GrimmSpeed GRM.1099.1.SS SS 2-Bolt Up-Pipe for Subaru WRX STI Forester EJ25

Vehicle Fitment

• 2004-2021 Subaru STI (GD/GR/GV/VA), EJ257, Turbocharged, AWD
• 2006-2014 Subaru WRX (GD/GR/GH/GE/VA), EJ255, Turbocharged, AWD
• 2006-2013 Subaru Forester XT (SG/SH), EJ255, Turbocharged, AWD
• 2007-2009 Subaru Legacy GT (BP/BL), EJ255, Turbocharged, AWD
• 2007-2009 Subaru Outback XT (BP), EJ255, Turbocharged, AWD

Fitment Notes

• Designed for USDM Subaru EJ25 engines with OEM-style 2-bolt header configuration only
• Not compatible with JDM EJ20-equipped models or non-turbo EJ25 variants
• No tune required for installation - bolt-on upgrade compatible with OEM engine management
• SEMA Certified: SC-GRM01-0145 for listed fitments
• CARB Certified: EO #D-896 for listed fitments - legal for use in California on covered vehicles
• Cannot be shipped to Colorado due to state catalytic converter regulations

Features

• ½" CNC-milled 304 stainless steel flanges for precise, leak-free OEM-header-compatible fitment
• 14-gauge 304 stainless steel tubing - 33% thicker than most competitor up-pipes for added durability
• 321 stainless steel "Tuned-Bellow" interlocking flex joint positioned away from bends to extend service life
• Pipe-to-flange connection ported flush for smooth, uninterrupted exhaust flow
• Larger diameter tubing reduces exhaust restriction and improves turbo spool response
• Developed in-house using FARO Arm scanning and SolidWorks CAD for reverse-engineered OEM-level fitment accuracy
• Raw stainless steel finish (black ceramic thermal-coated version available separately as GRM.1099.1.BLK)
• GrimmSpeed Limited Lifetime Warranty - covers manufacturing defects in materials and workmanship

Specifications

• Part Number: GRM.1099.1.SS
• Type: 2-Bolt Stainless Steel Up-Pipe - Raw Stainless Finish
• Tubing Material: 304 Stainless Steel, 14 Gauge (2.0mm)
• Flange Material: 304 Stainless Steel, ½" CNC Milled
• Flex Joint Material: 321 Stainless Steel Interlocking Bellow
• Inlet Diameter: 1.93"
• Outlet Diameter: 1.72"
• Header Configuration: OEM 2-Bolt
• Certification: SEMA SC-GRM01-0145 / CARB EO #D-896
• Finish: Raw Stainless Steel
• Warranty: Limited Lifetime

Included Components

• 1x GrimmSpeed 2-Bolt Stainless Steel Up-Pipe
• GrimmSpeed Fire Ring Multi-Layer Steel Gaskets
• Zinc-Coated Corrosion-Resistant Installation Hardware

Product Description

The GrimmSpeed GRM.1099.1.SS is a SEMA Certified and CARB-approved 2-bolt stainless steel up-pipe engineered for USDM Subaru EJ25 turbocharged engines. Developed entirely in-house using FARO Arm scanning and SolidWorks CAD, the up-pipe is reverse-engineered to match OEM 2-bolt header dimensions with dead-on fitment accuracy. The larger diameter 14-gauge 304 stainless tubing reduces exhaust restriction and improves turbo spool compared to the factory restrictive up-pipe, with potential gains of up to +10 WHP depending on the build.

The 321 stainless "Tuned-Bellow" flex joint is positioned away from bends to maximize its service life, and the ported flush pipe-to-flange connection ensures smooth, uninterrupted flow from header to turbo inlet. The kit ships complete with GrimmSpeed Fire Ring multi-layer steel gaskets and zinc-coated hardware - everything needed for a clean, no-hassle installation with no tune required.