The initial configuration is going to be using Microsquirt control fuel and re-use / re-purpose as many factory sensors as possible in order to make it as near plug-and-play as possible.
Integrating ignition will occur after I have established good fuel maps.
The bike is an 80 degree, odd-fire v-twin with factory turbocharging (18PSI+ boost) and factory EFI. It has 2 crank VR's (left and right, used by a separate ignition computer) and the EFI uses 2 cam VR's (left and right), two fuel injectors, a TPS, a coolant temp sensor, an intake air temp sensor (mounted just after the air filter) and 3 MAP sensors controlling the factory injection ECU. It also has two relays for the fuel pump and such but I will work those out separately from this.
It has been established that I will be using the 2 cam VR's during the fuel-only configuration as they appear to have acceptable outputs. As such, the 'squirt will be configured as if running in dual-spark mode: this is to accomodate the future transition to using the crank VR's and taking over ignition.
The cam VR's signals look like this:
It is also established that I will be using two of the three MAP sensors for input to the 'squirt: its P1 sensor which sources its signal just after the air filter and thus will be suitable for barometric sensing; the P2 sensor which has the range at 5v to sense boost to over 2.5 bar above barometric.
A visual representation of each sensor's range is shown below and as you can see, no single sensor is conducive to all-around operation.
The P1 sensor is connected to the intake after the air filter, as mentioned. P2 is connected to the "surge tank" between the turbo and the throttle, and Pb is connected between the throttle and cylinders. As the P2 sensor lacks resolution below -0.5bar, I'm contemplating connecting P2 to Pb's port and then using alpha-N (at low rpm) then transitioning to speed/density at higher rpm's, with the transition to speed/density occuring at approximately 4000 rpms, which is where the turbo is making significant boost (>5psi). I've not ruled out using a 3-4BAR sensor to replace Pb (or P2 even) should it be more beneficial.
My question is with regards to the best way to do this, sensor selection, tuning and all.
The bike will be outfitted with wideband O2 during the entire tuning phase, if not permanently.
Should I disable the turbo and "autotune" to stoich to generate an appropriate table for alpha-N, then enable the turbo and tune to AFR under boost, obviously starting rich (10:1) and leaning it out in steps so as to not damage the engine?
I'm just looking for the most efficient way of doing this, and am willing to listen to any suggestions.