One of the most overlooked steps when upgrading a Subaru intercooler is fitting a correctly sized hood scoop splitter. Without it, even the best intercooler upgrade will fall short of its potential.

A larger intercooler core increases cooling surface area, but if the factory splitter remains in place it restricts airflow to the new core. Remove the splitter entirely and the problem reverses — air flows around the intercooler rather than through it, causing heat soak and rising intake air temperatures that directly reduce power.

The Process West Hood Scoop Splitter solves both problems. Designed specifically for the Process West Top Mount Intercooler and the 2001–02 WRX/STI hood scoop, it forms a complete seal around the core, forcing cooling air through the intercooler and maximising charge air cooling efficiency.

The right finish to any 2001–02 WRX/STI intercooler upgrade.

One of the most overlooked steps when upgrading a Subaru intercooler is fitting a correctly sized hood scoop splitter. Without it, even the best intercooler upgrade will fall short of its potential.

A larger intercooler core increases cooling surface area, but if the factory splitter remains in place it restricts airflow to the new core. Remove the splitter entirely and the problem reverses — air flows around the intercooler rather than through it, causing heat soak and rising intake air temperatures that directly reduce power.

The Process West Hood Scoop Splitter solves both problems. Designed specifically for the Process West Top Mount Intercooler and the 2003–05 STI hood scoop, it forms a complete seal around the core, forcing cooling air through the intercooler and maximising charge air cooling efficiency.

The right finish to any 2003–05 STI intercooler upgrade.

One of the most overlooked steps when upgrading a Subaru intercooler is fitting a correctly sized hood scoop splitter. Without it, even the best intercooler upgrade will fall short of its potential.

A larger intercooler core increases cooling surface area, but if the factory splitter remains in place it restricts airflow to the new core. Remove the splitter entirely and the problem reverses — air flows around the intercooler rather than through it, causing heat soak and rising intake air temperatures that directly reduce power.

The Process West Hood Scoop Splitter solves both problems. Designed specifically for the Process West Top Mount Intercooler and the WRX 2003–07 and STI 2006–07 hood scoop, it forms a complete seal around the core, forcing cooling air through the intercooler and maximising charge air cooling efficiency.

The right finish to any WRX or STI intercooler upgrade.

One of the most overlooked steps when upgrading a Subaru intercooler is fitting a correctly sized hood scoop splitter. Without it, even the best intercooler upgrade will fall short of its potential.

A larger intercooler core increases cooling surface area, but if the factory splitter remains in place it restricts airflow to the new core. Remove the splitter entirely and the problem reverses — air flows around the intercooler rather than through it, causing heat soak and rising intake air temperatures that directly reduce power.

The Process West Hood Scoop Splitter solves both problems. Designed specifically for the Process West Top Mount Intercooler, it forms a complete seal around the core, forcing cooling air through the intercooler and maximising charge air cooling efficiency.

The right finish to any Forester XT intercooler upgrade.

One of the most overlooked steps when upgrading a Subaru intercooler is fitting a correctly sized hood scoop splitter. Without it, even the best intercooler upgrade will fall short of its potential.

A larger intercooler core increases cooling surface area, but if the factory splitter remains in place it restricts airflow to the new core. Remove the splitter entirely and the problem reverses — air flows around the intercooler rather than through it, causing heat soak and rising intake air temperatures that directly reduce power.

The Process West Hood Scoop Splitter solves both problems. Designed specifically for the Process West Top Mount Intercooler and the stock Forester XT hood scoop, it forms a complete seal around the core, forcing cooling air through the intercooler and maximising charge air cooling efficiency.

The right finish to any Forester XT intercooler upgrade.

This Process West Hot Side Adapter Hose is specifically designed for 2008–2014 WRX owners utilizing the older generation Process West Top Mount Intercooler. It provides the necessary plumbing to adapt your intercooler system to a traditional "VF" style turbocharger.

Product Highlights

• Turbo Upgrade Compatibility: Allows for the seamless installation of traditional "VF" type turbochargers (tube-style outlets) by replacing the standard two-bolt flange arrangement.

• Legacy Fitment: Specifically engineered to match the dimensions and positioning of the older style Process West Top Mount Intercooler.

• Premium Build: Constructed from high-strength, reinforced silicone for maximum durability and heat resistance under heavy boost.

Specifications

• Vehicle Compatibility: 2008–2014 Subaru WRX.

• Required Hardware: Must be used with an Older Style Process West TMIC.

• Application: Connects a traditional "VF" style turbo outlet to the intercooler.

Note: This hose is a specialised adapter and is not compatible with the factory Subaru intercooler or the current-generation Verticooler/TMIC designs.

The Process West Hot Side Adapter Hose is designed specifically for 2008–2014 WRX owners who have upgraded to a traditional "tube-style" outlet turbocharger while running a Process West Verticooler or Top Mount Intercooler.

Product Highlights

• Turbo Conversion Support: Bridges the gap between a traditional turbocharger outlet and the Process West intercooler system.

• Heavy-Duty Construction: Made from premium, multi-layer silicone that is both heat-resistant and durable under high boost pressures.

• Specialized Fitment: Specifically tailored for the unique plumbing requirements of the Verticooler and current-style Process West Top Mount systems.

Specifications

• Compatibility: 2008–2014 Subaru WRX.

• Requirement: Must be used with a Process West Verticooler or Top Mount Intercooler.

• Turbo Fitment: Designed for traditional tube-style outlets (not compatible with the factory 2-bolt flange turbo).

Note: This hose is a specialised adapter and is not compatible with the factory Subaru intercooler.

The Process West Hot Side Intercooler Piping Kit eliminates the restrictions of the factory hot side piping, delivering a more direct and smoother airflow path between the turbo and intercooler.

The larger, higher-flow design reduces restriction across the system, resulting in improved throttle response, reduced turbo lag, and a noticeable gain in power over the factory setup.

A simple, effective upgrade for any BA/BF Falcon build.

The Process West DITTO (Direct Injection Tubular Original) represents the pinnacle of intake engineering for the FA20DIT platform. By combining a precision billet plenum with high-flow, large-bore cast runners, the DITTO manifold delivers the highest intake flow rates currently available for the VA WRX.

Engineering & Performance

Developed over 12 months of rigorous in-house R&D, the DITTO manifold is designed to optimize cylinder filling through increased plenum volume and computer-tested internal porting.

• No Tune Required: As part of our ‘NO CEL’ range, this manifold can be installed on a completely stock vehicle without triggering a Check Engine Light or requiring a custom map.

• Proven Gains: Performance increases are immediate and measurable even on standard vehicles, with gains scaling significantly as power levels increase on tuned applications.

• Build Quality: A premium hybrid construction utilizing billet and cast aluminum for maximum strength under high boost.

Versatility & Fitment

The DITTO is designed as a direct-fit solution for vehicles already equipped with Process West cooling systems, though it is compatible with a wide range of setups.

• Front Mount Intercoolers: Direct fit for all kits that utilize the stock inlet manifold.

• Process West Verticooler: Requires fitting kit (Part Number: PWIM007VFT).

• Other TMICs: The Khanacooler and other aftermarket top-mounts may require minor modifications to mounting brackets and under-hood ducting.

DITTO RACE: The 1000+ HP Solution

For high-horsepower builds, we offer the DITTO RACE version. This variant includes four additional injector ports designed to house any EV-14 specification fuel injector.

This provides tuners the flexibility to supplement the factory direct injection with port injection, delivering the fuel volume necessary to support 1000+ hp builds. While Process West provides the manifold functionality and hardware, an aftermarket ECU or injector driver is required to manage the secondary fuel system.

Note: For maximum results, we recommend pairing the DITTO manifold with high-flow charge pipes and optimised intercooler setups.

Designed for the MY22+ FA24 WRX, the Process West Intake Manifold comprises of a mix of billet plenum, cast large bore runners along with a fully operational billet Tumble Generator Valve (TGV) section to achieve the highest intake flow rates possible.

Process West is the first to develop an Intake Manifold for the FA24.

After over 12 months of development and testing on the in-house WRX, Process West have engineered a product that delivers proven performance gains with flawless fitment.

Power improvements are achieved through precision computer-designed internal porting, increased plenum volume, and larger runner capacity — optimising airflow for maximum cylinder filling and engine performance.

Even greater performance gains can be achieved on tuned FA24 engines. Testing by Process West shows that the higher the power output, the greater the gain!

Performance Gains

The Process West in-house WRX featured the typical modification you’d expect before adding an intake manifold:

• Process West stage 2 intercooler
• Process West air intake
• Invidia Turbo back exhaust
• Blouch 5056 bolt on turbo
• Stock intake manifold
• 98 fuel (US 93 spec)

Without the Manifold the vehicle produced 246KW (331 HP) at the wheels (it’s worth noting that at stock standard the VB WRX makes 197whp on this dyno). We then bolted the Process West Manifold on, adjusted the tune with the same boost pressure as we did initially (yes, the lower restriction on our manifold will drop you a PSI or so of boost, it works that well) before turning out an impressive 275kw (368hp) at all four.

Not only is that an overall improvement of 12% in total power - with gains ACROSS the rev range, there was also a solid 10% additional torque that is on offer most of the way from 2500rpm through to 6500rpm.

Why Process West Included The TGV Section.

The Process West FA24 Intake Manifold includes a fully integrated TGV section, as the factory manifold is a one-piece design with a non-removable TGV system.

Designing a standalone intake manifold was not possible without also re-engineering the TGV system.

As a result, Process West developed a complete billet intake manifold featuring a fully functional TGV section with operational shafts and butterflies.

TGV Delete.

For customers seeking a full TGV delete, we also offer components that allow complete removal of the TGV shafts and butterflies while retaining the factory drive motors and sensors, ensuring the ECU remains free of Check Engine Lights.

The solution provided by Process West is the only proven method for achieving a true TGV delete on the FA24 platform.

All manifolds delivered to the USA will have the TGV shafts and butterflies installed. If you would like to run “TGV delete” style contact Process West directly for the parts to do the conversion. Ask for part number PWTD07.

No Check Engine Light.

The Process West FA24 intake manifold not only delivers performance enhancements but is also part of the Process West 'NO CEL' range, ensuring easy installation without triggering a Check Engine Light.

Application And Compatibility.

The Process West FA24 Intake Manifold installs easily with no custom fabrication required.

Please note, it must be used with a front-mounted intercooler, as the new throttle body position is lower and closer to the firewall than the factory design, making top-mounted intercoolers incompatible.

This new throttle body position also means many front-mount kits will not be compatible without the Process West Throttle Adaptor Pipe (PWIM010AP). If you currently have a Process West Front Mount Intercooler Kit, this adaptor pipe is also required, as the piping route of the original kit will not align with the new throttle body position.

For those with alternative aftermarket front mount intercoolers, this adaptor pipe includes multiple hose joint options, giving you more flexibility for an easy fitment.

Port Injection Version (PWIM010PI).

For Hardcore WRX Tuners, Process West provides a race version with an additional 4 port injector mounts.

In continuing Process West tradition we guarantee this will be a great investment to the performance pedigree of your VB WRX.

The Process West Billet Intake Manifold for the 2001–05 WRX and STI is the product of an exhaustive development process: years of research, multiple prototype iterations, and a design philosophy that refuses to compromise between performance and build quality.

Construction that speaks for itself.

Machined from solid billet aluminium with generous bell-mouth runner entries, thick-wall polished CNC mandrel bent tube components, and high-end TIG welding throughout, this manifold is built to a standard that cast and fabricated alternatives simply cannot reach. Rated to 100psi of boost pressure, it is equally at home on an aggressive street build as it is on a full-spec drag car.

Proven performance.

The plenum volume and runner length combination is tuned specifically for the Track configuration, optimised for strong low and mid-range torque with aggressive top-end power delivery. On stock setups, gains of 10% or more have been recorded. On highly modified builds, the same level of improvement holds. For builds requiring even more top-end power, shorter billet TGVs are available.

Reverse throttle body orientation.

Designed for 2001–05 WRX and STI builds where the standard throttle body position is not compatible with the chosen intake or engine bay layout. Custom throttle flanges are available on request for further specialised fitment requirements.

The Track manifold is recommended for any performance build not requiring air conditioning, from serious street cars to dedicated circuit and drag applications.

Intake Manifold — Cable Throttle, Reverse Orientation, Subaru WRX/STI 1999–00

The Process West Billet Intake Manifold is the result of years of research, multiple prototype iterations, and an uncompromising design process. It represents the highest level of induction engineering available for the Subaru WRX and STI, where precision aesthetics and outright performance are equally non-negotiable.

Billet construction throughout.

The manifold features a full billet plenum with generous billet bell mouths and thick-wall polished CNC mandrel bent tube components, assembled with high-end TIG welding. This construction makes it suitable for boosted applications up to 100psi, a specification no other product in this category comes close to matching in terms of strength and finish quality.

Engineered for real performance gains.

The plenum volume and runner length combination has been optimised for strong low and mid-range torque without sacrificing top-end power. Even on a stock setup, customers regularly see gains of 10% or more. The performance advantage over competing aftermarket intake manifolds is significant enough that customers have removed other systems to fit the Process West unit.

Reverse orientation, cable throttle.

This configuration features a reverse orientation throttle body position with cable throttle actuation, making it suited to the 1999–00 GC8 WRX and STI and specific intake setups where the standard orientation is not practical. Custom throttle flanges are available on request for specialised applications.

Broad compatibility.

The range is modular, covering everything from the MY99 GC8 through to the latest WRX and STI models. For performance builds not requiring air conditioning, the Track version manifold is recommended and can be supplied with shorter billet TGVs for increased power in the upper rev range.

The pinnacle of induction for the Subaru WRX and STI.

For the 2001–05 WRX and STI owner who wants the highest level of induction performance without giving up daily usability, the Process West Street Billet Intake Manifold is the answer.

This is not a compromise product. It is the result of years of research, multiple prototypes, and a ground-up design process that has made it one of the most respected intake manifolds in the Subaru performance market.

Built without limits.

Every component is CNC machined from solid billet aluminium, featuring generous bell-mouth runner entries and thick-wall polished mandrel bent tube components assembled with high-end TIG welding. The result is a manifold rated to 100psi of boost pressure, a level of structural integrity that no cast or fabricated alternative can match.

Street performance, without sacrifice.

The plenum volume and runner length of the Street version are specifically tuned for strong low and mid-range torque while still opening up power higher in the rev range. Critically, the plenum volume remains compatible with the factory air conditioning system, making this the right choice for any build that needs to remain comfortable and streetable day to day.

Testing on completely stock engine, turbo, and fuel system setups has shown approximately 9% gains in both torque and power. The same percentage gain has been recorded on highly modified setups running E85, demonstrating the manifold's capability across a wide range of build levels.

For builds requiring more top-end power, the Street version can be supplied with shorter billet TGVs. Custom throttle flanges are available on request.

The street manifold that does not ask you to compromise.

For the 1999–00 GC8 WRX and STI owner who wants the highest level of induction performance without giving up daily usability, the Process West Street Billet Intake Manifold is the answer.

This is not a compromise product. It is the result of years of research, multiple prototypes, and a ground-up design process that has made it one of the most respected intake manifolds in the Subaru performance market.

Built without limits.

Every component is CNC machined from solid billet aluminium, featuring generous bell-mouth runner entries and thick-wall polished mandrel bent tube components assembled with high-end TIG welding. The result is a manifold rated to 100psi of boost pressure — a level of structural integrity that no cast or fabricated alternative can match.

Street performance, without sacrifice.

The plenum volume and runner length of the Street version are specifically tuned for strong low and mid-range torque while still opening up power higher in the rev range. Critically, the plenum volume remains compatible with the factory air conditioning system, making this the right choice for any build that needs to remain comfortable and streetable day to day.

Testing on completely stock engine, turbo, and fuel system setups has shown approximately 9% gains in both torque and power. The same percentage gain has been recorded on highly modified setups running E85, demonstrating the manifold's capability across a wide range of build levels.

For builds requiring more top-end power, the Street version can be supplied with shorter billet TGVs. Custom throttle flanges are available on request.

The street manifold that does not ask you to compromise.

Intake Manifold — DBW Reverse Orientation, Subaru WRX/STI 2006–21

When the standard throttle body position does not suit your build, the Process West Track Billet Intake Manifold in reverse orientation delivers the same uncompromising performance in a configuration that works for more demanding engine bay layouts.

Built for serious applications.

CNC machined from solid billet aluminium throughout, with generous bell-mouth runner entries, thick-wall polished mandrel bent tube components, and high-end TIG welding. Rated to 100psi of boost pressure and finished to a standard that no cast or fabricated manifold can match. This is a component built to perform at the highest level and look the part doing it.

Track-tuned performance.

The Track version plenum volume and runner length are optimised for aggressive torque delivery low and mid in the rev range, with strong top-end power to match. Gains of 10% or more have been recorded on completely stock setups, and customers regularly remove competing aftermarket manifolds to fit the Process West unit once they understand the difference in real-world performance.

This configuration is recommended for any performance build not requiring air conditioning, from hard street and circuit cars through to full drag applications. For builds chasing maximum top-end power, shorter billet TGVs are available to further optimise the runner length. Custom throttle flanges are available on request.

Covers the 2006 GD through to the 2021 VA WRX and STI.

Covering the 2006 GD through to the 2021 VA WRX and STI, the Process West Street Billet Intake Manifold is the result of years of research, multiple prototype iterations, and a design process that has produced one of the most capable and well-regarded induction upgrades in the Subaru performance market.

Built to a higher standard.

Every component is CNC machined from solid billet aluminium. Generous bell-mouth runner entries, thick-wall polished mandrel bent tube components, and high-end TIG welding combine to produce a manifold rated to 100psi of boost pressure. It is a level of construction that cast and fabricated alternatives cannot replicate, in strength, precision, or finish.

Real gains, across all build levels.

On stock engine, turbo, and fuel system setups, testing has recorded approximately 9% gains in both torque and power. On heavily modified builds running E85, the same level of improvement holds. The plenum volume and runner length are tuned for strong low and mid-range torque with continued power delivery through the upper rev range — and unlike many performance manifolds, the plenum remains fully compatible with the factory air conditioning system.

For any street build that needs to perform hard without sacrificing comfort, this is the correct solution. For builds requiring more top-end power, shorter billet TGVs are available. Custom throttle flanges are available on request.

The street manifold built to last, perform, and impress at every level of modification.

The Process West Billet Intake Manifold is the result of years of research, multiple prototype iterations, and an uncompromising design process. It represents the highest level of induction engineering available for the Subaru WRX and STI, where precision aesthetics and outright performance are equally non-negotiable.

Billet construction throughout.

The manifold features a full billet plenum with generous billet bell mouths and thick-wall polished CNC mandrel bent tube components, assembled with high-end TIG welding. This construction makes it suitable for boosted applications up to 100psi, a specification no other product in this category comes close to matching in terms of strength and finish quality.

Engineered for real performance gains.

The plenum volume and runner length combination has been optimised for strong low and mid-range torque without sacrificing top-end power. Even on a stock setup, customers regularly see gains of 10% or more. The performance advantage over competing aftermarket intake manifolds is significant enough that customers have removed other systems to fit the Process West unit.

Reverse throttle body orientation.

This configuration features a reverse orientation throttle body position, making it suited to specific intake and engine bay setups where the standard orientation is not practical. The Bosch drive-by-wire 74mm throttle body fitment delivers precise throttle control at all power levels. Custom throttle flanges are available on request for specialised applications.

Broad compatibility.

The range is modular, covering everything from the MY99 GC8 through to the latest WRX and STI models. For performance builds not requiring air conditioning, the Track version manifold is recommended and can be supplied with shorter billet TGVs for increased power in the upper rev range.

The pinnacle of induction for the Subaru WRX and STI.

The Process West Billet Intake Manifold is the result of years of research, multiple prototype iterations, and an uncompromising design process. It represents the highest level of induction engineering available for the Subaru WRX and STI, where precision aesthetics and outright performance are equally non-negotiable.

Billet construction throughout.

The manifold features a full billet plenum with generous billet bell mouths and thick-wall polished CNC mandrel bent tube components, assembled with high-end TIG welding. This construction makes it suitable for boosted applications up to 100psi, a specification no other product in this category comes close to matching in terms of strength and finish quality.

Engineered for real performance gains.

The plenum volume and runner length combination has been optimised for strong low and mid-range torque without sacrificing top-end power. Even on a stock setup, customers regularly see gains of 10% or more. The performance advantage over competing aftermarket intake manifolds is significant enough that customers have removed other systems to fit the Process West unit.

Broad compatibility.

The range is modular, covering everything from the MY99 GC8 through to the latest WRX and STI models. This configuration suits stock throttle body fitment with the Bosch drive-by-wire 74mm throttle body. Custom throttle flanges are available on request for specialised applications.

For performance builds not requiring air conditioning, the Track version manifold is recommended and can be supplied with shorter billet TGVs for increased power in the upper rev range.

The pinnacle of induction for the Subaru WRX and STI.

The DITTO RACE (Direct Injection Tubular Original) is the ultimate intake solution for high-horsepower 2015-2021 Subaru WRX builds. While the standard DITTO manifold revolutionizes airflow, the RACE version is specifically engineered for tuners and racers who have pushed the factory direct injection system to its absolute limit.

Integrated Port Injection

The standout feature of the DITTO RACE is the inclusion of four additional port injector mounts and high-flow fuel rails. This hybrid fueling capability allows you to transcend the limitations of the factory DI system.

• 1000+ HP Capacity: Designed to house any EV-14 specification fuel injector, providing the fuel volume necessary for elite-level power figures.

• Tuning Flexibility: Gives tuners the ability to supplement fueling via an aftermarket ECU or injector driver, ensuring safe and consistent AFRs under extreme boost.

• Future-Proof: Even if you aren't at 1000hp yet, the RACE manifold provides the infrastructure to grow without needing to replace your intake manifold twice.

Performance & Flow Engineering

At its core, the DITTO RACE utilizes a precision-engineered billet plenum mated to large-bore cast runners.

• Optimised Cylinder Filling: Computer-designed internal porting and increased plenum volume ensure maximum air delivery to every cylinder.

• Measurable Gains: Developed over 12 months of in-house R&D, this manifold provides immediate power and torque improvements that scale upward as you increase boost.

• ‘NO CEL’ Compatibility: Despite its racing pedigree, the manifold is designed to operate on a standard vehicle without triggering a Check Engine Light.

Application & Fitment Notes

The DITTO RACE is a direct-fit solution for most intercooler configurations, though some setups require specific hardware:

• Process West Verticooler: Requires fitting kit (Part Number: PWIM007VFT).

• Front Mount Intercoolers: Direct fit for all kits currently using the stock inlet manifold.

• Top Mount Intercoolers: The Khanacooler and other aftermarket TMICs may require minor modifications to mounting brackets and under-hood ducting.

Note: While Process West provides the manifold and fuel rail hardware, secondary injectors and the electronic management hardware (ECU/Driver) must be sourced separately.

ISUZU DMAX Optional Piping Kit

Your Process West Intercooler kit comes with the two hoses that go behind the grille, and not the engine bay hoses as they differ between DPF and non-DPF versions of the Isuzu DMAX.

To complete your installation (although these parts are not mandatory) you can order the matching high quality Process West silicone hoses to suit your particular model.

ISUZU DMAX – Non-DPF Version