ECU varies the boost pressure using Pulse width signal (WDGC) along with temp changes/atmospheric pressure to provide linear boost curve and cut the boost in-case of failure. There 10-12 WGDC tables and 5-6 Boost tables to tweak the desired boost at various RPM levels. ECU controlling the Target Boost: Person driving around 70% throttle at 4000rpm hits 17psi ECU checks the WDGC with 50% signal. With 50%, boost is 12psi. Lets assume. ECU now calculates it needs 5psi more and adds more duty cycle. Probably at around 60-65%, ECU reaches to 17psi as desired. During this time, if driver rises/releases the throttle then again New Target Boost is desired. Again the ECU recalculates all over with above sequence. This way ECU tries to provide steady boost across the RPM based on throttle position. Within these calculations, ECU also massages few numbers based on air temp/rpms/specific gears etc to reduce the turbo lag. Pulsing Signal from ECU is controlled in WGDC tables. WGDC maintains % of how long the actuator is open within the normal operating frequencies More % of WGDC open = more air is fed to the system and delaying the wastegate from opening WGDT is operated on a square wave frequency. 0% WGDC = Low Boost 100% WGDC = Max Boost During the process of exhaust gases and turbines/compressors running, catalytic converter plays important role. CatCon acts like Exhaust Restrictions which would directly impact the WGDC & Boost tables. It means, to correct the WGDC/Boost tables the tuner has to fiddle around Exhaust Cam Timing Maps/Ignition Timing Maps/Compressor Maps/Min & Max WGDC maps/Desired Boost Maps etc. During these tweaks, the equilibrium has to be found to keep the Knock correction maps stable across the turbo band as desired by factory settings. These limitations forces some of the tuners to go for MBCs. Removing CatCon makes this equation much more complex for tuners to play around. That too here we are talking about FGT engine which has wastegate actuators. No vanes as in case of VGT. Till now I have not come across tuners who has tweaked the Boost/WDGC tables to increase the boost levels. Using MBC is not an offence/mistake given the expectation from it is kept limited to the usage of the engine/turbo setup. Goal: We all want more power with minimal investments to achieve the desired swoosh effect. This is never ending enigma for every enthusiastic driver to make his car performance oriented within the limitations of the engine setup. sample table of WDGC for reference.