You can do the supporting mods (dv, filter, turbo-back exhaust) first with no problem. Might want to upgrade your intercooler too (see the DIY forum on the $150 front mount intercooler). When it's time for the big turbo, you'll need the bigger injectors to safely fuel its increased airflow, and to run bigger injectors, you'll need the ECU remap, so you can do the turbo, injectors, and ECU together as one step, after you do the first parts.

 

thx alot, u think my shop would reflash my ecu i have already??? isntead of getting another?

 

Yes, they should be able to reprogram your existing chip, probably for a small fee (I got my initial ECU upgrade for the Z for $300, and then when I got it remapped again later on, it was $50 additionally). There's probably a similar arrangement on the Audi chips - I'd hope so at least.