Benjamin

Try a GT2559v or bigger, the gt2559v seems to be good up to +270hp for a 1.9tdi, still spooling at 2000rpm, some guys did it on their vw.
The problem with those vnt turbos is backpressure, thats why you better pick up a big vnt, with a 2.4 its even possible to use a vnt32. you could also try an external wastegate to lower the backpressure but i dont know if this will work correct.

i have tried this turbo on an old 1.9td like in a 145, it worked fine, alltough i had engine problems wich was not becouse of to much power. i stopped the project becouse i will buy a house and i have a alfa now. many guys have reached the borderline +250hp with a 1.9, but the chiptuner is a big factor, couple years ago we were talking about a vnt20 wich was to lagy to spool, now they have more knowledge, and they spool under 2000.

thats the perfomance part, but it is still a frontwheeldrive, and in my case, i worked more on my car than driving it (probably becouse i did everything myself also). +250hp and even 300hp is possible, but after all, is it all worth it?

Greetz, Benjamin