Audi S4 Agency-Power-Blow-Off-Valve enthusiast car, and as featured in the December 2007 issue of Sport Compact Car magazine, a Torque Factory tuned S4 won a comparison test against several other extreme performance cars.[5]The powertrain detail[2] of the B5 S4 features a 2.7 litre twin-turbo ('biturbo') 90° third-generation V6 engine (parts code prefix: 078, identification codes: AGB, AZB). Detail of the powerplant includes a cast iron cylinder block with two lightweight aluminium alloy cylinder heads. The valvetrain includes 30 valves (five valves per cylinder),[6][7] twin hybrid-driven (timing belt and roller chain) double ov

AgencyPower Agency-Power-Blow-Off-Valve The second generation S4 (Typ 8D), now correctly titled Audi S4 quattro debuted in 1997, with factory production commencing October 1997,[2] as part of the facelifted B5 platform Audi A4 line-up, although it wasn't available in North America until late 1999.In addition to the saloon (sedan), an estate version (wagon)-the Audi S4 Avant, was introduced into the lineup from 1998. Production of the B5 S4 ceased in September 2001,[2] although it was still sold together with the next B6 platform generation through 2002 in North America.Several years after it was sold new, the B5 S4 remains a potent