What: PowerPlus 520 Injector Nozzles
Why: The biggest reason why is because Kerma was out of the PP764s. The secondary reason was that I don't want my car to smoke. While the VNT-17 could probably keep the car from smoking much, the PP520's will reduce fuel slightly, and thus smoke would be reduced. The difference of 5HP and 10 Torque is worth the lack of smoke.
Injector nozzles are really easy to replace, and give the most bang for the buck after a chip. This should really be the second or concurrent upgrade after or during chipping.
There are plenty of other nozzles out there, but generally speaking they have poor quality control and end up sucking worse than the stock injectors. Spend the extra $$ for the "approved" nozzles.
What I would do differently: Originally, I had Sprint 520's on the car. With the upgrade to the VNT-17's, I put in the PP520's... so what I would do differently is start out with PP520's.
Kerma TDI and TDIParts