes, with extra parts or work Limited

Verdict:Fits with mods Limited confidence (1 of 3) · 2 sources

Yes, with extra parts or work: Fits with 5x100 rotors, per one retailer: most 2002+ Impreza share the STI front caliper mounting, so 2008+ black STI front Brembos bolt to a GD WRX with STI-size rotors drilled 5x100 (2004 STI rotors were factory 5x100).

Years: 2002-2007 · Applies to: all WRX; 17-inch or larger wheels · 2 sources · Last verified 2026-10-26

Safety-critical part. This claim comes from community or vendor sources, not the vehicle or part manufacturer, so its confidence is capped at "Reported". Have the work done or checked by a qualified professional and confirm part numbers with the manufacturer.

Part	OEM 2008-17 STI Brembo 4-piston front calipers (326 mm rotor)
Part comes from	Subaru WRX and STI (GE/GH/GR/GV, 2008-2014)
Vehicle	Subaru WRX (GD/GG, 2002-2007)
Years	2002-2007
Trim / condition	all WRX; 17-inch or larger wheels
Verdict	Fits with mods Fits with extra parts or work
Confidence	Limited 1 of 3 — Forum, Reddit or anecdotal report, or ambiguous/partial detail. Treat as a lead to research.
Last verified	2026-10-26 (date the cited sources were last read)

Details

Fits with 5x100 rotors, per one retailer: most 2002+ Impreza share the STI front caliper mounting, so 2008+ black STI front Brembos bolt to a GD WRX with STI-size rotors drilled 5x100 (2004 STI rotors were factory 5x100). Needs a wheel of at least 17 inches with spoke clearance, so the 2002-04 16-inch wheels are out.

Specs

pistons mm: 40 x2 + 46 x2
rotor mm: 326 x 30 ventilated
wheel class: 17-inch type
pad mm: 131.8 x 60.5 x 8.9 (2012 manual)

Other brakes fitment for the GD

2004-2007 STI front Brembo calipers — Unclear — details missing Unclear
2004-2007 STI rear Brembo calipers — Fits with extra parts or work Fits with mods
DBA 2657 rear adapter rotor — Reported to fit Fits
Subaru Legacy GT brakes — Fits with extra parts or work Fits with mods

This part on other generations

Subaru WRX and STI (GE/GH/GR/GV, 2008-2014) — Fits with extra parts or work Fits with mods
Subaru WRX and STI (VA, 2015-2021) — Fits with extra parts or work Fits with mods

More for this car

All Subaru WRX (GD/GG, 2002-2007) fitment answers · GD common problems
Guide: WRX GD bolt pattern: 5x100 vs 5x114.3 (2002-07 WRX and STI)
Guide: 2002-05 WRX vs 2006-07 WRX: EJ205 vs EJ255, known problems and wheels
Newsletter archive: past issues with every new and corrected entry

Sources

STi Brembo Brakes — FastWRX.com (Mach V Motorsports, Subaru parts retailer) (vendor article; read 2026-10-26; full page read)
Most 2002+ Impreza share the front mount; only 2004 STI rotors are 5x100; 17-inch minimum.
Subaru Four-Pot/Two-Pot Brakes — FastWRX / Mach V Motorsports (parts retailer) (vendor article; read 2026-10-26; full page read)
US WRX had sliding calipers except 2006-07 four-piston cars.

Summaries are in our own words. Fitment is not guaranteed — disclaimer.

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