I have been looking at wastegate control. I was hoping to use the ECU in closed loop mode which would have been complex to configure but would have meant precise control. Unfortunately it seems the base model ECU I have can't do closed loop but is limited to open loop. In the configuration help file it seems to control the wastegate on a throttle position versus rpm basis with no account of the actual boost value. I emailed David from Tune Technic who I bought the ECU from and he came back with a suggestion to put Manifold Gauge Pressure(MGP) on one table axis and RPM on the other. The table values are the amount the wastegate is opened effectively. To me this makes it more or less closed loop. Values are entered in the table below the desired boost that result in the wastegate remaining closed. As boost approaches the desired value the table entries result in the wastegate progressively opening. The boost control solenoid has a pulse width modulated(PWM) signal applied which opens a bypass valve an amount depending on the pulse width. Failsafe mode is fully open which will pass manifold pressure to the wastegate without restriction. I can see this working really well with the wastegate closed until boost closely approaches the desired value. This will assist with spool up. I know with my big bike that this can really help. With boost on the big bike set to 12lb the turbo spooled up a bit slower from about 8lb. With the wastegate set for 19lbs boost the turbo spooled up to 14-15lbs really quickly as the wastegate was completely closed until then. Fun day at Taupo running 19lbs boost. The front wheel would not stay on the ground over 6000rpm in any gear.
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