Using High Z Injectors...just want to confirm....

wwhalenc · wwhalenc's Garage

So from what I've read I can use almost any high Z injector (with the right flow rate/spray pattern/physical shape) by just wiring a resistor in parallel. I have a 951. Each injector is 2.4 ohms. Say I wanted to use a 10 ohm injector: 1/r1 + 1/r2 = 1/R ; 1/10 + 1/3.16 = 1/2.4 So I split the (+) lead going to each injector use my 10 ohm injector for one branch of that split and use a 3.16 ohm resistor and run the other branch to ground? Is this right? That's all it takes???

Techno Duck · Techno Duck's Garage

If i remember right the factory injectors are about 4.5-5ohms. They are weird.. sort of inbetween low and high impedance. Anyhow i dont think you can use 10ohm injectors.. you need to use a low impedance (around 2ohms) and can make up the difference using a ballast resistor.. you need 2, one each spliced to the wire coming off pin #14 and #15 of the DME harness. Technically with a low impedance injector you do not need to use a resistor (mostly street cars), however for a car that sees high injector duty cycle (track car or if you run full boost for long periods) the injector drivers in the DME get very hot and some have reported burning them out.

I am running Siemens Deka 72lb injectors on my car. They were about 2.4ohms impedance, i used a 2ohm resistor inline and have not had any problems with the DME getting hot on the track. I mounted them to a thin sheet of aluminum to act as a heat sink and used some thermal paste (for PC processors) inbetween the two...

wwhalenc · wwhalenc's Garage

Ok, i had it backwards...the NA are 2.4 or something. Wel it seems likel running lower Z than stock should be straightforward (since the resistance is just added for stuff in series). It seems like you should be able to run those high impedance injectors using resistance in parallel (most current is shunted through the resistor to ground while a fraction would be shunted to the injector). I'm no electrical guy (or even F.I. guy for that matter), but it seems it'd really open up the choices for injectors. --C