boosting a 4-port 13b na

[PercentSevenC]

No, you can't use a TII intake. The bolt pattern is different and you don't have bungs for the primary injectors. You'll need an early 13B intake manifold. There aren't any that I know of that will work with the stock S5 exhaust manifold and turbo as-is. You have to space the turbo away from the engine.

With my Racing Beat sidedraft manifold, the turbine housing and one of the primary intake runners had to be ground down a bit, and that's with about a 1/4" spacer between the turbo and exhaust manifold. It's still very close, but I can't go out any further because the idler arm is in the way (it's pretty tricky getting the turbo in, in fact). I don't know whether an S4 turbo and manifold would be any easier or harder to fit.

The stock top-mount intercooler is pretty worthless. Pick up an eBay intercooler and set it up as a front-mount (or do without if you're cheap like me).