Motor Werks Racing builds Porsche 944 race cars with a turbocharged 1.8 L Audi inline-four. Or you can build your own Audi 1.8T powered 924/944 using their swap kit. The company will also swap the same motor in a Porsche Boxster. Last year they built a Boxster 986 for the track with one of these motors and a five-speed manual transaxle. Listen the car running in the videos below.
Source: Motor Werks Racing