Mercedes C63 AMG W205 Tuning Guide

The Mercedes-Benz C63 W205, with its 4.0-litre twin-turbocharged V8, is a highly capable performance car that can be further enhanced with tuning. Whether you’re looking for a modest increase in power or a full-scale upgrade, tuning a C63 W205 can unlock substantial gains in performance. This guide focuses on Stage 1 and Stage 2 tuning, offering a practical approach to improving the car’s output without delving into the more complex and costly Stage 3 modifications.

Check out our wide range of available tuning parts for your W205 C63 here!

Stage 1 Tuning: Software and Simple Upgrades

Stage 1 tuning is the most straightforward option for boosting the performance of your C63 W205. At this stage, the tuning process typically involves remapping the ECU (Engine Control Unit) to optimise the engine’s performance, as well as a few minor hardware upgrades. Stage 1 is a cost-effective way to unlock more power and improve throttle response, without the need for significant hardware modifications.

ECU Remap

The primary upgrade in Stage 1 tuning is the ECU remap. A remap optimises the engine's parameters, including fuel delivery, ignition timing, and boost pressure, to increase power output. On the C63 W205, you can expect an increase in power of around 50-80 horsepower, depending on the tuner and specific settings. This upgrade is typically safe and reliable, as it doesn't push the engine beyond its standard capabilities.

• Power Gains: 50-80 horsepower (up to around 530-560 horsepower in total)
• Torque Gains: Typically 100-150 Nm, leading to improved low-end power and throttle response.

Sports Exhaust

While not strictly necessary for Stage 1, a sports exhaust system can complement the ECU remap by improving the engine’s breathing, increasing the car’s overall performance, and enhancing the sound. An aftermarket exhaust system with less restrictive catalytic converters or a performance muffler can slightly improve airflow, reducing turbo lag and improving power delivery.

• Power Gains: Minor increase in power (5-10 horsepower)
• Sound: A more aggressive exhaust note that enhances the driving experience.
• JXL Performance recommends the Milltek Sport Exhaust system

Air Intake System

An upgraded cold air intake can also be part of Stage 1. It allows the engine to draw in cooler, denser air, which can improve combustion efficiency. While the gains are modest at this stage, it helps with overall engine responsiveness, particularly at higher revs.

• Power Gains: Around 5-10 horsepower
• Benefits: Improved throttle response, better turbo spool-up.

Stage 2 Tuning: More Power, More Hardware

Stage 2 tuning takes things a step further, requiring more significant hardware modifications that help the engine perform even better under higher power loads. This stage is designed for those who want more power without going to the extreme of Stage 3. The key to Stage 2 tuning is upgrading components to support higher boost levels, better airflow, and enhanced fuelling.

Upgraded Downpipes

One of the most important upgrades for Stage 2 is the installation of high-flow downpipes. These larger-diameter pipes reduce exhaust backpressure, allowing the turbos to spool more freely and produce more power. A less restrictive exhaust system enables the turbos to perform more efficiently, contributing to a noticeable power gain.

• Power Gains: 20-30 horsepower
• Torque Gains: 40-60 Nm
• JXL Performance recommends the Milltek Downpipes here

Chargecooler Upgrade

With higher boost pressures from Stage 2 tuning, the temperature of the intake air will rise, which can reduce engine efficiency and power. Upgrading to a larger, more efficient chargecooler reduces intake air temperature, preventing heat soak and helping maintain power output during hard driving.

• Power Gains: Indirect improvements, but essential for reliability at higher power levels.
• Benefits: More consistent power delivery and reduced risk of heat-related performance drops.

ECU Remap (Revisited)

With Stage 2, the ECU remap is revisited and recalibrated to accommodate the new hardware. This ensures the engine is running optimally with the upgraded downpipes, chargecooler, and other modifications. The mapping will adjust boost levels, timing, and air/fuel ratios to ensure the car performs reliably without causing damage to the engine or drivetrain.

• Power Gains: 80-100 horsepower (up to around 600-620 horsepower in total)
• Torque Gains: 100-150 Nm

Stage 3 Tuning: Beyond Stage 2

Stage 3 tuning involves a significant overhaul of the car’s components and is typically aimed at achieving much higher performance levels. This stage can include replacing the turbos, upgrading the fuel system, reinforcing the engine, and further tuning the ECU. However, Stage 3 comes at a much higher cost due to the additional hardware required.

The key components for Stage 3 include:

• Upgraded Turbochargers: Larger, more efficient turbos can significantly increase power output but will require supporting mods such as a high-flow exhaust, upgraded chargecoolers, and more aggressive mapping.
• Fueling System: Larger injectors, high-pressure fuel pumps, and fuel management systems are necessary to supply the engine with the right amount of fuel.
• Engine Reinforcement: If pushing towards 700+ horsepower, internal engine upgrades, such as stronger pistons, rods, and potentially a reinforced block, may be required to handle the extra stress.
• Transmission and Drivetrain: With higher power levels, the drivetrain may require upgrading, especially if you want to ensure long-term reliability.

Stage 3 Cost Considerations

Stage 3 tuning typically runs into the tens of thousands of pounds due to the amount of hardware involved. It’s worth considering the end goal of the car and the budget, as this stage is suited for those seeking very high power and track-level performance.

Conclusion

Tuning your Mercedes C63 W205 is an exciting way to unlock more power and performance from an already impressive vehicle. Stage 1 tuning is an excellent option for those looking for moderate gains and a more responsive driving experience, while Stage 2 tuning offers a more substantial boost with the addition of key hardware upgrades. Stage 3 tuning provides extreme performance but comes at a high cost due to the extensive modifications required.

Before starting any tuning project, it’s important to consider your end goals, budget, and the reliability of your vehicle. Tuning should always be done by reputable professionals who understand the delicate balance between power and engine longevity.