928sg Posted October 17, 2019 Report Posted October 17, 2019 Is it possible to simulate an output that would show injector pulse width? I’m looking for a digital dash output so my cluster can calculate fuel mileage. The factory dash takes into account the fuel in the tank, as well as the injector duty cycle to calculate miles remaining and MPG. I’m running a link Thunder with sequential injection and COP for a 8 cylinder. The factory ecu and dash are coded for 19lb injectors but if I could get the signal and modulate it to take into account my ID 725’s and dial it in. Quote
Simon Posted October 17, 2019 Report Posted October 17, 2019 It might be as easy as sharing a Injector output. We do this on the GTR R34 to keep the center consul display happy. The catch with this is it wont scale for the bigger injectors. SO the next step would be to use a GP PWM and se the table up to span off injector duty. Quote
Adamw Posted October 18, 2019 Report Posted October 18, 2019 A couple of GP PWM examples below, the first one will send out a pulse that matches the injector pulse (roughly once every 2 revs, roughly same duty cycle as the injector). Since you have bigger injectors and want to tell the instrument that there is more fuel flowing than it appears from the duty cycle I think I would try adjusting the frequency table (so it sends the pulse more often - since you cant send more than 100% DC anyway). This first set up would give the same signal as effectively "teeing" into an actual injector wire: Since your new injectors have about 3.6X the flowrate of original, we could send the "pulses" 3.6X more often by doing this: It's hard to know if this will work as we dont know if the instrument already takes RPM into account from the tacho signal or it uses this same fuel used pulse. But worth a shot. Quote
928sg Posted October 18, 2019 Author Report Posted October 18, 2019 Adam, Thanks~! The PWM GP outputs look like they should do the trick. Quote
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