WGDC Calculation

impuls

Specialist
Jan 28, 2018
91
59
0
Ride
'07 335i
I am currently trying to self tune my 335i and struggling to understand how final WGDC % is calculated exactly.

Guess I can continue to dial in spool without understanding that details, just curious...

wgdc base value % is pretty clear after reading what @jyamona wrote long ago another forum.

WGDC Base table val is looked up and loaded into memory. Adder Airflow is looked up, added to base. This val passed in as the X-axis lookup along w/ MAF as the Y to WGDC to WGDC Position table. This table lookup result is stored in mem. It is then passed into the WGDC Pos back to WGDC table as axis lookup. This lookup result is stored in mem. It is then added to the initial WGDC base value, to give your new WGDC Base. PID is now applied.

wgdc after PID is quite clear, but why is it adding to the base although boost is over target in this log https://datazap.me/u/impuls/v113-0?log=0&data=0-3-7-22-29-30-31&solo=0&zoom=29-43&mark=34&hg=5-4?

Could that be caused by the I factor?
Looking at the stock I factor table it is adding WGDC if the error is zero... WTF is the point of that?

Any hint how wgdc bank x % is calculated from wgdc after PID would be really appreciated.
Why is it constantly 10 - 15 % higher than wgdc after PID?
 

titium

Private
Nov 8, 2016
48
9
0
Australia
I am currently trying to self tune my 335i and struggling to understand how final WGDC % is calculated exactly.

Could that be caused by the I factor?
Looking at the stock I factor table it is adding WGDC if the error is zero... WTF is the point of that?

Guessing the error of 0 will cause the I factor term to be zero (i.e. do nothing). However by having a value in the 0 error column you can extrapolate for small errors either side of 0, without actually having to define them.

As for your why the PID is adding WGDC have you looked at whether you're hitting load target?
 

impuls

Specialist
Jan 28, 2018
91
59
0
Ride
'07 335i
Guessing the error of 0 will cause the I factor term to be zero (i.e. do nothing). However by having a value in the 0 error column you can extrapolate for small errors either side of 0, without actually having to define them.

Thanks, now the positive numbers in the 0 column do make sense.

As for your why the PID is adding WGDC have you looked at whether you're hitting load target?

No, but does it really matter?
Boost is above target and the DME is even slightly closing throttle to compensate.

First log link was quite useless, this one does really show the relevant data: https://datazap.me/u/impuls/v113-0?log=0&data=3-7&solo=0&zoom=31-41&hg=31-29-18-19-25
 

impuls

Specialist
Jan 28, 2018
91
59
0
Ride
'07 335i
Anybody has an idea and is feeling generous enough to share what is added to wgdc after PID to calculate wgdc bank x?
 

V8bait

Sergeant
Nov 2, 2016
493
753
0
Texas
WGDC base % logs wgdc base table in logs mostly. There's a few other tables that obv adjust this and move it like the coolant temp compensation and other temp tables I think. Not overly important to mess with those.

WGDC after PID logging, when compared to base, is how much PID is doing. Boost error, p factor, d factor all determine this as well as time and whatever else. Don't get caught up on specifics if you're over it'll eventually remove, but not immediately if it was just adding a lot of positive duty cycle.

WGDC bank X % logging = WGDC base + PID + all airflow adder tables.
 
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