Case Study | Audi RS 7 (C7)

The C7 Audi platform has been one of our all-time favourite street cars. Since our purchase in 2015, our Audi RS 7 has been a cornerstone of our development and showcase efforts at PERON. It has been run on our in-house dyno and reflashed hundreds of times, allowing us to refine and perfect our tuning and hardware solutions while living and breathing the platform. This vehicle, still running exceptionally well as a daily driver, was initially acquired to demonstrate the capabilities of PERON and our engineering partners. Through this journey, we have mastered the intricacies of the 4.0 L engine, making it a true testament to our commitment to excellence in automotive engineering, with every upgrade and solution being completely optimised for maximum confidence and performance.

The Brief

Our mission was to fully master the Audi RS 7 C7 platform, elevating it into the supercar realm with precision engineering and selective hardware upgrades. This wasn't just about increasing power; it was about enhancing the acoustic presence and drivability whilst maintaining the comfort expected from an executive saloon.

To achieve this, we focused on integrating bespoke performance upgrades and meticulously calibrated tuning stages. Our goal was to offer tuning solutions that catered to various performance desires while introducing key hardware enhancements along the way. By refining every aspect of the vehicle, we aimed to create an Audi RS 7 that represents the pinnacle of what the factory could have achieved, combining high performance with refined drivability, all while respecting the vehicle's age and ensuring its long-term reliability.

Ultimately we sought to create one of the best daily drivers this side £50,000.

Our Results

Each of our tuning stages was developed to enhance the vehicles performance and drivability by combining our ECU/TCU calibrations with selected hardware upgrades. Starting with Stage 1, we refined drivability and power output while staying within the limits of the stock hardware. Stage 1+ introduced intake enhancements to allow the vehicle to breathe more freely and increase its power output effectively.

Moving on to Stage 2, the RS 7's transformation became more pronounced with the integration of Nortech Performance high-performance downpipes, significantly improving exhaust flow and heat management. This stage not only increased the engine's power but also amplified the vehicle's exhaust note, creating a more aggressive and engaging auditory experience. The final step in our stock turbo tuning process, Stage 2+, adds the Akrapovič Evolution Line to complete the exhaust system upgrade and further improve acoustics. Stage 3 introduces larger turbochargers as well high pressure fuel pumps as the stock turbos and pumps are at their performance limit by Stage 2+. This increased air flow capability allows for much higher peak power figures.

  • Stage 1: 560ps cars: 640-650 hp | 605ps cars: 650-660 hp
  • Stage 1+: 560ps cars: 650-660 hp | 605ps cars: 660-670 hp
  • Stage 2: 560ps cars: 670-700 hp | 605ps cars: 700-710 hp
  • Stage 2+: 710-730 hp
  • Stage 3: 750 - 800 hp

Establish Baseline and Identify Areas for Improvement

Our first step was to rigorously test the vehicle on both our in-house DynoJet 424x linked dyno cell and on the road to establish a baseline of the car’s performance capabilities. With this car being used as a daily driver since 2015, we have accumulated many hours of seat time and real-world driving experience. By assessing the vehicle under controlled conditions and real-world scenarios, we identified several areas for improvement.

The factory engine calibration was overly conservative, leading to inconsistent drivability and unresponsive power delivery, despite the fairly high stock power figures. Audi's factory transmission calibration was lacking with sluggish response and lazy shifts. The air intake system was restricting the engine's ability to breathe freely, the exhaust system was too restrictive and muted the engine’s potential sound. Our initial performance assessment highlighted how ambient conditions, fuel quality, and mileage can affect individual car results, with tuning and testing notes indicating that intake and ambient temperatures significantly impact performance.

Engine Control Unit Calibration (ECU)

The calibration focus is always to improve the driving experience as safely, and consistently as possible. To that end, our ECU calibration not only increases power and torque but also enhances engine smoothness and response. This is done through changes to throttle maps, turbo pressure, fuel delivery, ignition timing, camshaft timing, cooling strategies, plus many other controlled variables. We also introduced changes to the factory overrun to add more 'pops and bangs', giving the driving experience a more aggressive edge.

Utilising the advanced capabilities of Dyno Spectrum DS1, we enable map switching, high-speed data logging, and FlexFuel integration, providing unparalleled flexibility and precision. Our optimised tuning stages range from Stage 1 with stock hardware to Stage 3 with larger turbos, complemented by intake and exhaust hardware from Stages 1+ and 2, achieving supercar-rivalling performance.

About Dyno Spectrum DS1

Transmission Control Unit Calibration (TCU)

Alongside the comprehensive ECU recalibration, the TCU was finely tuned to align perfectly with the newfound engine performance. The TCU adjustments began with an increase in 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 which enabled 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, maximising efficiency and responsiveness. This tailored approach to the transmission settings ensures that the RS 7 delivers a dynamic yet smooth driving experience, reflecting the best of both worlds in terms of performance and comfort. Key highlights include sensibly increased torque limits, increased pressure for higher torque capacity, optimised upshift and downshift points, and faster, smoother shifts in all conditions.

Performance Hardware

For the Audi RS 7 (C7), we strategically selected performance upgrades to optimise power and improve the vehicle's acoustic profile. The upgrade began with an ITG Panel Filter, which reduces pressure drop in the turbo inlets to improve air delivery and engine responsiveness. To ensure ignition efficiency, NGK Racing Spark Plugs were installed. These provide more consistent ignition performance at increased power levels.

The exhaust system saw significant enhancements with Nortech Performance high-performance downpipes, designed to reduce backpressure and enhance exhaust flow. The reduction in back pressure improves turbocharger efficiency and moves heat away from the engine compartment. The downpipes are paired with an Akrapovič Evolution Line, noted for its aggressive sound, improved exhaust flow and reduced weight. These performance hardware upgrades work together with the ECU and TCU calibrations to create a optimised package that is greater than the sum of its parts.

Future Upgrades

After adding larger turbos and increasing air flow capacity, the next step is to enhance the fuel system to support flex fuel applications. Running a flex fuel setup with ethanol allows for higher performance due to ethanol's superior cooling and anti-knock properties, enabling more aggressive tuning. Additionally, integrating water methanol injection can further assist with cooling, providing an extra layer of performance enhancement by reducing intake air temperatures and preventing detonation. These upgrades will push the RS 7's performance capabilities even further, ensuring it remains competitive with the latest supercar offerings.

For those looking to push power levels even higher, a forged engine would be the next stage of progression.