So I've been looking at a fuel management set up that is supposedly a parallel system instead of a piggyback system. I'm just curious if anyone has tried to run a parallel system before.

The difference from everything I've read so far is that the parallel system basically has it's own ecu and thus can in theory replace some of the stock ecus functions instead of taking the stock ecus outputs and trying to change them which from my understanding is what a piggyback set up does.

The parallel system would share inputs with your stock ecu but would completely replace the outputs.

Some shared inputs are Temperature sensors, Throttle position sensors, Crankshaft position / camshaft position sensors, and O2 sensors.

An example of a replaced output would be your injectors. meaning I'd cut the lines from my stock ecu -> injectors and instead let the injectors run of my new set up, plus the vac line.

If I am able to get this set up running on our cars it would be the equivalent of a standalone fuel management system, but wouldn't have all the little nifty tricks some of them have.

something I'm still researching, but I thought I'd post it on here and see what some of the old timers think.