No more than 18PSI if you wanna keep it safe and reliable with or without intercooler.
You can use bleed valve with the TDI engine although the N75 valve will need disconnecting from the turbo but left plugged into the ecu so not to confuse it,and you need to bleed the boost signal to the ecu so it doesnt go into limp mode when it senses overboost!
A forum community dedicated to Volkswagen T4 owners and enthusiasts. Come join the discussion about performance, modifications, conversions, troubleshooting, maintenance, and more!