Injectors - Pulse Width to Volumetric Efficiency

[AdamQ]

I'm in the process of putting together a base map for a 2.0 Ford Duratec. I have suitable maps from other ECUs that contain PW figures for fuelling.

I obviously need to convert PW to VE (as a starting point at least) and that is my question - how?

The manual gives (for Alpha-N fuelling):

PW = INJ_CONST * VE(tps,rpm) * AirDensity * Corrections + AccEnrich + InjOpeningTime

where INJ_CONST is "a constant for the given size of injectors, engine’s displacement, pressure 100kPa, temperatures of the intake air 21°C, VE 100%, time of injectors’ opening required to obtain the stoichiometric mixture (Lambda = 1)"

It seems I need a value for INJ_CONST. I've searched here and have Googled, but am struggling to find anything definitive. My injectors are Bosch 0280 156 095 items which are 315 cc/min.

Any assistance would be much appreciated.

Adam

[WHPZach]

It will take you far less time to build a proper VE table than to do the math to reverse engineer a PW table. Enter 50% in all cells, which will get the car running, then tune from there.