Case Study | Audi RS 6 (C8)

This PERON Automotive case study exemplifies transforming a super saloon into a supercar rival, blending meticulous enhancements with luxury comfort. Through four tuning stages and integration of components such as Akrapovič exhausts and Garrett intercoolers, we achieved up to 775 hp. Advanced ECU and TCU recalibrations optimised performance across the board, delivering a powerhouse that combines executive sophistication with thrilling drivability.

The Brief

Our challenge was to elevate an already formidable super saloon into the realm of supercars—not just in outright performance but also in acoustic presence, all while preserving the drivability and comfort befitting an executive saloon. Our strategy focused on building upon the robust foundations of the C8 platform, enhancing its capabilities through precise engineering and persistent development.

The key to achieving this transformation was the integration of bespoke performance upgrades and meticulously tailored levels of tuning calibration. This ensured that the modifications not only enhanced power and responsiveness but also maintained the vehicle’s luxury and usability. The ultimate goal was to transform the Audi RS 6 into the pinnacle of what it could have been from the factory, crafting a seamless blend of high performance and refined drivability.

Our Results

The Audi RS 6 (C8) achieved remarkable enhancements across four distinct tuning stages—Stage 1, Stage 1+, Stage 2, and Stage 2+—each designed to cater to varying levels of performance preferences and hardware modifications. Starting with Stage 1, which focused on refining drivability and power output within the constraints of the stock hardware, we progressed to more advanced modifications in Stage 1+ and Stage 2, introducing intake and exhaust upgrades that further amplified power and enriched the vehicle's acoustic presence.

The culmination of our stock turbo efforts, Stage 2+, integrates top-tier components like Akrapovič exhaust systems and Garrett intercoolers, pushing the vehicle's performance to supercar-beating levels while ensuring drivability and comfort remain intact. This strategic approach allows each stage to build upon the last, providing scalable performance enhancements that transform the Audi RS 6 into a powerhouse tailored to the specific desires and needs of performance enthusiasts.

UK's Fastest Audi RS 6 (C8)

Stage 1: 675 - 700 hp | 700 - 750 lb-ft
Stage 1+: 700 - 720 hp | 750 - 800 lb-ft

Stage 2: 725 - 750 hp | 850 - 900 lb-ft
Stage 2+: 750 - 775 hp | 850 - 900 lb-ft

Establish Baseline and Identify Areas for Improvement

To initiate the transformation of the Audi RS 6 (C8), our first step was to rigorously test the vehicle both on our in-house dyno and on the road. This comprehensive evaluation served to establish a baseline of the car’s performance capabilities. By assessing the vehicle under controlled conditions and real-world scenarios, we identified several key areas for improvement.

The air intake system, which was restricting the engine's ability to breathe freely; the intercooling system, which needed upgrading to better manage heat during sustained high performance; the exhaust system, which was too restrictive and muted the engine’s potential sound; and the factory gearbox calibration, which had conservative torque limits and shift strategies that could inhibit the engine's enhanced capabilities. Addressing these core areas was essential to transform the RS 6 into a supercar-rivalling machine while maintaining the sophistication of an executive saloon.

Performance Parts

We installed an Eventuri intake system which is renowned for its efficiency and performance. This system uses advanced carbon fibre construction to ensure minimal heat soak and maximum airflow, significantly enhancing the engine's breathing capabilities. The intercooler system was upgraded with twin Garrett cores, known for their superior cooling efficiency. These high-performance cores drastically reduce intake air temperatures, allowing for denser air charge and thus, more power. Integrating Garrett cores assists in maintaining consistent power output and preventing performance degradation during moments of high-demand.

The exhaust system was significantly upgraded with Nortech Performance downpipes featuring homologated catalysts linked to an Akrapovič Evolution Line Titanium exhaust. This system is designed to reduce backpressure, allowing for a free-flowing exhaust that improves both power and torque outputs. Additionally, the Akrapovič system enhances the auditory experience of the RS 6, delivering a deep, resonant sound that becomes progressively aggressive with higher revs.

Performance ECU Calibration

The engine ECU calibration was optimised to enhance the full potential of the upgraded components. Adjustments to fuel delivery ensured optimal rates for the increased air intake and exhaust flow, facilitating efficient combustion at higher power levels. Ignition timing was fine-tuned to align with the enhanced airflow and fuel mixture, maximizing power output while preventing knock or pre-detonation, critical when running on 99RON fuel.

Modifications to the turbocharger's control software allowed for higher boost levels, significantly increasing power without exceeding the turbocharger’s or engine's safe operating limits. The torque output curves were recalibrated to provide a smoother power delivery across a broader rpm range, enhancing both performance and drivability. Additionally, an optimised cooling strategy was integrated to maintain ideal engine temperatures, ensuring performance remains consistent under various driving conditions.

Performance TCU Calibration

Alongside the comprehensive ECU recalibration, the Transmission Control Unit (TCU) was also finely tuned to align perfectly with the newfound engine performance. The TCU adjustments began with an increase in the torque limits and clutch pressures, enabling the transmission to handle the significant increase in power and torque. This enhancement ensures that the transmission can manage the increased loads without sacrificing reliability.

Further modifications focused on shift dynamics. The TCU calibration was refined to enable faster shift times across all driving conditions, thereby improving the vehicle's performance as well as comfort during both spirited and relaxed driving. Additionally, the shift strategy was optimised to ensure that gear changes are impeccably timed, maximizing efficiency and responsiveness. This tailored approach to the transmission settings ensures that the RS 6 delivers a dynamic yet smooth driving experience, reflecting the best of both worlds in terms of performance and comfort.

Further Scope

Taking performance to the next level involves a few key upgrades, building on the foundations laid in previous stages. The next step includes the addition of larger turbochargers to replace the stock units, which are at their efficiency limit. The upgraded turbos feature larger compressor and turbine wheels, optimised for higher airflow and efficiency, essential for achieving higher power outputs.

To support increased boost levels and ensure engine reliability, a water-methanol injection system can be implemented. This system is critical for reducing intake air temperatures, thus preventing detonation and allowing for more aggressive tuning. Additionally, the upgrade to 4-bar MAP sensors will ensure precise monitoring and management of increased intake pressures, essential for accurate tuning adjustments. Depending intended usage, forged rods and pistons can be used to strengthen the engine for further reliability at high power levels.

Further enhancements also focus on developing a more robust fuel system, capable of supporting the higher demands of upgraded turbos and tuning setups, ensuring the Audi RS 6 (C8) not only matches but exceeds supercar performance standards.