Kline Innovation Turboback Exhaust System for 991.1 Porsche 911 Turbo S

Kline Innovation Turboback Exhaust System for 991.1 Porsche 911 Turbo S

In its seventh iteration, the 911, known as the 991 Turbo S, has embarked on a visually captivating evolutionary journey. Notable enhancements include a broader wheelbase and improved axle-to-engine geometry, which contribute significantly to weight distribution and cornering stability. The integration of additional composites and aluminum further reduces the overall weight of the vehicle. Even the exhaust system has undergone notable improvements compared to its predecessor, the 997. Now, the question arises: How much room is there for improvement over the factory exhaust? The answer is quite simply remarkable!

The Sound

• Capitalizing on the design innovations and successes of their 996 and 997 range, the development of the 991 Turbo S exhaust aimed to meet the highest standards. Incorporating their trademark perfect x pipe geometry, harmonically tuned silencer geometry, the utilization of Inconel 625, and proprietary acoustic silencer packing materials, the resulting system has become renowned for its signature sound. It boasts zero drone and delivers a captivatingly elevated pitch that transforms into a thrilling howl at higher RPMs and under aggressive throttle. This design is so exceptional that even the race versions can be driven silently at cruising speeds, reserving the unleashed howl for intense driving moments.
• During the development process, the team identified clear evolutionary design steps to integrate. One notable addition was the secondary tailpipe, which allowed for the incorporation of an effective gas overflow system. This concept was conceived during the fluid dynamic modeling stage and effectively reduces low RPM noise while enhancing cross-sectional area at higher RPMs. The result is a more accentuated Jekyll and Hyde personality and slightly broader torque curves.

Performance

• The exhaust system is offered with two options for enhanced performance and sound: racing pipes and 100 or 200 cell HJS HDPE catalysts. Opting for the racing pipes provides the most significant gain, offering an impressive increase of 38hp and 55nm. Alternatively, the 100 cell and 200 cell catalysts deliver respective power gains of 20hp and 16hp.

Stainless Steel

• In the realm of exhaust manufacturing, the prevailing industry standard revolves around the utilization of 304-grade stainless steel. This specific grade of stainless steel offers a well-balanced combination of moderate strength, thermochemical stability, cost-effectiveness, and ease of production. It enables the fabrication of exhaust systems that strike a sensible balance between affordability and functionality, guaranteeing enduring durability. However, it is worth noting that stainless steel is relatively heavier compared to alternative materials. Although it shares a similar density with regular steel, it possesses slightly lower tensile strength. This limitation curtails the potential for creating high-performance exhaust components using stainless steel. Moreover, in terms of sound characteristics, the thicker sidewalls required by stainless steel may result in a somewhat subdued and less vibrant exhaust note compared to the aforementioned materials.

Inconel

• When it comes to ensuring durability and heat resistance in the aerospace industry, the utilization of Inconel 625 takes precedence. This exceptional material finds extensive applications in the production of critical components, particularly exhaust turbine blades for high-performance jet engines. Notably, Inconel is the preferred choice for Formula One exhaust systems and has been selected by manufacturers involved in prestigious hypercar projects such as the McLaren P1 and Aston Martin 177. These applications greatly benefit from Inconel’s exceptional capacity to withstand extreme temperatures exceeding 1000°C while emphasizing lightweight design.
• Inconel exhibits extraordinary properties, including remarkably high tensile strength and outstanding thermochemical stability. Its tensile strength is comparable to that of titanium, resulting in an exceptional strength-to-weight ratio. Consequently, Inconel allows for the utilization of thin sidewall materials while preserving structural integrity, facilitating the production of lightweight components that demonstrate remarkable resistance to fatigue over extended periods. However, working with Inconel poses certain challenges due to its difficult machinability and specific welding requirements, demanding specialized skills and time-consuming techniques. Additionally, the unique properties and specialized manufacturing processes associated with Inconel contribute to its higher cost as a raw material.

Carbon Fiber

• With an outstanding tensile strength to weight ratio surpassing that of all metals, carbon fiber reinforced polymer exhibits remarkable properties. Its lightweight nature and impressive tensile strength enable the molding of components into virtually any desired shape. The company exclusively employs aerospace and Formula 1 grade pre-preg carbon fiber, which undergoes a meticulous curing process in an autoclave under high pressure and temperature. This rigorous procedure ensures the production of carbon fiber that is not only exceptionally strong but also remarkably lightweight, making it the perfect choice for even the most demanding and extreme conditions.

Specifications

• Cross Sections:
  • Racing Pipes Cross Section: 76mm OD (specifically chosen for a balance of peak torque and power)
  • Silencer Section & Cross Section: 70mm OD & 63.5mm OD overflow
  • Catalysts come in a variety, from 108mm OD to 127mm OD
• Materials:
  • Turbo Back System:
    • 304 Grade Stainless Steel:
      • 200 cell cats: 14kg
      • Racing pipes: 12.5kg
    • Inconel 625 Formula One Grade Material: 7.5kg
  • Manifolds:
    • Standard 304 Grade Stainless Weight: 6kg total
    • Inconel 625 Weight: 2.9kg total
    • Equal length design
  • Tails:
    • Available in Aerospace grade carbon fiber

Applications

• Porsche 911 Turbo S: 991.1 (2012-2016) – 3.8L TT Flat-6

Notes

• While the images showcase carbon fiber tips and manifolds, it is important to note that they are not part of the standard package

About Kline Innovation

At Kline, exhaust design is approached with utmost seriousness. The company adopts a no-compromise stance when it comes to delivering a product that meets the highest standards and satisfies customers’ expectations. Kline offers a comprehensive original equipment design and manufacturing service. Starting from provided drawings or design briefs, the team utilizes advanced 3D modeling techniques to create final designs. They also provide valuable consultation during the process and are capable of manufacturing tooling and fixtures for production, as well as handling final production runs, particularly catering to low to medium volume needs. Kline’s commitment to excellence ensures that customers receive a top-quality product without any compromises.

Development

• All projects at Kline are executed entirely in-house, utilizing a diverse range of processes. These internal capabilities include laser scanning, CNC laser cutting, CNC mandrel bending, tubing and silencer manufacturing, CNC welding, pressings, CNC milling, mould manufacturing, and autoclave carbon fiber production. Notable automotive clients, such as W Motors with their Fenyr Supersport, Corbellati Missile, and RUF Automobil, have recently collaborated with Kline.
• Kline has expanded its design and manufacturing process by incorporating laser scanning capabilities. This valuable addition enables the team to achieve enhanced precision in both design and quality control, resulting in an exceptional end product for customers. The adoption of laser scanning technology at Kline showcases the company’s unwavering dedication to delivering superior outcomes.