The naturally aspirated v6 was a dog to drive. The car drove smooth, was comfortable and quiet but that's about all it had going for it. It would serve a middle aged mother of 3 just fine but the body lines, color, and all wheel drive setup screamed to be modified. Looking at some examples of what the B5 can look like when tuned up explains everything:
There were multiple paths I could take to get where I wanted, the first and easiest was to perform the standard intake and exhaust modifications but that would only net round 200hp (this was before the chip existed). Some recommended swapping in a S4 2.7 engine I nixed this due to extreme cost of going to the s4 motor and then having to modify it further to reach my goals. Others said go to a 1.8t, but the idea of going to a smaller engine seemed counter productive especially since it would have to be modified further also. One suggestion that I had got was to swap in a small block chevy engine. I actually tossed this idea around for a while but couldn't bring my self to tarnish the poor car with a domestic engine, not to mention the electronics nightmare of mating a German car with an American engine and hell will freeze over before I would ever put a carburated engine in such a nice car. From the get go everyone in the Audi community advised against starting with a 12 valve engine if you wanted more than a few hundred hp. Everyone thought that it would be prohibitively expensive. Being stubborn I decided to just ignore them all and work with what I had.
The best thing about using a platform that no one else wants is parts availability. Before there were other engine options, certain aftermarket companies made a handful of performance parts for this motor. Now that other people are using all sorts of more "acceptable" engines, these parts can be had at a fraction of the original cost. Eurospec cams for example were $1100 new, I lucked out and got them for $250, an Unorthodox Racing billet aluminum 10lb flywheel; new they cost $550, I found one used for $200.
Conversely, parts availability is also the worst thing about using a platform that is older. Yea I found some great deals on parts like the flywheel, but that flywheel also took me 6 months of searching to find. There is a saying about food that you can have it fast good or cheap but you can only pick two. The same goes with car parts. You can get good parts fast but you'll pay full list, by exercising some patients you can find good parts cheap but not fast. Never get cheap parts fast, its not worth it, eventually they will break and you will have to replace them. When I say patients, I mean it. It took me 4 years to collect all the parts I needed. By having it as a casual hobby you give yourself plenty of time to plan, learn, and buy things as your finances allow. I have seen people slap projects together in a hurry but they usually dont end up working right, taking time to plan is the key to a successful project.