2015-2021 Subaru STI Engine

The long-awaited GrimmSpeed Bypass Valves are here! Our passion for building the most robust, best-performing parts on the market has driven us to ...

This kit is designed to provide a way to data log and monitor the ethanol content of fuel on most new Subaru Vehicles. Our proprietary controller r...

The GrimmSpeed Alternator/Pulley Covers, Fender Shrouds and Radiator Shrouds are NOW available in our all new neon green color option, both individ...

At GrimmSpeed we know that not everyone is ready for one of our full aftermarket intake systems, but still wants a safe and easy way to increase po...

The PERRIN High Flow Washable Replacement Air Filter is the last filter you will ever need to buy. Not only is it washable, but it will increase ho...

6A1 540 A * Type 1 Aluminum Oval shape * Steel Blue Bracket Light weight aluminum oval shaft, strong & durable.

This kit is designed to provide a way to data log and monitor the ethanol content of fuel on most new Subaru Vehicles. Our proprietary controller r...

 Industry first (and patent pending) DOHC EJ Cylinder 4 Combustion Chamber Cooling kit increases coolant flow in the LH head to improve reliability...

Adding a well-design, well-built aftermarket up pipe is one of the first things you should do to your Subaru. Our ultimate goal was to make the bes...

You've been asking for this bad sally for a while and it's finally here. The intake the for the 15+ STI can be thought of as a hybrid of the tube a...

Performance During cornering, the Perrin Strut Tower Brace improves chassis rigidity, enhances steering precision under high load conditions, and r...

The IAG Performance PTFE Engine Bay Flex Fuel Kit for the 2008-21 Subaru STI combines our popular PTFE Flex Fuel Line kit with IAG Top Feed Fuel Ra...

The IAG Performance V3 Street Series Air / Oil separator (AOS) is an excellent investment to keep your Subaru vehicle running well. The Street Seri...

Add a little style to your hood struts by swapping them for these carbon fiber topped ones. Same OE style reliability with improved looks. Each gas...

Proudly made in the USA - Design, Materials and Fabrication Innovative 3-D Contour Flange (Limited models only) FARO™ Arm Designed - We are at ...

An oil filler cap that combines a resin cover with an aluminum base cap that has been die-cast and cut. The shape of the cap is carefully designed ...

This is the Invidia Equal Length Big Piping Exhaust Manifold. This type of manifold is ideal for those of you looking to surpass large horsepower f...

At GrimmSpeed™ we have worked with endless amounts of aftermarket gaskets, none seem to work as well as the multi-layer steel OEM style gaskets. Th...

Constructed with 100% polyurethane on all four sides, this high flow, oiled OE replacement performance filter will out flow stock paper filter for ...

The pitch stop is designed to reduce front to back engine movement under acceleration and braking. In order to achieve maximum comfort, the factory...

The PERRIN Electronic Boost Control Solenoid (EBCS) Pro is designed to control today's high performance turbochargers with its ultra-fast response ...

6A1 561 ALHD * USDM / LHD application * Steel Blue Bracket Upon hard braking, the sheet metal of the firewall flexes immensely from hydraulic press...

Steel * Bolt on installation * Only for 6 Speed MT Protect Inner joint grease from high heat from muffler front pipe.

* Steel * Bolt on installation * Only for 6 Speed MT Protect Inner joint grease from high heat from muffler front pipe. 6A1 047 F

Here are the details: 1050Xcc Injector model Compact body Improved internal flow path increases output by 5% without sacrificing low flow performan...

50 State Legal Simple ECU flashing with gauge package! The new in-cabin mountable Accessport V3 has a large, full color, higher resolution screen ...

IAG 550 EJ25 2.5L SUBARU SHORT BLOCK DESIGNED FOR STRENGTH The IAG 550 Short Block is designed for modified EJ25 Subarus that n...

Description The blades that promote even temperatures and airflow through your engine bay, while giving your Subaru an outstanding visual upgrade....

The Killer B Motorsport Holy Header VE-Max was developed using state of the art CAD software, simulations, and testing, to determine optimal high p...

The Killer B Motorsport Holy Header VE-Max was developed using state of the art CAD software, simulations, and testing, to determine optimal high p...

For those wanting nothing but the best, the Beatrush Titanium front strut bar delivers just that.  Weighing a mere 1.2kg or 2.6lbs, not only are yo...

The IAG Competition Series Oil Pan for the Subaru WRX and STI is uniquely designed and CNC machined to suit a wide range of street and track applic...

The IAG Competition Series Oil Pan for the Subaru WRX and STI is uniquely designed and CNC machined to suit a wide range of street and track applic...

The IAG Street Series Oil Pan for the Subaru WRX and STI is uniquely designed and CNC machined to suit a wide range of street and track application...

The IAG Unequal Length Headers are the perfect way to add more performance to your Subaru WRX STI and still keep the iconic "Boxer Rumble." The hea...