Mercedes A45 AMG W176 Tuning Guide

The Mercedes-Benz A45 AMG (W176) and CLA45 AMG (C117) share the same powertrain and drivetrain, making them two of the most exciting performance vehicles in the hot hatch and compact saloon markets. Both cars feature the 2.0-litre turbocharged four-cylinder engine, paired with Mercedes’ 4MATIC all-wheel-drive system and a 7-speed dual-clutch transmission. Due to the similarity in powertrains, tuning options for both models are essentially the same.

In this guide, we will explore the various tuning stages for the A45/CLA45, outlining what can be achieved at each level and the hardware required to reach your desired performance.

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Stage 1 Tuning: Power Gains with Software

Stage 1 tuning is the most straightforward option for improving performance without any major hardware modifications. This stage focuses primarily on optimising the car’s engine software (ECU remapping) to extract more power from the stock components.

For the A45/CLA45, Stage 1 tuning typically involves:

• ECU Remap: A performance tune to the vehicle’s ECU is the cornerstone of Stage 1. This adjusts the turbocharger boost levels, ignition timing, and fuel maps to improve performance. The power gains are usually in the range of 20-40 horsepower, with torque increases of around 50-70 Nm, depending on the software and tuner used.
• Upgraded Intake (Optional): Some tuners will suggest an upgraded air intake, although this is optional at Stage 1. A more efficient intake can help improve airflow into the engine, but it’s not always necessary for a noticeable power increase at this stage.
• Improved Exhaust (Optional): A less restrictive exhaust system, such as a sports cat-back, is sometimes included at this stage. It can enhance the sound and marginally increase performance, but like the intake, it is not essential for Stage 1 tuning.

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Stage 1 is a relatively cost-effective option and is suitable for those looking to improve performance without sacrificing reliability. It’s an ideal starting point if you're seeking a noticeable increase in power without major investment.

Stage 2 Tuning: More Power with Enhanced Hardware

Stage 2 tuning takes the next step, requiring some hardware upgrades alongside an ECU remap. At this level, the goal is to significantly increase power and torque, typically in the range of 400-450 horsepower. This is achieved by removing some of the restrictions in the stock setup, allowing for higher performance levels.

For Stage 2, you would need to upgrade the following components:

• High-Flow Downpipe or Sports Catalytic Converter: One of the key components for Stage 2 tuning is replacing the factory downpipe or cat with a high-flow version. This modification reduces exhaust backpressure, allowing the turbo to spool faster and perform more efficiently, which directly leads to better power delivery.
• Larger Chargecooler: A larger or more efficient Chargecooler will help reduce the intake air temperature, allowing the engine to run more efficiently and produce more power without overheating. This is a common upgrade for those pushing the limits of Stage 2.
• Upgraded Intake System: A more efficient air intake system becomes more important at this stage, as the increased power demands more air. A performance air intake system improves airflow into the engine, contributing to better power output and throttle response.
• ECU Remap: A further tune of the ECU is required to accommodate the hardware changes. This ensures the car is running at its full potential, optimising power delivery and engine response.

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Stage 2 tuning offers a more significant performance boost compared to Stage 1, but it requires a greater investment in hardware and tuning expertise. It is a good option for owners who want to take their A45/CLA45 to the next level, especially those aiming for track performance or more spirited driving.

Stage 3 Tuning: Major Hardware Upgrades and Significant Power Gains

Stage 3 tuning is a major step up and involves significant modifications to the engine and supporting components. At this stage, the goal is typically to exceed 500 horsepower, and it’s a level of tuning that’s suited to enthusiasts who are looking for maximum performance, often with the intention of using the vehicle for track days or drag racing.

However, the costs involved in Stage 3 tuning can escalate quickly due to the extensive upgrades required, as well as the need for a more robust supporting setup to handle the additional power and strain on the vehicle.

Stage 3 upgrades often include:

• Upgraded Turbocharger: The stock turbocharger in the A45/CLA45 can only support so much power. For Stage 3, an upgraded turbo is required, allowing for higher boost pressure and greater airflow. This is one of the most expensive upgrades in this stage.
• Forged Internal Engine Components: To handle the higher levels of boost and power, the engine internals may need to be strengthened with forged pistons, rods, and upgraded bearings. These components ensure the engine can cope with the additional stress without risking failure.
• Larger Fuel Injectors and High-Flow Fuel Pump: To support the increased power levels, you will need to upgrade the fuel system. This typically involves fitting larger injectors and a higher-flow fuel pump to ensure the engine receives sufficient fuel.
• Upgraded Cooling System: As power increases, so does the need for effective cooling. At Stage 3, a larger chargecooler and possibly additional oil and water cooling systems will be necessary to keep temperatures under control during high-performance driving.
• ECU Remap and Custom Tuning: With all these hardware upgrades, the ECU will need a custom remap to ensure all components are working together optimally. A custom tune will be tailored to the specific setup, ensuring the car is running at its maximum potential.

Stage 3 tuning will undoubtedly push the A45/CLA45’s performance to extreme levels, but as mentioned earlier, the costs can rise significantly. In addition to the parts, the labour and expertise required to fit and tune these components can add up quickly.

Conclusion

Tuning your A45/CLA45 W176/C117 is an exciting way to unlock more performance and enjoyment from these already impressive vehicles. The tuning paths vary depending on how far you want to go with your upgrades, and each stage comes with its own set of costs and benefits.

• Stage 1 provides a modest increase in power with minimal investment, perfect for those who want a noticeable performance improvement without major changes.
• Stage 2 offers more significant gains and involves upgrading key components like the downpipe, chargecooler, and intake, along with a remap.
• Stage 3 is for those who are looking for maximum performance and are willing to invest significantly in engine and turbo upgrades, along with supporting modifications.

Each tuning stage offers different levels of performance, and the best option depends on your goals and budget. Whichever path you choose, remember that proper maintenance and professional tuning are essential to ensure reliability and performance after any modification.