Spec G30-660 Turbo Kit + Custom Tune — 2022+ Subaru WRX VB

The GropeTuned Spec G30-660 is a custom turbocharger designed specifically around the usable powerband of the FA24F-powered 2022+ Subaru WRX.

I am moving away from the standard off-the-shelf Taiwanese G-series replacement turbos and offering my own custom G30-660 configuration. This turbo uses a custom wheel combination selected to provide stronger performance within the FA24F’s ideal operating range, which is approximately 7,000 rpm or less for most builds.

• Custom 7+7 billet compressor wheel

• Custom 5+5 split-blade turbine wheel

• Larger turbine wheel than the turbo shown in the current listing photos

• Compressor and turbine combination selected specifically for the FA24F powerband

• Direct-swap fitment for the 2022+ WRX

Testing of this wheel combination has shown gains of approximately 20 horsepower and 30 lb-ft of torque over comparable current Garrett offerings within the FA24F’s useful RPM range.

This turbo is intended for VB WRX owners targeting approximately 500 wheel horsepower with the proper fuel system, supporting modifications and tuning.

The G30-sized turbine provides a much better match for a 660-size compressor than a smaller G25 turbine setup. This allows the turbo to make better use of the compressor’s airflow capability without needing to operate the engine at an excessively high RPM.

It provides a strong balance of:

• Spool response

• Top-end airflow

• Transient response

• Controlled torque delivery

• Street drivability

• Drivetrain-friendly power delivery

Actual power will depend on fuel type, boost pressure, tuning, engine condition, supporting modifications, elevation and drivetrain configuration.

The factory VB WRX turbo produces a sharp surge of torque at low RPM. While that can feel responsive, the sudden torque spike places significant stress on the transmission, rods and the rest of the drivetrain.

The GropeTuned Spec G30-660 delivers power more progressively.

Instead of producing its hardest torque hit at very low RPM, it builds boost smoothly and continues carrying airflow through the upper portion of the powerband. This provides stronger overall performance while reducing the harsh low-RPM torque spike associated with the factory turbo.

The result is a powerband that is better suited for a higher-horsepower VB WRX.

The following response figures were recorded on a running VB WRX setup. Exact spool will vary depending on exhaust configuration, boost target, tuning, gear, fuel and engine setup.

• 1st gear: Approximately 14–18 psi

• 2nd gear: Full boost by approximately 4,500 rpm

• 3rd gear: Full boost by approximately 3,500 rpm

This is where the turbo performs especially well.

• 1st gear: Approximately 14–18 psi

• 2nd gear: Full boost immediately after the shift

• 3rd gear: Full boost immediately after the shift

Although initial spool takes slightly longer than the factory turbo during a single isolated pull, the rotating assembly carries energy extremely well between shifts.

Once the turbo is operating within its intended range, boost returns immediately during gear changes and the car continues pulling hard through each gear.

The key advantage of this turbo is its transient response.

A turbo should not be judged only by the RPM at which it reaches full boost during one isolated pull. How quickly it recovers after a shift is just as important in real-world driving.

The GropeTuned Spec G30-660 retains turbine speed extremely well between gear changes. This means that once the turbo is spooled, it remains responsive throughout the remainder of the pull.

The result is:

• Immediate boost recovery after shifts

• Strong acceleration through multiple gears

• Minimal waiting for the turbo to respool

• Power that continues pulling toward redline

• Better performance during actual street and track use

The turbo carries power cleanly to the factory redline and can support higher engine speeds when used with an appropriately built and tuned engine. Engine-speed limits depend on the engine build and calibration. The personal-car analytical log shown on this site uses the GropeTuned Spec G25-660 on 93 octane + water-methanol injection (WMI); it is not a G30 test result.

• GropeTuned Spec G30-660 turbocharger

• Turbo mounting studs

• Required oil and coolant hoses

• Turbo gaskets

• Complete mounting hardware

• Components required for direct installation on a 2022+ Subaru WRX

This is a complete direct-swap turbo kit designed to bolt onto the VB WRX using the included installation components.

Professional tuning and appropriate supporting modifications are required before operating the vehicle under boost.

Important: The production turbo will use a larger turbine wheel than the wheel shown in the current listing photos.

Default matched package: this turbo is paired with a full WRX E-tune built around the selected turbo and your supporting mods.

The calibration in this kit is built around your car. These extend what it can do:

• Flex Fuel Tune Add-On — ethanol-aware fuelling, timing and boost that scale with what is actually in the tank
• Speed Density Tune Add-On — MAP-based load calculation, for when the intake tract no longer suits the MAF
• Ask about a Teach-As-We-Go upgrade — this kit already includes tuning; contact me about the teaching upgrade before purchasing a separate tune

• 62mm High-Flow Throttle Body — less restriction at the last turn into the manifold
• BRZ Intake Manifold Adapter Kit — the BRZ-style manifold conversion for the 2022+ VB

A bigger hot side puts more heat into the bay. We make the shielding for it.

• 3-Layer Heat Wrapping Service — send us your header or J-pipe and we build it
• Ultimate Heat Wrap Bundle — materials and the welder to build it yourself