Hey smoke!
It's an Aussie Ford FG XR6 Turbo ute. Inline 6 4.0L. Running open loop boost. Very new to Fords, turbo charging and variable cams so I have lots to take in. If you care to enlighten me about the flutter, what should I be looking for as possible 'typical' causes?
On another note, the boost control setup makes no sense to me. I'll try to explain my head space.
On spool up we hold the boost solenoid shut to build boost. Then when desired boost is approaching we vary the duty cycle of the solenoid which sends a pressure signal to manipulate the wastegate opening thereby controlling the system to some desired level of boost. Everything is fine so far...
At this point we have 'some' level of pressure in the signal line between the solenoid and the wastegate actuator and the system is in steady state.
Now at a later point in the pull, I want to increase the boost pressure (for whatever reason). To do this I ask the boost solenoid to open less. I expect the result to be less pressure in the signal line so the wastegate can open less but there is already the higher signal pressure to the wastegate actuator present from the previous control state. It is effectively trapped and will always be acting on the wastegate. I.e I can never bleed off the signal pressure I used earlier in the pull. Am I on track?
Currently plumbed as per the 2 port image as per OEM.
And looking to try as per attached with a 3 port.