At first glance, there isn't much to differentiate the B6 Audi A4 from the S4 besides aluminum mirrors, lower door trim and badges. Of course the wheels, brakes and interior are slightly different but in the tuning world, enthusiasts commonly change up these parts anyways, so the distinction of Audi's flagship S model can easily be lost.
That is until you pop the hood and feast your eyes on the engine within. It was a controversial move by Audi to ditch the successful and highly-tuneable 2.7L twin-turbo V6 from the B5 S4 for the 4.2L V8 in the next generation S4, but enthusiasts like Carson Yang embraced the change.
"All I wanted was either an Audi A4 1.8T or 3.0 but my girlfriend wanted better so I went with the 4.2 liter instead," Carson grinned.
Trunk illuminates blue to...
Trunk illuminates blue to show off JL Audio subs and Audison amps
"I really liked everything about the car. I just wish its MPG were a little better!"
Five years ago, Carson picked up this brand new '04 S4. It was his first project car and he didn't know what to do with it. Like angels on his shoulder, renowned car club TWCompetition came to the rescue and introduced the young equity trader to a network of enthusiasts and industry connections. "I received a lot of advice from them such as choosing HRE, Brembo and Oettinger parts - I couldn't go wrong with any of those companies," he explained.
Carson started his S4 project by tastefully personalizing the exterior. For a noticeably more aggressive appearance, he installed the entire Oettinger package, which included a front valance, side skirts, front grille and roof spoiler. An Oettinger valance was also molded to the rear bumper to match the OE styling.
The most extravagant ingredient was the new paint. The car was formerly Dolphin grey but after a vandalism incident, Carson had the car sprayed in Porsche Seal grey which "has more pearl in the paint," he elaborated.
Another visually-stunning aspect of the S4 was the wheel and brake combination. A vivid set of five-spoke 19x8.5" HRE 545R wheels complemented the massive front and rear Brembo big-brakes. Because switching to a rear big brake kit sacrificed the factory e-brake mechanism, Carson used Brembo components to retrofit a workable handbrake.
Undoubtedly, the biggest difference between the A4 and S4 lay under the hood. Equipped with a 4.2 V8 rated at 339hp, the S4 summons more power than a stock BMW E46 M3. With so much power already available from the factory, Carson didn't care to change much. He installed a LaBree dual cat-back exhaust with downpipes to unleash the roar of the eight-cylinder motor. GIAC software and a Stratmosphere intake system gave the motor even more usable horsepower and quicker throttle response.
The last piece of performance added was the KW Variant 3 coilovers, which allow the suspension to adjust in height and damping. H Sport sway bars ensured body roll was also kept to a minimum.
These three monitors on the...
These three monitors on the trunk lid are configured to play independent or the same video outputs
Stepping inside, Carson kept the interior refined and luxurious. Not wanting to lose the classiness of the S4, the leather OE Recaro seats were reupholstered in Silk Nappa black and grey suede. The headliner, pillars and rear deck were also reupholstered in suede, while factory carbon-fiber pieces from Europe were sourced for the trim.
There's no arguing Carson had built a fine automobile, but the electronics are what truly put this Audi on another level. Carson was absolutely meticulous about the audio. "I had to redo the audio three times until it came out the way I liked it," he revealed.
The original head unit was ditched for an Alpine flip-up 6.5" touchscreen monitor. It controlled the professional-quality Audison two-way speakers and JL Audio 10W7 subs with a pair of Audison amps powering the entire stereo.