I saw this vid a while ago what you are seeing come out the back is molten copper head gasket....its nasty stuff. Also if you listen the its running a powerglide tranny. Good choice for a turbo that big, you can preload the turb to cut out the lag then there is no spool down between shifts. What you are watching is a 2nd gear pull its going to be one of the most acurate pulls around beacuse in 2nd a powerglide is a 1:1 gear ratio so the oly change in gearing from the engine comes from the rear end.
Ok i will stop talking nerd and say this....nice vid I want a turbo that big on my VW