Hi can you adjust boost levels on stock turbocharger setup?
Boost levels are entirely controlled by the ECU. The ECU specifies a certain amount of boost and until that amount of boost is actually seen by the MAP sensor the ECU will command the turbo wastegate to stay closed via the N75 unit and wastegate actuator system. Then when the specified amount of boost is met the ECU will command that wastegate to open somewhat in order to keep boost in line with the specified amount as long as the turbo is able to (the small little stock turbo can't make peak boost for long).
These are the fundamentals (at a very high/general level) of how boost control works and it requires changing the ECUs maps and parameters related to this behavior to change the boost strategy. You can only do this if you get access to open-source software that allows you to pull the tables from the ECU with this data and edit it, then upload it back to the ECU.
Otherwise you rely on a trained and reputable tuner who has a software tune to do this for you. No offense, but if you had to ask this question then you should go with a software tune from a company like APR, Integrated Engineering, United Motorsport, etc. REVO Tuning, Unitronic, and GIAC are others but I have been around the block either personally, or via seeing lots an lots of data logs from other cars with them, and the last 3 companies I mentioned often times leave something to be desired from the logs I've seen (especially Unitronic, but I'll leave that for another time).
400BHP / 380CTQ - 2007 B6 Passat 2.0T FSI - Weekend Track Car & Part-time Commuter
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