Fuel controller

[DKz Garage]

Looking for some input on running a fuel controller on my LT4 swap. Putting a crate LT4 in my 69 Camaro, running a Rick's tank with a GM ZL1 in tank fuel pump/regulator. I've talked to a couple of the harness vendors...they are saying most guys do not run them?? The cost to add the fuel module to the harness is not much...so it's not a cost thing. Any input would be appreciated...

[dhutton]

I run a Vaporworx PWM controller in all of my builds.

Don

[DKz Garage]

I run a Vaporworx PWM controller in all of my builds.

Don


Thanks Don, I bought a Vaporworx PWM for my LSA Camaro build (in progress). For my LT4 swap... All the wire harness vendors are saying "you really don't need it, we very seldom include them in our harness". My understanding is this..... with a supercharged motor, the fuel pump (ZL1 pump) will put out a constant 70 psi, regardless of fuel demand. The PWM, will dial the pressure down when the 70 PSI is not needed, hence reducing the load on the the fuel pump, extending life, cooler pump temps, etc....

[dhutton]

That is not quite correct. A PWM controller regulates pressure by varying the duty cycle of the pump voltage. In most applications the pressure is constant, 58-60 psi for most NA LS applications. The GMPP LSA ECM is a little different where the pressure is boost referenced if I understand it correctly. Boost referenced means the fuel pressure varies with boost level as specified by GMPP.

In my LSA the Speartech ECM does not require boost referenced fuel pressure, it uses a fixed 60 psi and that is what my Vaporworx controller is set for.

Hopefully Carl will step in and correct me as needed.

Don

[icemanrd19]

In my gmpp boosted ls3 I’m using the vaporworks controller and map reference. At idle fuel pressure is 42psi and ramps up based on fuel Demand. Doesn’t heat up the fuel, less wear on the pumps and extends life

[CarlC]

The LT series of GM crate engines typically uses a 70psi constant fueling strategy regardless of type. However, GM's fuel volume requirement is, IMO, incorrect for LT4/5. They note the same fuel volume for LT1, LT4, and LT5.

If Rick's has supplied the ZL1 fuel module that has been converted using a 60psi regulator and adapter, then that's not meeting GM's 70psi need. If PWM is used the OEM regulator should be re-installed.

There are two options for properly controlling the modern returnless fuel module using PWM: The GM FPPM (Fuel Pump Pressure Module as noted in their crate engine controller installation instructions) or the VaporWorx controller.

Either will work fine for a single ZL1 or CTS-V. The GM FPPM is limited in its power output, so if you ever want to run two ZL1 modules or a voltage booster, then VaporWorx has you covered with multiple options:
1) Use the VaporWorx DualX controller to run both modules (no GM FPPM needed). This controller can be run in single pump mode as well, making it ready for future upgrades.
2) Use the GM FPPM and add a VaporWorx Ally controller to handle the needs of the second pump. The GM FPPM will not handle the power needs of two modules, so the Ally acts as a piggyback controller. By taking commands from the FPPM pump + output, the Ally drives the second pump, hence full closed loop control of both pumps without MIL codes.
3) VaporWorx has a stand-along controller that will control the ZL1 fuel module. No ECM interface needed except the turn-on signal.
4) All VaporWorx controllers are rated for 22v operation. Most GM FPPM's get pretty unhappy above 16v.