The HKS bolt on turbo kit for the GTIIIRS with part number zn8zd8 designed for the FA24 11001KT007 brings factory compatible power gains to Subaru legacy and Impreza platforms. This kit targets enthusiasts who want a bolt on solution that preserves reliability while opening the door to controlled boost levels.
By integrating HKS engineering with the existing FA24 architecture, this setup minimizes fabrication while maximizing response and drivability. Below is a detailed breakdown of the kit components, performance expectations, and real world installation considerations.
| Kit Part Number | Application | Turbo Model | Target Power Range |
|---|---|---|---|
| zn8zd8 11001KT007 | Subaru FA24 (GTIIIRS) | HKS GT28 Precision Turbo | 280–380 hp (dependent on fueling and tuning) |
| Bolt On Configuration | OEM manifold compatibility | Includes manifold adapter and gaskets | Minimal machining required |
| Pressure Target | Stage 2 daily driving | 0.6–0.8 bar typical | Optimized for pump fuel with ignition advance |
| Included Core Components | Turbocharger, wastegate, oil lines | HGS blow off valve and mounting kit | High temperature silicone couplers |
HKS GT28 Turbo Integration Details
At the heart of the zn8zd8 11001KT007 is the HKS GT28 turbocharger, chosen for quick spool and durable compressor maps. The bolt on design uses a precision adapter that aligns with the Subaru FA24 manifold, allowing the turbo to seal without extensive milling or welding. Pressure is controlled by an external wastegate actuator that ties into the factory vacuum line points, keeping installation familiar for shops.
Oil feed and drain are routed through newly supplied high pressure lines that connect to the stock gallery, ensuring consistent lubrication at higher loads. The turbo compressor feeds an aluminum inlet pipe that transitions to a silicone coupler, reducing heat soak and minimizing boost leaks. This integration approach delivers spool between 2000 and 2500 rpm, making power feel progressive rather than abrupt.
Performance Tuning and Boost Control
To extract safe power from the FA24, the kit relies on a standalone ECU or a modified factory unit with custom ignition and fueling maps. Target boost is usually set around 0.6 bar for daily drive conditions, with the option to pull to 0.8 bar on high octane fuel. Ignition timing is pulled back under high load to protect the rings and maintain cylinder head integrity.
Dyno results show a typical gain of 80–120 hp over the naturally aspirated baseline, with torque increases spread across the mid and upper rpm band. Air fuel ratio stays within safe limits around 12.5:1 to 13:1 on pump gas, while on race gas the lambda can be nudged leaner for extra responsiveness. Proper tuning is essential to achieve the promised performance without compromising long term reliability.
Installation Considerations and Compatibility
Mechanics appreciate that the HKS bolt on kit for zn8zd8 11001KT007 uses many OEM reference points, reducing the need for custom brackets. The turbo mount bolts to reinforced pads that transfer vibration away from brittle plastic components. Some vehicles may require trimming of splash shields or relocation of the battery to clear the intercooler piping, which should be planned before purchase.
Cooling is addressed through larger factory style radiators and an upgraded front mount intercooler that maintains charge temperature under repeated pulls. The intercooler core is selected to match the airflow of the GT28, avoiding excessive pressure drop that would defeat the purpose of the turbo upgrade. When combined with a high volume fuel pump and methanol injection, the platform can support even more aggressive power targets.
Reliability, Warranty, and Daily Usability
Daily driven cars benefit from the conservative boost targets and the use of HKS proprietary components that are tested for longevity. The kit includes a high temperature oil catch can to reduce carbon buildup in the intake ports, and the turbine housing is selected to avoid surge at part throttle. Cold start warm up remains close to stock, and limp mode strategies are designed to protect the turbo during harsh starts.
Warranty coverage varies by seller, so buyers should confirm whether the mapping, turbo internals, and plumbing are included in the service plan. For track use, higher boost and ignition advance can be dialed in with a professional tune, while street legal versions prioritize refinement and compliance. When installed and tuned correctly, the setup has proven reliability spanning years of spirited driving.
Key Takeaways for the FA24 GTIIIRS HKS Turbo Kit
- Use zn8zd8 11001KT007 for a balanced mix of responsiveness and daily comfort on FA24 platforms.
- Plan for professional tuning to map ignition, wastegate, and air fuel ratio safely.
- Upgrade the intercooler, fuel pump, and oil catch can to support higher boost targets.
- Monitor boost leaks and wastegate chatter during initial break in to ensure proper seating.
- Keep ignition timing conservative on low octane fuel to protect the engine and turbo.
FAQ
Reader questions
Will this turbo kit work with the factory ECU on my GTIIIRS?
Factory ECU tuning is often insufficient for safe boost control on this kit; a standalone ECU or heavily modified firmware is recommended to manage ignition timing, fueling, and wastegate duty cycle.
What fuel requirement is needed for the 11001KT007 setup?
91 octane pump fuel is suitable for moderate boost levels, while 93 octane or race fuel is preferred when running boost above 0.7 bar to prevent knock.
Does the kit include an intercooler, and what size is recommended?
The zn8zd8 kit includes piping and mounting hardware, but an up sized front mount intercooler should be added to control charge temperatures during repeated pull sessions.
Can this turbo kit be converted later to a larger turbo without redoing the manifold?
Yes, the OEM style adapter allows for a larger turbo swap later, though minor trimming and recalibration may be required to maintain smooth power delivery and reliability.