[porsche_fan]

hey there,

great write up and a handy quick reference document.

Would like to add a few comments,

1.) Since the torque produced by the engine is going to increase, one needs to just confirm whether the gearbox 'll be sufficient or not.
2.) You'd also need to check the end connections from your manifold and need to select a housing that matches the same. Also you need to check if there is a flexible pipe between the turbo outlet and the rest of the exhaust system. This helps in relaxing the thermal loading of the system.
3.) Most important and as has been pointed out before, is to be clear of your objective is. with the turbos available today for petrol engines it is'nt possible to get both good low-end torque and high-end power. To put it simply, its like this; (This mainly applies to internally WG turbos)

There is a performance characteristic that is specified for the turbine housing of any waste gated turbos. this is the A/R value. Simply put, this value determines the amount of flow your turbine can handle.And since our turbine drives the compressor that provides the boost, its very important to select this value carefully. A very small A/R gives you less lag and more low end torque, but will not give you much in terms of high end power. A very large A/R gives you less low-end torque and MASSIVE lag, but it'll help you in achieving that dream HP target.

What you need to do is to get the most accurate engine data (basically the flow capacity) that you can find and then sit and determine the best possible compromise......