Is your 2.3L manual? There is a big difference between automatic and manual in our 2.3L, I have manual and I test drove an automatic 2.3L before, it feels slow. If you have automatic, I doubt you can beat his 1.8T if he has manual.
I have faith in the 6 but I don't really know anything about the passat so you could just race him for kicks since he is your friend but def. let us know the outcome
since it seems, given no mention of times, you are talking about street racing (no matter how controlled) your friend, gotta close it.
most of the info is out there somewhere already, so i suggest 1)searching around for more info and getting your own conclusion 2) find someone with a similar car setup and PM them if they have any experience with certain cars 3) learn how to word threads so it doesn't look like street racing