Discussion and questions related to the course Reflashing
Have not been able to find ANY direction on this. Tuning a Fiesta ST with X47R upgrade. Everything is going well but I have not changed the spring pressure table to account for the upgraded 11psi wastegate actuator from the stock 7psi actuator. I am not sure exactly what needs to be done?
Any guidance would be much appreciated!
Ya...the guides are not helpful in a lot of cases :)
Disclaimer - I have a focus ST, so my WG strategy is different than yours, and I am still on the stock turbo so I have not messed with these values.
I believe however you first will need to scale your x axis, since right now as soon as you pass 18.2lb/min of airflow you are going to be stuck at the last value in your table. I believe what this table is saying is these are the absolute minimum boost pressures (relative, not absolute) that the computer should expect to see at these airflow levels with no interference from the WG (WGDC = 0%).
I am attaching a screencap from HPtuners, I also tune with COBB but I find it sometimes is helpful to read the tips in other software to see how they explain and treat the same tables. One is from an ST stock tune and the other from an RS, just so you can see the differences used on these two cars.
Here is also a good read from an ecoboost etuner on upgraded WG actuators, in this case talking about stock turbo, but depending on how familiar you are with how they work it may have useful info for you:
As a starting point, I would try scaling the values by 1.5 (11psi/7psi = 1.5)
You can also force the WG to stay open by setting your WGDC table to zeros and log your TIP and airflow, and model this to your minimums table (maybe remove a PSI or 2 from the values you get, just to ensure the values you enter are never gone below in real life...this is supposed to be a minimums table after all.)
Hope that helps...
I don't know the exact details of how that minimum works. Do either of you know: Is is it used for torque limiting (throttle closures) ? Is it used for some kind of OBD purpose? Is it part of the wastegate duty command calculation?