MSefi.com read only forum (Jan.15,2018)

So I'm getting ready to run a high compression low boost set up on E85. I was running 23lb high impedance. I just got some 55Lb low impedance (3ohm). I will be running a single flyback board circuit.

I read through the "injectors and fuel supply".

I'm not sure what the amp requirement for the 4 injectors are to calculate a ballpark (edit: pulse width percent for the pwm setting not fuel pulse width)

on the surface, 12ohm to 3 ohm is 25% so somewhere around 25%+ pwm setting. is it that simple?

Usually for the PWM current limiting, you'll start with 30% current limiting and adjust from there.

The pulse width is separate from current limiting. You should get in the ballpark by just scaling Required Fuel as appropriate and adjusting the cranking pulse widths to match.

I'm famillier with req fuel and tuning idle pulse width with the HighZ injectors.
So start @ 30% pwm, is that because the required current draw is close to the same for high and low imedance injectors?

No, it's because this is usually a setting that isn't likely to fry anything when you first crank up the engine, even though it may not be ideal.