Why is there so much black smoke?

[tdiclubfan]

http://youtu.be/2NVbNrb9u0w

 

[FlyTDI Guy]

Short answer, prolific fuel vs air. I hesitate to say 'over-fueled' but, compared to a stock street car w/OEM tuning, much higher fuel/air ratio. Black smoke is unburned fuel.