Can i use a low/high-imp injector combination?

[RotaryProphet]

The problem is, even with resistors on the low impedance injectors, you'll have two high impedance injectors that open at the correct rate (about 1ms before the start of fuel flow @ 13v), and two high impedance injectors (thanks to the resistor) that open more slowly (about 1.4-1.8ms @ 13v, depending on the brand.) If both injectors acted like that, you could tune around it by increasing the injector open time in the ECU, but you'll probably have some trouble tuning the transition from your primary to secondary injectors; bringing them in earlier to compensate for the fact that a 1.5ms pulsewidth is giving you basically no fuel.

It's definitely doable in a mainly street driven car, but it wouldn't surprise me to see some hesitation in there at the boost threshold.

[RETed]

Originally Posted by RotaryProphet

The problem is, even with resistors on the low impedance injectors, you'll have two high impedance injectors that open at the correct rate (about 1ms before the start of fuel flow @ 13v), and two high impedance injectors (thanks to the resistor) that open more slowly (about 1.4-1.8ms @ 13v, depending on the brand.) If both injectors acted like that, you could tune around it by increasing the injector open time in the ECU, but you'll probably have some trouble tuning the transition from your primary to secondary injectors; bringing them in earlier to compensate for the fact that a 1.5ms pulsewidth is giving you basically no fuel.

This point is moot.
The stock fuel delivery with the stock ECU always runs on the rich side.
Running slightly lean due to the increased dead time of the fuel injectors is not going to noticably change the way the engine is running.


-Ted