Sounds a lot like what I went through at the beginning of the year after I had my auto rebuilt. Mine felt like it was taking off in third gear and blowing heaps of black smoke. They tried to tell me it was normal for the td5. haha..I told them otherwise. Turned out it was a faulty torque converter.
I have boost box, hybrid turbo, 23 psi boost, larger intercooler and stage 2 tune.

