Hi vwgtiking,
What happened to your BFB set up? Are you ditching the stock turbo and going with the BBT upgrade? Which turbo are you going for?
I too have the BFB engine in my 05 Cab. This is actually a KO3's turbo. Funny thing is the term 'KO3, KO3s and KO4 is coined by tuners and not 'BorgWarner', the makers of the turbo.
To answer you previous post if you didn't receive a response is that the BFB engine with 163bhp as stock can go to about 230bhp max really with full supporting mods. Decat, Straight through exhaust, FMIC. Not to mention injector upgrades, Piper cross panel filter, TIP etc.
To put things in perspective my mate maxed out on his A3 1.8t with KO4 swap. He was getting about 265bhp with FULL supporting mods even forged conn-rods. This was the safe limit suggested by the tuner.
Hope that helps.