Im wiring up my wolf3d v4 and I dont think the BAC is worthy of running 2 wires all the way to the other side of the engine bay. All the injectors and BAC need 12V power when ignition on, so I dont see why not just continue the wire chain over to the BAC. Will 14 gauge wire and a 30 amp relay handle the 5 things sucking power from it?

 

I don't know the amperage on injectors, but I'd say it would be fine. Only thing I would be concerned about is how fuel injectors have preference on their own stable voltage. If the BAC turning on drops line voltage to the fuel injectors, the injectors will drop pulse width (, or inject timing) and you might lean out.

Spend the extra $4.00 and do it right (and possibly save your engine?).

 

The BAC pulls a medium amperage current, but it is often pulsing during idle.
The shared 12v feed may see some harmonics with the injectors, which could sometimes upset the idle.
No effect at all while driving.
No biggie - just a consideration.

 

I notice the stock system uses the 40a fuse to feed the fuel injectors and the ignition. It uses the 30a fuse to feed the solenoids. Just FYI.

 

BAC is pulsing? Any idea on the amperage? 5amps or so?

 

A fully warmed up series five car with no A/C on etc......the bac draws approx 137 ma.

A cold/cool engine will give you about 290 ma on start up and slowly drop down to the 137 ma once warmed up.

A fully warm car with the A/C on full blast, results in a draw of 269 ma.

A fully warmed up engine with just the headlights on gives us a draw of 265 ma (where's that dodo head that told me the bac on a series four did not compensate for headlights???).

So that's about all the thing will pull. Stone cold should result in perhaps a higher figure along with the draw upon starting (opens to full open during starting).

 

So I should probably give it its own relay.

 

It does not pull much amperage, but I'd keep it off the circuit that has the fuel injectors etc as a safety move. Sort of like if the bac or its wiring goes bad and pops a fuse, then only the bac is disabled but the fuel injection is still working and the car is still going down the street. But if both are on the same circuit then the car stops stone cold dead. I could be over reacting.