Basic question about the Wastegate Duty Cycle that the ECM is reporting...

So a 0% duty cycle means that the wastegate is open all the time (maximum bypass of the turbo)? It seems like it's at 0% at idle and increases with throttle depression.
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depends on the boost targets but that is normal. The ECUs boost control is based on throttle position and the ecu is always trying to reach these targets when you have the throttle depressed.

I actually have the boost targets and wastegate duty cycle maps set to Zero up until 60% throttle on the WRX. This keeps boost low and fuel mileage up :-)
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The wastegate won't actually be open, because it will be running whatever wg pressure your spring is set to.
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wgdc's are a function of how hard the ECM is trying to bleed air to prevent the WG from opening. prior to hitting WG pressure (around 12 psi) it doesn't need any help as pointed out by 06rexwagon. post WG pressure is when they really start to be needed. the higher thenumber that is reported/programmed, the more the ECM is trying to bleed air via the BCS to prevent the pressure from hitting the WG. 0 represents no pressure being bled, and 100 repsents the ECM attempting to bleed all that it can.
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I didn't realize there was a mechanical (spring) mechanism for activating the wastegate. So at low PSI (<12), it's always open or always closed?
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closed
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One thing that surprised me from reviewing the logs is that manifold pressure/boost is not related only to engine RPMs. It looks like throttle position is a major factor.

For the stock STI turbo, what engine RPMs allow it to generate full boost? It seems like it must be in the 4000 rpm range...
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it's a function of tps, rpm and how the engine is loaded, which is why it's easier to hit boost in 4th than in 1st
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