STAGE 3 INTERCOOLER CORE
The Process West Stage 3 Front Mount Intercooler Core for the Ford BA/BF Falcon includes a 500 x 425 x 100mm bar & plate core, which is the largest and most efficient intercooler for the BA/BF Falcon on the market today. This allows for smooth flow and effective cooling of the charge air entering the engine.

The intercooler core is available in both black powdercoated or silver finish

PLENUM CHAMBER
The Process West Plenum of the BA/BF Falcon is CNC Machined to precision from solid billets of 5083 aluminium plate. Billet aluminium is super strong and holds enormous amounts of pressure, nothing but the best for Process West. To promote perfect air flow into the cylinder head each runner entry has a blended bell-mouth. The plenum is supplied with a plug-in throttle body extension wiring loom to allow for installation with no wire cutting, as well as teh option for custom cover plates.

BATTERY RELOCATION KIT
The Process West battery relocation kit has been developed to move the existing battery from the factory position to give clearance for large air box installations.

Our unique system re-locates the existing battery, mounting it behind the factory foglight area on the drivers side of the car. The reason this position was chosen was to keep the battery cables as short as possible, as long cables cause high voltage drop and poor starting performance.

The installation of the system is very simple and does not require cutting of any cables. You simply install the new laser cut battery tray and bracket, and mount the new plastic battery terminal distribution block (high density P7000) then connect the cables.

The method of extending the battery cables means no cutting and still gives easy access for jump starting/charging if needed.

4 INCH RACE AIR BOX
Our 4in race air box system has been designed for extreme power levels. Utilizing the area normally occupied by the battery we have been able to design the ultimate high horse power intake.

The air box uses a massive 6in internal diameter K&N filter which mounts onto a 6in to 4in bell mouth which connects to a internally wire re-enforced molded silicon hose down to the turbo. This combination gives maximum flow for power levels of 500rwkW+.

The air box can also be used for high mount turbo configurations. The 4in OD air box outlet is at the approximate height of most high mount turbo compressor inlets so a simple section of pipe is all that is needed to use the air box for high mounts.

For those that have upgraded their turbo to a 4in inlet (0.7A/R cover) we offer a 4in to 4in silicon hose. (PWBACAI03-hose)

This hose simplifies the installation of larger turbos. The hose can be purchased separately or part of an initial air box purchase.

For those chasing extreme power levels, the Process West Stage 4 is the next step up from our market-leading Stage 3 core, and the largest, most efficient intercooler core available for the FG Falcon.

Core specifications.
At 500 x 425 x 152mm, this bar and plate core is built for serious power. 3.5-inch inlet and outlets ensure maximum flow at high boost levels.

Retains air conditioning.
The air conditioning condenser is fully retained, and a replacement front reinforcement bar is included with the core-only option.

The definitive intercooler upgrade for high-powered FG Falcon builds.

For the Ford FG Falcon enthusiast chasing extreme power figures, thermal management is the ultimate hurdle. While our Stage 3 core has long been a market leader, the Stage 4 Intercooler Kit is pushes the boundary further. 

This is our most aggressive cooling solution, designed specifically for those looking to extract the absolute highest output from the FG platform.

The Ultimate Core

The Stage 4 kit features the largest and most efficient core we have ever offered for the FG Falcon. Built with a high-performance bar and plate design, it offers a level of thermal mass and surface area that is unmatched in the market.

Dimensions: 500 x 425 x 152mm 

Thickness

At a substantial 6 inches deep, this core provides incredible cooling volume, ensuring stable intake air temperatures even under extreme boost pressures and prolonged high-load sessions.

Large-Bore Efficiency

To accommodate the massive volume of air required for elite power levels, the core features 3.5-inch inlets and outlets, minimizing backpressure and maximizing flow.

High-Flow Piping System

To match the capabilities of the Stage 4 core, we have developed a high-volume induction path that eliminates the restrictions found in smaller systems.

3.5-inch Cold Side Piping

This oversized piping ensures that the cooled, dense air has a clear, unrestricted path to the engine, supporting maximum throttle response and top-end power.

3.0-inch Hot Side Piping

Optimised to maintain high air velocity from the turbocharger while providing the flow capacity needed for high-kilowatt builds.

Mandrel-Bent Aluminium

Every pipe is mandrel-bent to maintain a constant internal diameter, ensuring smooth, laminar airflow throughout the entire system.

Professional Hardware and Fitment

This is a complete, high-end hardware package designed for reliability under the most demanding conditions.

Silicone Joiners

The kit includes heavy-duty, multi-ply silicone connectors engineered to withstand high temperatures and extreme boost levels without expansion or leaking.

Stainless Steel Clamps

We provide premium stainless steel hose clamps to ensure a permanent, corrosion-resistant seal across all connections.

End Tanks

The aluminium end tanks are precision-shaped to distribute air across the massive 152mm core depth, ensuring every row of the core is utilized effectively.

The Process West Stage 4 Kit is the definitive choice for the "extreme" Ford FG build. 

By combining a massive 6-inch thick core with a high-flow 3.5-inch induction path, this kit provides the ultimate thermal overhead for world-class horsepower targets.

The Process West Street Air Box is a direct replacement for the factory air box and intake tract on the FG Falcon, sharing the same core design philosophy as the Process West 4 inch Race Air Box system.

High-flow intake, built for the street.

A 6 inch internal diameter K&N filter feeds into a custom spun aluminium trumpet and 4 inch mandrel bent aluminium piping, delivering maximum airflow with significantly less restriction than the factory setup. The result is improved throttle response and more consistent power delivery across the rev range, along with a more aggressive intake sound under load.

Broad compatibility.

The Street Air Box works with the factory intercooler piping and all three stages of the Process West Intercooler system, making it a clean and compatible upgrade regardless of where your build currently sits.

A proven, high-flow intake solution for any street-driven FG Falcon build.

If you have the Process West VB FA24 Intake Manifold, and would like a “TGV Delete”, please email sales@processwest.com.au.

The Process West Throttle Body Relocation Kit was developed to solve a common problem with BA/BF Falcon performance builds, delivering shorter intercooler piping, a cleaner engine bay, and full 3-inch pipe sizing without compromise.

Why relocate the throttle body?

Running 3-inch intercooler piping over the top of the engine into the factory throttle body position causes rubbing on the underside of the bonnet. The Process West kit eliminates this issue entirely by relocating the throttle body to a position that allows true 3-inch piping throughout, without clearance problems.

The shorter, more direct piping path also delivers a measurable improvement in throttle response, and the result is a significantly cleaner and more purposeful engine bay presentation.

Plug-in wiring extension.

Relocating the throttle body requires the wiring to be extended. To keep installation simple, the kit includes purpose-built plug-in patch harnesses that connect directly to the factory loom with no cutting or splicing required.

A well-engineered solution for any serious BA/BF Falcon build.

The Process West Throttle Elbow Kit is a purpose-built component designed to complete the Stage 1 and Stage 2 intercooler piping installation on the Ford Falcon FG, ensuring a clean, precise connection at the throttle body.

A straightforward, quality addition to any FG Falcon Stage 1 or Stage 2 piping setup.

The Process West Top Mount Intercooler was developed with a single goal — to be the very best aftermarket top mount intercooler for the WRX and STI, without compromise.

Every competitor product was studied. Every common mistake was addressed.

The most common error in aftermarket top mount intercooler design is supplying a larger core without properly sized ducting to match. Fitting a larger intercooler and leaving the factory bonnet splitter in place means up to 50% of the new core receives no ambient airflow. A waste of the upgrade.

The images below demonstrate this using the Process West intercooler installed in a 2006 Forester XT, with the factory splitter placed over the core as if the bonnet were shut. The result is evident.

The solution is clear: a splitter sized specifically for the upgraded core, ensuring 100% of the core receives full ambient airflow.

Process West intercooler and splitter/combination showing 100% of the new larger intercooler with full ambient airflow over the entire core.

The image above shows a 2005 WRX with the bonnet scoop removed and the factory splitter still in place. The white line marks the actual footprint of the upgraded intercooler beneath it. The mismatch is obvious. Upgrading the intercooler without upgrading the ducting achieves very little.

Core thickness matters.

The second mistake we commonly see is building an intercooler that's too thick. Bigger core dimensions make for compelling marketing, but physics tells a different story.

A top mount intercooler sits at 90 degrees to ambient airflow. On a boxer engine, that air has already made a 90-degree turn through the bonnet scoop before it reaches the core. Asking it to then push through 114mm of intercooler core is too much to ask. The result is restricted airflow, poor heat exchange, and high intake temperatures.

The Process West core is 90mm thick. That is the optimum balance between cooling surface area and airflow resistance, and it shows in the outlet temperatures and power figures.

Y-pipe distribution.

Most aftermarket Y-pipes distribute charge air unevenly, with one well-flowing duct and a poorly considered second outlet. The Process West Y-pipe is engineered for even charge air distribution across the full width of the intercooler core.

Together, the correctly sized core, splitter, and Y-pipe form a complete top mount intercooler system for the Subaru WRX and STI.

This picture above shows the complete combination of Y-pipe (underneath), intercooler and splitter.

Dyno testing.

It's worth noting that dynos and top mount intercoolers are not an ideal combination. Regardless of fan positioning, airflow into the bonnet scoop on a dyno is minimal. With that said, both the factory intercooler and the Process West upgrade were tested under identical conditions, making for a fair and accurate comparison.

The test vehicle was an otherwise stock 2005 WRX running a BPM GT exhaust. Stock WRXs of this specification consistently produce around 90kW at the wheels on this dyno. Intercooler outlet temperatures were measured via probe placed in the silicone joiner at the throttle body.

Running the PW intercooler and splitter first, the baseline power result was 115.5kW, with a peak outlet temperature of 51°C. The factory intercooler was then installed and tested under the same conditions. Maximum power dropped to 107.5kW, and the factory unit's thermal performance was far more concerning than the power figure alone suggests.

This graph (above) shows the before and after power. Note the test number. These 2 runs were back-to-back.

Intercooler outlet temperature comparison — Process West (dark line) vs. factory unit (light line). Both intercoolers started at 37°C under identical conditions. The Process West unit peaked at 51°C. The factory unit peaked at 66°C. Results shown after a single run.

A final test measured the effect of back-to-back runs on the factory intercooler. After three consecutive runs, outlet temperatures climbed to 84°C and were still rising. The implications for circuit use are significant.

Street testing tells the most honest story.

Testing tells the most honest story. Intercooler outlet temperatures were measured using a Fluke 87 digital multimeter with a K-type thermocouple positioned just before the throttle body, the same location used during dyno testing. Readings from this setup were consistently within one degree of the dyno's AIT probe throughout.

With the Process West intercooler and splitter fitted, hard driving through the mountains could not push outlet temperatures above 43°C regardless of how hard the car was pushed.

The factory intercooler and splitter were refitted and the same route driven under identical conditions. Outlet temperatures peaked at 72°C and were still climbing when testing ended. The difference in the car's response was immediate.

The numbers speak for themselves. The Process West Top Mount Intercooler is the definitive cooling upgrade for the Subaru WRX and STI.

The Process West Top Mount Intercooler was developed with a single goal — to be the very best aftermarket top mount intercooler for the WRX and STI, without compromise.

Every competitor product was studied. Every common mistake was addressed.

The most common error in aftermarket top mount intercooler design is supplying a larger core without properly sized ducting to match. Fitting a larger intercooler and leaving the factory bonnet splitter in place means up to 50% of the new core receives no ambient airflow. A waste of the upgrade.

The images below demonstrate this using the Process West intercooler installed in a 2006 Forester XT, with the factory splitter placed over the core as if the bonnet were shut. The result is evident.

The solution is clear: a splitter sized specifically for the upgraded core, ensuring 100% of the core receives full ambient airflow.

Process West intercooler and splitter/combination showing 100% of the new larger intercooler with full ambient airflow over the entire core.

The image above shows a 2005 WRX with the bonnet scoop removed and the factory splitter still in place. The white line marks the actual footprint of the upgraded intercooler beneath it. The mismatch is obvious. Upgrading the intercooler without upgrading the ducting achieves very little.

Core thickness matters.

The second mistake we commonly see is building an intercooler that's too thick. Bigger core dimensions make for compelling marketing, but physics tells a different story.

A top mount intercooler sits at 90 degrees to ambient airflow. On a boxer engine, that air has already made a 90-degree turn through the bonnet scoop before it reaches the core. Asking it to then push through 114mm of intercooler core is too much to ask. The result is restricted airflow, poor heat exchange, and high intake temperatures.

The Process West core is 90mm thick. That is the optimum balance between cooling surface area and airflow resistance, and it shows in the outlet temperatures and power figures.

Y-pipe distribution.

Most aftermarket Y-pipes distribute charge air unevenly, with one well-flowing duct and a poorly considered second outlet. The Process West Y-pipe is engineered for even charge air distribution across the full width of the intercooler core.

Together, the correctly sized core, splitter, and Y-pipe form a complete top mount intercooler system for the Subaru WRX and STI.

This picture above shows the complete combination of Y-pipe (underneath), intercooler and splitter.

Dyno testing.

It's worth noting that dynos and top mount intercoolers are not an ideal combination. Regardless of fan positioning, airflow into the bonnet scoop on a dyno is minimal. With that said, both the factory intercooler and the Process West upgrade were tested under identical conditions, making for a fair and accurate comparison.

The test vehicle was an otherwise stock 2005 WRX running a BPM GT exhaust. Stock WRXs of this specification consistently produce around 90kW at the wheels on this dyno. Intercooler outlet temperatures were measured via probe placed in the silicone joiner at the throttle body.

Running the PW intercooler and splitter first, the baseline power result was 115.5kW, with a peak outlet temperature of 51°C. The factory intercooler was then installed and tested under the same conditions. Maximum power dropped to 107.5kW, and the factory unit's thermal performance was far more concerning than the power figure alone suggests.

This graph (above) shows the before and after power. Note the test number. These 2 runs were back-to-back.

Intercooler outlet temperature comparison — Process West (dark line) vs. factory unit (light line). Both intercoolers started at 37°C under identical conditions. The Process West unit peaked at 51°C. The factory unit peaked at 66°C. Results shown after a single run.

A final test measured the effect of back-to-back runs on the factory intercooler. After three consecutive runs, outlet temperatures climbed to 84°C and were still rising. The implications for circuit use are significant.

Street testing tells the most honest story.

Testing tells the most honest story. Intercooler outlet temperatures were measured using a Fluke 87 digital multimeter with a K-type thermocouple positioned just before the throttle body, the same location used during dyno testing. Readings from this setup were consistently within one degree of the dyno's AIT probe throughout.

With the Process West intercooler and splitter fitted, hard driving through the mountains could not push outlet temperatures above 43°C regardless of how hard the car was pushed.

The factory intercooler and splitter were refitted and the same route driven under identical conditions. Outlet temperatures peaked at 72°C and were still climbing when testing ended. The difference in the car's response was immediate.

The numbers speak for themselves. The Process West Top Mount Intercooler is the definitive cooling upgrade for the Subaru WRX and STI.

The Process West Top Mount Intercooler was developed with a single goal — to be the very best aftermarket top mount intercooler for the WRX and STI, without compromise.

Every competitor product was studied. Every common mistake was addressed.

The most common error in aftermarket top mount intercooler design is supplying a larger core without properly sized ducting to match. Fitting a larger intercooler and leaving the factory bonnet splitter in place means up to 50% of the new core receives no ambient airflow. A waste of the upgrade.

The images below demonstrate this using the Process West intercooler installed in a 2006 Forester XT, with the factory splitter placed over the core as if the bonnet were shut. The result is evident.

The solution is clear: a splitter sized specifically for the upgraded core, ensuring 100% of the core receives full ambient airflow.

Process West intercooler and splitter/combination showing 100% of the new larger intercooler with full ambient airflow over the entire core.

The image above shows a 2005 WRX with the bonnet scoop removed and the factory splitter still in place. The white line marks the actual footprint of the upgraded intercooler beneath it. The mismatch is obvious. Upgrading the intercooler without upgrading the ducting achieves very little.

Core thickness matters.

The second mistake we commonly see is building an intercooler that's too thick. Bigger core dimensions make for compelling marketing, but physics tells a different story.

A top mount intercooler sits at 90 degrees to ambient airflow. On a boxer engine, that air has already made a 90-degree turn through the bonnet scoop before it reaches the core. Asking it to then push through 114mm of intercooler core is too much to ask. The result is restricted airflow, poor heat exchange, and high intake temperatures.

The Process West core is 90mm thick. That is the optimum balance between cooling surface area and airflow resistance, and it shows in the outlet temperatures and power figures.

Y-pipe distribution.

Most aftermarket Y-pipes distribute charge air unevenly, with one well-flowing duct and a poorly considered second outlet. The Process West Y-pipe is engineered for even charge air distribution across the full width of the intercooler core.

Together, the correctly sized core, splitter, and Y-pipe form a complete top mount intercooler system for the Subaru WRX and STI.

This picture above shows the complete combination of Y-pipe (underneath), intercooler and splitter.

Dyno testing.

It's worth noting that dynos and top mount intercoolers are not an ideal combination. Regardless of fan positioning, airflow into the bonnet scoop on a dyno is minimal. With that said, both the factory intercooler and the Process West upgrade were tested under identical conditions, making for a fair and accurate comparison.

The test vehicle was an otherwise stock 2005 WRX running a BPM GT exhaust. Stock WRXs of this specification consistently produce around 90kW at the wheels on this dyno. Intercooler outlet temperatures were measured via probe placed in the silicone joiner at the throttle body.

Running the PW intercooler and splitter first, the baseline power result was 115.5kW, with a peak outlet temperature of 51°C. The factory intercooler was then installed and tested under the same conditions. Maximum power dropped to 107.5kW, and the factory unit's thermal performance was far more concerning than the power figure alone suggests.

This graph (above) shows the before and after power. Note the test number. These 2 runs were back-to-back.

Intercooler outlet temperature comparison — Process West (dark line) vs. factory unit (light line). Both intercoolers started at 37°C under identical conditions. The Process West unit peaked at 51°C. The factory unit peaked at 66°C. Results shown after a single run.

A final test measured the effect of back-to-back runs on the factory intercooler. After three consecutive runs, outlet temperatures climbed to 84°C and were still rising. The implications for circuit use are significant.

Street testing tells the most honest story.

Testing tells the most honest story. Intercooler outlet temperatures were measured using a Fluke 87 digital multimeter with a K-type thermocouple positioned just before the throttle body, the same location used during dyno testing. Readings from this setup were consistently within one degree of the dyno's AIT probe throughout.

With the Process West intercooler and splitter fitted, hard driving through the mountains could not push outlet temperatures above 43°C regardless of how hard the car was pushed.

The factory intercooler and splitter were refitted and the same route driven under identical conditions. Outlet temperatures peaked at 72°C and were still climbing when testing ended. The difference in the car's response was immediate.

The numbers speak for themselves. The Process West Top Mount Intercooler is the definitive cooling upgrade for the Subaru WRX and STI.

The Process West Top Mount Intercooler (TMIC) for the 2007–2009 Liberty/Legacy GT is engineered to deliver the cooling capacity of a front-mount system while maintaining the response of a top-mount setup. By focusing on both core volume and airflow distribution, this kit provides a significant performance ceiling for your EJ-series engine.

Optimised Thermal Exchange

Simply increasing the size of an intercooler isn't enough; you must ensure ambient air reaches the entire surface area. The Process West system addresses this by pairing a massive core with a revised under-hood duct, ensuring maximum heat exchange across every fin.

• Massive Core Dimensions: Features a 400mm flow length—nearly double the size of the factory unit.

• Bar & Plate Technology: Utilises a high-efficiency 90mm thick bar and plate core, specifically chosen to balance superior cooling with minimal pressure drop.

• Maximised Airflow: The included vehicle-specific ducting force-feeds air across the entire core, preventing the "dead spots" common in oversized intercoolers using factory shrouds.

Key Benefits

• Consistent Power: Dramatically reduces heat soak, allowing for consistent boost and timing during spirited driving.

• Engine Safety: Lower intake air temperatures (IATs) reduce the risk of detonation, providing a safer environment for increased tuning levels.

• Direct Fitment: Engineered as a comprehensive upgrade that integrates seamlessly with the 2007–2009 GT chassis.

The Process West TMIC is the ultimate cooling foundation for the Liberty/Legacy GT, providing a "small front-mount" cooling profile in a convenient top-mount package.

The Process West Top Mount Intercooler for the 2008+ GRB and VA STI is the largest top mount intercooler Process West produces for the Subaru platform, and currently the largest available option for 2015+ models. Everything required for installation is included in the kit.

Massive bar and plate core. At 530 x 193 x 90mm, this bar and plate core delivers a substantial increase in cooling surface area over the factory unit, providing lower intake air temperatures, improved throttle response, and more consistent power across the rev range.

Y-pipe charge distribution. The kit includes the Process West Silicone Y-Pipe, the connection between the turbo compressor outlet and the intercooler. Most aftermarket Y-pipes distribute charge air unevenly, with one well-flowing duct and a poorly designed second outlet. The Process West Y-Pipe is engineered for even charge air distribution across the full width of the intercooler core, ensuring the full potential of the upgraded core is realised.

Together, the oversized core and balanced Y-pipe form a complete, properly engineered top mount intercooler system for the GRB and VA STI.

The Process West Top Mount Intercooler for the 1997–98 GC8 WRX and STI was developed with a single goal: to be the very best aftermarket top mount intercooler for the platform, without compromise.

Every competitor product was studied. Every common mistake was addressed.

The ducting problem nobody else solves.

The most common error in aftermarket top mount intercooler design is supplying a larger core without properly sized ducting to match. Fitting a larger intercooler and leaving the factory bonnet splitter in place means a significant portion of the new core receives no ambient airflow whatsoever. It is a pointless exercise.

The Process West solution is a purpose-built bonnet splitter sized specifically for the upgraded core, ensuring 100% of the core receives full ambient airflow. Combined with the intercooler, it is the most complete and capable top mount intercooler option available for the GC8.

Largest core on the market.

At 490 x 175 x 90mm, the Process West core is by far the largest top mount intercooler available for the GC8 platform. The 90mm core thickness is a deliberate engineering choice, balancing maximum cooling surface area with the airflow resistance characteristics of a bonnet scoop mounted intercooler, delivering lower outlet temperatures and more power where it counts.

The definitive top mount intercooler upgrade for the Subaru GC8 WRX and STI.

The Process West Top Mount Intercooler for the 1999–00 GC8 WRX and STI was developed with a single goal: to be the very best aftermarket top mount intercooler for the platform, without compromise.

Every competitor product was studied. Every common mistake was addressed.

The ducting problem nobody else solves.

The most common error in aftermarket top mount intercooler design is supplying a larger core without properly sized ducting to match. Fitting a larger intercooler and leaving the factory bonnet splitter in place means a significant portion of the new core receives no ambient airflow whatsoever. It is a pointless exercise.

The Process West solution is a purpose-built bonnet splitter sized specifically for the upgraded core, ensuring 100% of the core receives full ambient airflow. Combined with the intercooler, it is the most complete and capable top mount intercooler option available for the GC8.

Largest core on the market.

At 490 x 175 x 90mm, the Process West core is by far the largest top mount intercooler available for the GC8 platform. The 90mm core thickness is a deliberate engineering choice, balancing maximum cooling surface area with the airflow resistance characteristics of a bonnet scoop mounted intercooler, delivering lower outlet temperatures and more power where it counts.

The definitive top mount intercooler upgrade for the Subaru GC8 WRX and STI.

The goal for the Process West Top Mount Intercooler was simple. Engineer the best-performing aftermarket top-mount on the market. By studying the common failures in the aftermarket, like poor ducting and inefficient core thickness, we built a cooling solution that sets a new standard for the Subaru platform.

This TMIC does not include a splitter, though we strongly recommend running one. See our other models that include vehicle-specific splitters.

What's included

• Process West 90mm intercooler core
  High-flow moulded silicone Y-pipe
  Mounting hardware and fittings

Optimal core thickness: 90mm
Many competitors push 114mm (4.5") cores on a "bigger is better" pitch. For a top-mount, where air has to make a sharp 90 degree turn through a bonnet scoop, too much thickness just creates resistance.

Our design uses a 90mm (3.5") core. The air breathes through the core instead of hitting a wall. The result is lower outlet temps and more consistent power.

High-flow silicone Y-pipe
Standard aftermarket Y-pipes often push air unevenly, favouring one side of the core. Our custom-moulded silicone Y-pipe is built for even charge-air distribution across the entire entry tank.

Proven performance
Dyno testing is notoriously hard for top-mounts due to limited scoop airflow. Even so, back-to-back testing on our '05 WRX against the factory unit returned clear gains.

• Power: 115.5kW, up from the factory 107.5kW.
• Thermal control: the PW unit peaked at 51°C in static dyno conditions, against 66°C for the stock unit.

Under three back-to-back runs to simulate heavy load, factory outlet temps climbed to 84°C. The Process West unit stayed far more stable.

Out on the road is the real test. During spirited mountain driving, the stock intercooler peaked at 72°C and kept climbing, with a noticeable loss of liveliness. The Process West system never exceeded 43°C.

Upgrade to the Process West TMIC and keep your Subaru cool, responsive and reliable under any conditions. Pair it with the matching hood scoop for your model to get the full benefit of the system.

The Process West Top Mount Intercooler is the largest top mount upgrade available for the 2022+ VB WRX. Engineered to extract the full potential of the platform, it delivers improved cooling efficiency, reduced turbo lag, and sharper throttle response.

Largest core on the market.
At 193 x 523 x 110mm, this intercooler outperforms any comparable top mount option for the VB WRX.

Dual entry design.
A unique dual entry configuration ensures optimal airflow distribution across the entire core, resulting in more consistent cooling and improved power output across the rev range.

Available in two finishes.
Choose between a clean raw aluminium or stealth black finish to suit your build.

15-minute installation.
Designed for a straightforward, bolt-on fit with no cutting or permanent modification required. Most installations are completed in under 15 minutes.
The definitive top mount intercooler upgrade for your VB WRX build.

The goal for the Process West Top Mount Intercooler (TMIC) was simple: to engineer the best-performing aftermarket top-mount on the market. By analyzing common industry failures—such as poor ducting and inefficient core thickness—we have developed a cooling solution that sets a new standard for the Subaru platform.

The Critical Factor: Proper Ducting

A common mistake in the aftermarket is supplying a larger intercooler without the necessary ducting to support it. Installing a massive core while retaining the factory under-bonnet shroud is a waste of resources; the factory shroud simply cannot distribute air across the increased surface area.

For demonstration, we placed a factory shroud over our upgraded core:

As shown, approximately 50% of the upgraded intercooler receives no ambient airflow with the stock ducting. The image below shows the Process West solution: a custom-sized splitter that ensures 100% of the core receives direct, high-velocity ambient air.

The white outline in the image above illustrates the actual dimensions of the intercooler hidden beneath a factory WRX splitter. Without the correct ducting, the extra core size is essentially useless.

Optimised Core Thickness: 90mm vs. 114mm

Many competitors market 114mm (4.5") cores based on the "bigger is better" philosophy. However, for a top-mount application where air must make a sharp 90-degree turn through a bonnet scoop, excessive thickness creates too much resistance.

• Our Design: We utilize a 90mm (3.5") core.

• The Result: This thickness allows the air to actually "breathe" through the core rather than hitting a wall of resistance. This results in lower outlet temperatures and more consistent power.

High-Flow Silicone Y-Pipe

Standard aftermarket Y-pipes often suffer from uneven air distribution, favoring one side of the intercooler. Our custom-molded silicone Y-pipe is designed for perfect charge-air distribution across the entire entry tank.

Shown above: The complete system featuring the optimized Y-pipe, intercooler core, and custom splitter.

Data-Driven Performance

Dyno Testing

While dynos are notoriously difficult for top-mount testing due to limited scoop airflow, back-to-back testing against the factory unit on an '05 WRX revealed significant gains:

• Power Increase: The Process West system delivered 115.5kW, compared to the factory 107.5kW.

• Thermal Control: Even in static dyno conditions, the PW unit peaked at 51°C, while the stock unit climbed to 66°C.

(Power Graph: Before vs. After) ^^

(Temperature Graph: Before vs. After) 

When subjected to three back-to-back runs to simulate heavy load, the factory intercooler outlet temps skyrocketed to 84°C, whereas the Process West unit remained significantly more stable.

(Heat Soak Comparison Graph)

Real-World Street Testing

The true test happens on the road. During spirited mountain driving:

• Stock Intercooler: Temperatures peaked at 72°C and continued to rise, resulting in a noticeable loss of engine "liveliness."

• Process West System: Despite aggressive driving, outlet temperatures never exceeded 43°C.

Upgrade to the Process West TMIC Kit to ensure your Forester XT stays cool, responsive, and reliable under any conditions.

Went and did the same hard driving and saw a peak of 72C which would probably have kept rising but I decided that was enough. The car also felt a lot less lively.

Note: Designed for use with the 2002 STi High-Flow Bonnet Scoop

The goal for the Process West Top Mount Intercooler (TMIC) was simple: to engineer the best-performing aftermarket top-mount on the market. By analyzing common industry failures—such as poor ducting and inefficient core thickness—we have developed a cooling solution that sets a new standard for the Subaru platform.

The Critical Factor: Proper Ducting

A common mistake in the aftermarket is supplying a larger intercooler without the necessary ducting to support it. Installing a massive core while retaining the factory under-bonnet shroud is a waste of resources; the factory shroud simply cannot distribute air across the increased surface area.

For demonstration, we placed a factory shroud over our upgraded core:

As shown, approximately 50% of the upgraded intercooler receives no ambient airflow with the stock ducting. The image below shows the Process West solution: a custom-sized splitter that ensures 100% of the core receives direct, high-velocity ambient air.

The white outline in the image above illustrates the actual dimensions of the intercooler hidden beneath a factory WRX splitter. Without the correct ducting, the extra core size is essentially useless.

Optimised Core Thickness: 90mm vs. 114mm

Many competitors market 114mm (4.5") cores based on the "bigger is better" philosophy. However, for a top-mount application where air must make a sharp 90-degree turn through a bonnet scoop, excessive thickness creates too much resistance.

• Our Design: We utilize a 90mm (3.5") core.

• The Result: This thickness allows the air to actually "breathe" through the core rather than hitting a wall of resistance. This results in lower outlet temperatures and more consistent power.

High-Flow Silicone Y-Pipe

Standard aftermarket Y-pipes often suffer from uneven air distribution, favoring one side of the intercooler. Our custom-molded silicone Y-pipe is designed for perfect charge-air distribution across the entire entry tank.

Shown above: The complete system featuring the optimized Y-pipe, intercooler core, and custom splitter.

Data-Driven Performance

Dyno Testing

While dynos are notoriously difficult for top-mount testing due to limited scoop airflow, back-to-back testing against the factory unit on an '05 WRX revealed significant gains:

• Power Increase: The Process West system delivered 115.5kW, compared to the factory 107.5kW.

• Thermal Control: Even in static dyno conditions, the PW unit peaked at 51°C, while the stock unit climbed to 66°C.

(Power Graph: Before vs. After) ^^

(Temperature Graph: Before vs. After) 

When subjected to three back-to-back runs to simulate heavy load, the factory intercooler outlet temps skyrocketed to 84°C, whereas the Process West unit remained significantly more stable.

(Heat Soak Comparison Graph)

Real-World Street Testing

The true test happens on the road. During spirited mountain driving:

• Stock Intercooler: Temperatures peaked at 72°C and continued to rise, resulting in a noticeable loss of engine "liveliness."

• Process West System: Despite aggressive driving, outlet temperatures never exceeded 43°C.

Upgrade to the Process West TMIC Kit to ensure your Forester XT stays cool, responsive, and reliable under any conditions.

The Transmission Cooler Kit provides consistent thermal management for vehicles operating in high stress environments. Featuring a high performance bar and plate core and billet end tanks, the system increases cooling efficiency to ensure the gearbox remains within its ideal temperature range during heavy use.

A critical design element of this kit is its integration with the factory heat exchanger. Retaining the factory exchanger within the cooling loop is essential for maintaining proper fluid temperatures during light and medium loads, as it prevents the transmission from operating at temperatures that are too low for optimal performance.

To ensure the integrity of the system, the kit is equipped with Gates LOLA 300 psi hose and 400 series Speedflow fittings. These components are selected for their durability and their ability to provide a secure, reliable connection for the lifespan of the vehicle.

The Process West Transmission Cooler Kit offers a functional and precise cooling solution for drivers who require dependable performance and long term mechanical protection.

The Transmission Cooler Kit provides consistent thermal management for vehicles operating in high stress environments. Featuring a high performance bar and plate core and billet end tanks, the system increases cooling efficiency to ensure the gearbox remains within its ideal temperature range during heavy use.

A critical design element of this kit is its integration with the factory heat exchanger. Retaining the factory exchanger within the cooling loop is essential for maintaining proper fluid temperatures during light and medium loads, as it prevents the transmission from operating at temperatures that are too low for optimal performance.

To ensure the integrity of the system, the kit is equipped with Gates LOLA 300 psi hose and 400 series Speedflow fittings. These components are selected for their durability and their ability to provide a secure, reliable connection for the lifespan of the vehicle.

The Process West Transmission Cooler Kit offers a functional and precise cooling solution for drivers who require dependable performance and long term mechanical protection.