They exist Check out wikipedia buddy there 20 valves 5 cylinders if they werent that expensive i might do it
Taken Off Wikipedia
The S4 was sold worldwide with a turbocharged version of Audi's 2.2 L (2226 cc)' date=' 20-valve inline-5 engine developing 230 PS (227 hp/169 kW) and 350 N·m (258 ft·lbf) of torque. A 280 PS (276 hp/206 kW) 4.2 V8 became available to European customers as an option. Quattro all-wheel-drive and a manual transmission (six-speed in Europe, five-speed in North America) were standard equipment.
http://en.wikipedia.org/wiki/Audi_S4
the twin turbo comment is probally correct though