If you own a Porsche 997 GT2 Turbo and you are looking into upgrading or replacing the hotside of your turbo system, getting the correct part numbers is critical. The hotside includes the turbine housing, exhaust manifold, and associated hardware. Using the wrong parts can lead to fitment issues, performance losses, or even damage. This guide covers both factory OEM part numbers and popular aftermarket hotside options for the 997 GT2 Turbo (2007–2009).
Factory OEM Hotside Part Numbers
Porsche uses specific part numbers for the 997 GT2 turbo hotside components. These are the parts as they came from the factory. If you are restoring a stock setup or replacing a damaged component, these numbers ensure a direct fit.
Turbine Housing
- Left side (driver's side): 997.123.019.10
- Right side (passenger's side): 997.123.020.10
These are the cast iron turbine housings for the KKK/K03 turbochargers used on the 997 GT2. They include the wastegate port and the flange for the downpipe.
Exhaust Manifolds
- Left manifold: 997.123.017.10
- Right manifold: 997.123.018.10
The manifolds are cast iron with integrated crossover pipes. They are known to crack under high heat and boost, so many owners upgrade to aftermarket units.
Wastegate Actuator
- Standard wastegate actuator: 997.123.025.10 (often superseded)
The factory wastegate actuator is not adjustable and is a known weak point for holding boost. Many replace it with an aftermarket adjustable unit.
Gaskets and Hardware
- Turbo-to-manifold gasket set: 997.123.023.10 (includes gaskets and crush washers)
- Manifold-to-head gasket: 997.123.021.10 (per bank)
- Downpipe gasket: 997.123.022.10 (for each turbo outlet)
When replacing any hotside component, always use new gaskets and lock nuts. The factory nuts are 10mm and often seize; consider using anti-seize compound.
Aftermarket Hotside Upgrades
For higher horsepower goals, the factory hotside is restrictive. Aftermarket options improve spool, flow, and durability. Below are the most common aftermarket hotside part numbers for the 997 GT2 Turbo.
Upgraded Turbine Housings
- Kline Turbo 997 GT2 billet housings: Kline offers a direct-fit billet aluminum housing (part KTT-997-GT2-HS). They claim up to 30% faster spool and improved flow. These are commonly used with upgraded compressor wheels.
- TTE 997 GT2 housings: TTE (Turbo Technics) provides upgraded cast iron housings with larger inlet and outlet ports (part TTE-997-HS-001). They are a drop-in replacement for the stock K03 housings, allowing for larger turbine wheels.
Aftermarket Exhaust Manifolds
- Mashimarho 997 GT2 tubular manifolds: These are stainless steel equal-length headers (part M-997-GT2-HM). They reduce backpressure and spool time. Fitment is tight, and they require a heat shield delete or modification.
- Cargraphic 997 GT2 manifold upgrade: Part C-997-GT2-MAN. Cast iron with improved internal geometry, direct fit, and stock-like durability.
- FVD Brombacher 997 GT2 sport manifolds: FVD offers both cast and tubular versions. The cast version (part FVD-997-GT2-MC) is a direct OEM replacement but with smoother flow.
Wastegate Upgrades
- Tial MV-R 46mm wastegate: Part TIAL-46-MVR. Requires a custom adapter or replacement hotside housing that accepts external wastegates. This is common for big turbo builds.
- Forge Motorsport RS wastegate actuator: Part FMAC-997-GT2. Adjustable boost pressure. Direct bolt-on to the factory housing, but you must set the preload correctly.
Complete Hotside Kits
Some vendors sell complete hotside kits for the 997 GT2 Turbo. These include manifolds, turbine housings, and wastegates.
- Exact Auto 997 GT2 Stage 2+ hotside kit: Comes with TTE housings, Mashimarho manifolds, and Tial wastegates. All necessary gaskets and hardware included.
- Evo Motorsports 997 GT2 full hotside package: Includes billet housings, equal-length manifolds, and adjustable wastegate actuators. Tuned for 700+ WHP.
Installation Considerations
Replacing the hotside on a 997 GT2 is not a simple weekend job. Here are key points to keep in mind:
- Engine removal vs. in-chassis: Most hotside work on the 997 GT2 can be done in chassis, but the passenger side manifold is very tight. Many shops pull the engine for easier access.
- Heat management: Aftermarket tubular manifolds radiate more heat. Consider ceramic coating or wrapping to protect nearby components and reduce underhood temperatures.
- Wastegate plumbing: If you switch to an external wastegate, you will need to cap the internal wastegate port on the turbine housing and weld a new flange for the external gate. This requires fabrication.
- Tuning: Any hotside change will affect boost response and airflow. The DME (engine control unit) must be recalibrated. A custom tune from a reputable Porsche tuner is essential.
- Supporting mods: Hotside upgrades typically require upgraded fuel system, intercoolers, and intake. Do not expect gains from a hotside alone.
Hotside Part Number Cross-References
If you are buying used turbo parts, verify they are from a 997 GT2 (not a 996 or other variant). The 997 GT2 uses a slightly different flange pattern than the 997 Turbo (non-GT2). Here are some cross-reference tips:
- 997.123.019.10 is unique to the GT2 left housing. The standard 997 Turbo uses 997.123.019.00.
- 997.123.017.10 (left manifold) is GT2-specific; the regular 997 Turbo manifold (997.123.017.00) has different internal dimensions and wastegate port location.
- Avoid 996 parts; they are not compatible without major modifications.
Practical Recommendation
For most 997 GT2 owners looking to upgrade the hotside, the most balanced approach is to replace the factory manifolds with the Mashimarho tubular units and install TTE turbine housings. This combination retains the factory turbo flange positions, reduces restriction, and spools noticeably faster. Budget around $4,500 for the parts alone. If you are on a tighter budget, the FVD cast manifolds paired with a Forge Motorsport actuator are a solid improvement over stock. Always use new OEM gaskets and copper nuts to prevent exhaust leaks. And do not skip the tune—your engine will thank you.
Whether you are chasing every last horsepower or just refreshing your worn-out turbos, having the correct hotside part numbers saves time and frustration. Double-check compatibility with your specific model year (2007–2009) and turbo size before ordering.