Apologies first off if this is the wrong forum for this (can't find anything really applicable).
I'm working with a GM/Delphi ECU from a Harley v-rod (rumor has it it's from a marine ECU that Delphi slightly modified for HD).
At any rate, my concern is around barometric pressure reading.
The ECU has a single pressure sensor, the MAP sensor. Couple that with the fact that the ECU is really a hybrid of alpha-n for VE and speed density for AFR and spark.
Now....I believe the ECU reads the output voltage of the map sensor with key on engine off to take a base reading of the ambient air pressure.
That much I can handle (did I mention I'm installing a 2 bar sensor in place of the 1 bar? Yes I know I need to scale the voltage at KEO such that the 2 bar sensor will show approximately 4.75-ish voltage to match what the 1 bar would in this condition).
What I want (read: NEED) to know is if the ECU is reading baro (recall with ONLY one map sensor for pressure readings) at any other condition. I have been told the following (of which I have no idea who knows the truth...):
It reads only at key on engine off.
It read at idle (which I believe would be 1/3 the voltage of what really ambient is...)
It reads "all the time".
It takes a reading when you got WOT.
Dilemma: First, anyone that can share some insight into this I appreciate it. Second, IF it's reading at WOT (or really any other time besides key on engine off) I am at a loss for how I can make this work....supercharging the bike that is. FYI: The ECU only has a 100 KPa OS such that I indeed plan on scaling the tables such that 60 KPa and up will equal boost for AFR/timing/etc values.
For the MAP sensor offset at key on engine off I was planning on using a Split Second map voltage modifier to add (or subtract if needed) an offset. What I can't account for is the engine on scenarios (IF they exist). Unfortunately I don't have/know a PID that states "Baro pressure" for this ECU (only MAP value and voltage)....
Thoughts?