LOL, 3" has been around for donkeys :lol:
Not really relevant for a crank driven turbo though. 2.5" is more than adequate.
First post alert! 3" will make power over 2.5". I had a rotrex'd 2ltr(not vw) that made 345whp and my 2.5" system was 20hp down on someone with the same setup.
Nice corrado, what fuel pump are you using? Sorry if it's been stated but have skimmed the thread rather than digested it to the full :)