Audi never brought the TT TDI to North America. So someone decided to change that by building their own. They started with a 2003 Audi TT Quattro and swapped the factory turbocharged 1.8 L inline-four for a turbocharged 1.9 L ASZ (PD130) diesel inline-four from a 2003 VW Golf GTD. The diesel motor features Colt Cams Stage 2 camshaft, black nitrided lifters, BEW injectors with Bosio Power Plus 1043 DLC PD nozzles, and 42 Draft Designs exhaust. It produces 180 hp and 340 lb-ft of torque. The owner retained the six-speed manual transmission however with a DRW gearset, Sachs clutch and flywheel, and Neuspeed short shift kit. The Quattro AWD was upgraded with heavy-duty front axles.
Source: Cars & Bids via Carscoops
Why do this though ??
Because a TDI has a lot of torque and that lends itself well to this chassis from a fun standpoint.