Let me preface this post by saying that I have not read through all the 33 pages of this thread so I apologize if what I say has already been brought up.
I have been a car enthusiast my whole life and have been into modding cars for many, many years. I am now 46, and this started at age 17, so what I say comes from years of personal experience and knowledge.
So here are my points:
1. When you add forced induction to an otherwise stock NA street motor, you are playing with fire. No if, ands, or buts. Your risk of engine failure will go up. If there are inherent weaknesses in the motor to begin with, adding FI will make it much more likely that those weaknesses become exposed.
2. Your margin for error while driving becomes much less. While a mis-shift, an over rev, etc, etc, may be tolerated by a stock motor, it may not be by the boosted motor.
3. Over the years I have seen blown motor after blown motor on all sorts of cars with all sorts of kits. Sure it can happen on a stock motor too, but the risk is just that much higher when boost is applied to a previously NA stock street motor.
4. If you want to go forced induction, buy a forced induction car from the factory. I guarantee you that the tolerances for the internals are such to allow a huge increase in tuned power without much worry. A stock B5 Audi S4 which came from the factory with a 250hp twin turbo V6 could be easily tuned for over 450hp and almost 500lb-ft of torque on the stock block with bullet proof reliability.
5. If you want to put FI onto a NA street car, you need to build the motor...crank, pistons, rods, rings, and run a CR of certainly less than 10.5.
Do it right or don't do it at all. While I feel for the OP, let's be real. Is anyone really surprised that this happened? I hope not.
Audi S6 * Audi S3 * Porsche Cayman GTS
--Former BMW M3 owner