Rated at: 496 hp / 434 ft/lbs @ 5 PSI Eaton supercharger kit ECU software flash VF-Engineering chose to supercharge the Audi S4 to improve throttle response and mid-to-top while maintaining the the original Audi quality, smoothness and reliability were the key factors in the design. They have harnessed reliability of Eaton superchargers with their 10 years of supercharging experience and worldwide OEM supply contacts to create the ultimate supercharger system for the ultimate driver??s car. All key components are 100% made in California. This system has been fully road tested and dyno tuned on the Mustang MD500AWD. The Audi S4 supercharger kit is setup at 5.0 psi and create as much, if not more power than similar products running greater levels of boost. VF engineers spent over 12 months testing and developing the Audi S4 supercharger kit. Software flash technology and latest Audi file versions have all been employed to provide the cleanest and most reliable method of software installation. All test cars were put through long term full throttle testing in conditions varying from wet cold climates to hot dry Arizona desert temperature for safe-optimal air fuel ratios and knock activity monitoring. Competently-written ECU software has allowed VF to fully explore the potential of the Audi S4 engine, making over 40% more power in most applications. The unit is positioned in line with the original serpentine belt which is replaced with a longer OEM belt. The key to this design is that the OEM active-spring belt tensioner remains fully functional and eliminates belt slip or the need to manually tension the belt. The supercharger air ducts are custom molded to give an OEM appearance, quality and fit. The incorporated Bosch boost overrun system is designed for smooth off-throttle cruising and deceleration with clean emmissions. The crankcase ventillation system is designed to cope with positive pressure. High flow OEM injectors are supplied to fit as direct replacements without modification to the injector rail. The VF supercharger system remains fully OBD2 compliant and is supported by a 1 year unlimited mileage warranty on the product only.