Could someone with a better understanding please explain me how the ECU uses the specified rail pressure (KFPRSOLxxx)?
Lets say the stock map of an 200hp TFSI engine has 0,0333ms KRKATE, meaning the stock flow is around 1027cm³/min.
At this point I have to assume that the resulting cm³/min is at the stock fuel pressure which peaks at 110bar.
However since the stock KFPRSOLxxx maps specify a variable rail pressure based on different torque requests and rpms, how does the ECU handle the variations?
Does the ECU expect that the injector flow indicated by KRKATE is at the highest pressure value indicated by KFPRSOLxxx maps and then calculate the actual injector
flow based on that with following formula (e.g. specified rail pressure 90bar)?: KRKATE / SQRT(110/90)
So when the peak requested rail pressure is raised from 110 to 130bar the KRKATE must be correctly adjusted once again?
Let's say I would need 130bar fuel pressure instead of the original up to 110bar.
Should I leave the lower load and rpm lines in the KFPRSOLxx maps as stock and only raise the requested pressure where it is actually needed?
Also any preference should the changes to the normal operation fuel pressure be made to KFPRSOLHOM (normal operation) map directly or is it preferred to use the KFPRSOLOFF (offset) map?
Apologies, I feel like a leech