badhombre

iTrader: (4)

so I had an idea about how to possibly run a set of piggyback injectors using the stock PCM and such, and not sure if it will work or not. say for each injector, you tapped the switched ground signal from the original injector up to the secondary, but then tied the positive feed wire of all of the secondary injectors on something like a window switch or boost switch. this way they will only get power at pre-determined boost or rpm levels, and the pulses will be in time with the injector they are piggybacked off of. I'm sure some creative tuning may be involved in being able to compensate for the sudden increase in fuel supply. but it's just a thought, wanted to put out there and see if anyone had any ideas on it. or if it is already being done

Reckless

iTrader: (9)

Might get better results in the tuning section >>>>>>>>>>>

badhombre

iTrader: (4)

not sure how when it was directly a fuel system question? but we can try it

LSxPwrDZ

iTrader: (4)

Wont work. The factory injectors are wired that way already. The PCM provides a ground for the injectors and completes the circuit. Wiring a second set would overload the drivers in the PCM. The only way to make that work is to piggy back the signal off the stock injector circuit to an injector driver like the AEM that has it's own control circuit. Doing that though would be just as easy to buy a bigger set of high Z injectors.

jack27

u can make another 8 injectors working

check with Lingenfelter
they have their Zo6
i saw it in my eyes 16 injectors
and after some fixing in the car ,, i will tune it in the dyno

minytrker

iTrader: (13)

I almost 100% sure they are not running the second 8 injectors on the stock pcm.

LSxPwrDZ

iTrader: (4)

What ECM/PCM? I'm kinda interested in this now cause two sets of 60s or 80s are cheaper than 120s or 160s haha.

badhombre

iTrader: (4)

well to my understanding it just pulses a ground signal and there is no real load there. the power would be provided by the external source. idea was inspired by my friend suggesting me to piggyback a set of factory 36lb injectors from the supercharged 3800 on with my stock injectors on my 5.3 for being able to support boost

Mike454SS

iTrader: (4)

IT pulses the ground, which means all the injector current goes through the driver in the PCM...doubling the injectors wired in parallel would cut the resistance of the circuit in half/double the current through the PCM, and blow out the drivers in the PCM. You'd also have some really screwed up calibration data for more than just the flow rate.

black06g85

iTrader: (6)

I'm working on something with the cobalts, but will be looking into it for my trans am also.
I know hahn racecraft had something out for a while to control a 2nd set of injectors (non sponsor so no link). it was called the port fueler if you want to look into that, pretty sure it ran off a map signal and had its own tuneable injector map

TurboS10

iTrader: (12)

DIY Autotune has or had, haven't looked lately, a driver box for the MegaSquirt to run different injectors. Not a resistor box.
It was only a jumper to make it run high or low Z.
Piggy back that box onto the stock setup and drive as many injectors and boxes as needed. The box only uses the PWM signal and has it's own power cable since the injectors are wired to the box.
All the injectors will have the same PW signal. The transition to the extra injectors is the hard part of tuning.
Use a switch of your choosing to control the signal to the driver box. The LT5 used this scheme from the factory IIRC. If you dig up the wiring diagram you'll see the relay. It had a 4v head so gm used a relay to control an air valve and the respective injector to turn half the induction sys off for low power driving. hmm... I'll have to dig up the ECM program hac for that car and see what they did for the fuel.


You can run high z injectors on low z drivers ok, but not the other way around.
Adding a second set of injectors to a high z driver will over heat the driver and burn it out.