A friend and I are in the process of building a twin turbo "kit" for my '96 328is. I had the turbos sitting in the garage and he can fab up the manifold for only the cost of materials so you can call me stupid all you want, I'm still doing it lol. The only problem I'm thinking about is whether or not the turbos are too small. The turbos I have are Borg Warner K03s out of my Audi S4 left over from going stage 3 on it. I'm assuming that they will run out of breath at around 450 crank horsepower on the BMW, since they are pretty much maxed out on the 2.7 in the Audi at about the same number, am I right or am I overlooking something? Can anyone tell me how to read a compressor map in relation a twin turbo setup? Is it as simple as cutting the engine's airflow in half?