Need help wiring extra injectors

[chaclark83]

Can anything be damaged from using extra injectors with the stock edu. Can it damage drivers or anything

 

[silvreclips]

If you hook up more than 4 injectors to the stock ECU it may damage it.

 

[steve]

The injectors drivers can only handle so much current. That's why we have a injector resistor for each injector on the turbo cars.

What are you going to use to reprogram the ECU for the larger effective injector?
Why not just run one set of larger injectors?

 

[chaclark83]

This is an experimental car. We want to be able to run many different combinations of injectors. 240 390 450 Ect. It's on a 95 non EPROM ecu with an afc. The part I don't understand is how 2 injectors at low DC use more current than one at high DC

 

[steve]

It's on a 95 non EPROM ecu with an afc. The part I don't understand is how 2 injectors at low DC use more current than one at high DC

The current is limited by the injector and the injector resistor. The power used changes with Duty Cycle but the current that flows is subject to ohms law. Try running the numbers for parallel resistances.

 

[silvreclips]

If you take out the resistor pack you may be able to wire in another injector and use a smaller resister on the power wire but you would have to know what your doing to keep from frying an injector the ECU.

 

[VelocitàPaola]

If you take out the resistor pack you may be able to wire in another injector and use a smaller resister on the power wire but you would have to know what your doing to keep from frying an injector the ECU.

It's really not a good idea to connect two injectors in series.

The best approach would be to make a driver circuit out of a bank of eight TIP122 darlington pair NPN transistors. Have these transistors' bases connected to the ECU's injector outputs, through the appropriate base resistors and possibly an octal inverter with pull-up resistors. You'll need a second resistor pack for the new set of injectors too.

 

[twdorris]

It's really not a good idea to connect two injectors in series.

I certainly agree with that statement. However, it has been done before if you really wanted to do it. You'll need some massive deadtime compensation, though. Russ Coxe ran a dual bank of 1600cc injectors (2 in series per cylinder) with his 95 ECU back in the day. He was running pure alcohol, though. And he couldn't have cared less about idle quality or anything else other than wide open throttle performance.

It's just not a good setup, though. Too hard to control it properly, IMO.

Thomas Dorris