The GrimmSpeed 04-21 Subaru STI EJ25 2-Bolt Up-Pipe is designed for the 2004-2021 Subaru WRX STI. Match manufacturer part number GRM.1099.1.SS, the complete vehicle or system configuration, dimensions, connections, and included components before ordering.
Key Features
- Increased Exhaust Flow – Larger diameter and smoother bends improve overall exhaust efficiency.
- T304 Stainless Steel Construction – Premium material for excellent strength and corrosion resistance.
- Direct Bolt-On Fitment – Precision engineered for 2004–2021 Subaru STI EJ25 engines.
- Precision-machined and tested components trusted by Subaru enthusiasts worldwide.
- A: Yes. The larger diameter and smoother design significantly reduces turbo lag compared to the factory up-pipe.
- A: Yes. It uses the factory 2-bolt flange and includes all necessary gaskets and hardware.
Fitment
| Years | Make | Model | Application |
|---|---|---|---|
| 2004-2021 | Subaru | WRX STI | Confirm engine, body style, system configuration, and exact interface |
Specifications
| Brand | GrimmSpeed |
|---|---|
| Manufacturer Part Number | GRM.1099.1.SS |
| Product Type | Connecting Pipes |
| Fitment Type | Vehicle Specific |
| Condition | New |
| Type | 2-Bolt Up-Pipe |
| Engine | Subaru EJ25 |
| Material | T304 Stainless Steel |
| Design | 2-Bolt Flange |
| Country of Origin | United States |
| Warranty | GrimmSpeed Limited Warranty |
What's Included
One new GrimmSpeed connecting pipes identified by manufacturer part number GRM.1099.1.SS, in the quantity stated by the title. Additional wiring, pipes, hoses, clamps, fittings, gaskets, fluids, tuning, tools, and installation hardware are included only when expressly listed for this exact part number.
About GrimmSpeed
GrimmSpeed develops exhaust, forced-induction, cooling, engine, electronics, and exterior components for import and performance vehicle applications.
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Frequently Asked Questions
How do I confirm this GrimmSpeed exhaust part fits?
Match the manufacturer part number, listed year, make, and model, body style, engine, exhaust diameter, flange locations, and available underbody clearance.
Does this listing include every part needed for installation?
Only the items stated in the title and What’s Included section are supplied. Gaskets, adapters, hardware, hangers, or connecting pipes may be separate for some applications.
Will the exhaust change sound or require tuning?
Sound varies with the complete exhaust system and vehicle. Tuning requirements depend on the application, emissions equipment, and other modifications, so confirm with the vehicle tuner before installation.
Installation Instructions
Follow the current GrimmSpeed instructions and the vehicle service manual for part number GRM.1099.1.SS. Compare every component, connection, dimension, and mounting point before disassembly. Use the correct tools, fasteners, torque values, fluids, wiring protection, and safety procedures, then inspect for leaks, interference, heat exposure, clearance, and secure operation before normal use.
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