That is being done is Europe somewhere, the dude probably found an rs6 engine and thought it would be fun to do. RS6's are heavy and like I said automatic only so this will be a lot more fun to drive than an RS6. Those engines chipped make about 520hp crank. I dunno, its not something I would do, a healthy stage 3 s4 can do that, but throw a couple of gt28s on the RS6 and shit would be crazy, even more so if the motor is in a manual A4