Posted on 23 Comments

FiTech EFI – Nitrous Instructions

  • N2O Solenoid Control
    • If the ECU is to be in control of the relay that drives the solenoids, set this accordingly.

    • If the ECU is used with a nitrous system, set this accordingly.

  • N2O Signal Level
    • If the signal that tells the ECU to enable nitrous is a +12V signal, or a grounding signal, set this value accordingly.

  • N2O Stage1 Retard
    • Spark advance should be retarded when nitrous is on. How much depends on the engine and nitrous combination.

  • N2O Stage1 AFR
    • A richer target should be set with nitrous. This is that target when the nitrous is on.

  • N2O Stage1 FUEL
    • Fuel can be added or subtracted when nitrous is turned on to help get the AFR closer to optimal. Often times, fuel needs to be removed because it displaces air intake through the throttle.

  • Gear Shift time
    • If the N2O MAX RPM is used to turn off nitrous, this time will delay the reenable of nitrous to allow time for the gear shift to complete.

  • RPM hysteresis
    • If the RPM fluctuates with nitrous on or off, it won’t flutter on and off unless the RPM varies by this much.

    • Above this RPM, nitrous will be turned on.

    • Above this RPM, nitrous will turn off.

  • N2O MAX Temp
    • Above this Coolant temperature, nitrous will be disabled.

  • N2O MIN Temp
    • Above this Coolant temperature, nitrous can be turned on.

    • Above this throttle position, nitrous can be turned on.

  • N2O re-arm TPS
    • If the Nitrous is disabled from being too lean, and throttle is closed beyond this, it will be re-enabled again – this is to prevent the nitrous from turning off and on repeatedly while the throttle is held open.

  • AFR check delay
    • After the Nitrous is turned on, a few moments of time are allowed to let the AFR settle, in case there is a quick lean bit at the beginning of Nitrous operation.

  • Lean disable AFR
    • If the AFR is leaner than this for the prior “Lean disable time” while Nitrous is on, the Nitrous will be disabled.

  • Lean disable time
    • If the AFR is lean for this much time while Nitrous is on, the Nitrous will be disabled to possibly protect the engine.

23 comments on “FiTech EFI – Nitrous Instructions

  1. my handheld controller has a signal input of high or low. And then it has a driver enable control and a nitrous enable option. I want the throttle body to run the nitrous off the throttle position switch and RPM.I’m not sure of what settings to run. I want the throttle body to ground my solenoid relay.I have tested everything wiring wise and confirmed my solenoids work when grounded so I feel this is a settings problem on the handheld.

    1. When using nitrous the EFI system needs to work through a relay ground. The high (12v) or low (ground) input if to enable the nitrous. Please give us a call with full details on setting up the nitrous.

  2. Hi Fitech, I Bought my 600HP PA kit a few months ago and i am planning on adding NOS in the future. I’m to curious to know if the fitech system controls how much fuel is added and sprays accordingly? Will I be running a “dry” shot but the fitech will compensate?

    1. The GO EFI Power Adder systems NEED to be used with a wet nitrous system. It will compensate some fuel but no where enough to run safely. Refer to your nitrous supplier for jetting of their kit to get you close for your engine and the EFI will do the fine tuning.

  3. Can I use the fitech meanstreet EFI system with a single stage of nitrous if I control the timing retard through my msd box and turn it on and off manually with a switch? I would need the meanstreet EFI to control and adjust the AFR when the nitrous was activated .

    1. There is a feature in the Mean Street to change the AFR target when the black wire is grounded.

      1. Do you consider the mean street EFI ” safe ” to use with a 150 shot nitrous plate? I would control my timing with my MSD box which would retard the timing by 6 degrees when above 3000 RPM when the nitrous was activated and I would leave my wide open throttle switch in place.

        1. Be sure to use the black wire on the Mean Street for AFR correction. When this wire is grounded or supplied 12 volt (configurable in handheld) the system will target an air/fuel ratio of your request. The AFR should be set to what you want your nitrous to run at.

  4. Can I add Nitrous to the non PA 600 later down the road?

    1. Adding nitrous to a non power adder system will not work.

  5. if i am taking a previously fuel injected car, putting a carbed intake on it, and running one of your power adder TBI kits could i still use my EFi fogger plate on my intake tube if mounted the proper distance from the throttle body like it was? or would i have to use a carb plate set up? Also could the computer built into the system replace my MSD window switch for controling the nitrious?

    1. The power adder kits have full nitrous control which would eliminate your MSD window switch. As long as you are injecting fuel with the nitrous you will be able to use the fogger.

  6. Hi,

    I am very interested in running the 1200 HP power adder version . I cannot find a lot of “real world” information about running FITech with a direct port (i.e. fogger) system.
    I am sending my intake to Induction Solutions to get a single stage system installed. I will be looking at tunes from 250 to 400 HP. The motor is a 489 BBC. It dyno’ed at 575/570. With the new mods, I am hoping to squeeze another 50-75HP out of her. It will be below the 1200 HP mark. My nitrous set up has a dedicated fuel system. I spoke with IS and they said it should work as related to getting activated and such, but they have no experience with FITech.

    The car is a street car that will make passes at the track. Before making the investment in both of these items, I want to make sure they will work well together. Any information you can provide is greatly appreciated. I know others are out there interested in the same thing.

    Thank you.

    1. The Go EFI 8 will work with direct port nitrous as long as you are injecting fuel with it.

      1. Thanks Bryce!

  7. Hello, I just purchased the Go efi power adder 8, I’m running a big shot plate system with a transbrake ,so when brake button is engaged nitrous wont come on until I release the button with the throttle wide open. With this setup I run 2 relays, my transbrake relay activates the nitrous relay. When the activation switch is turned on it goes to the w.o.t. switch then to the transbrake relay. I want to use the power adder to control my nitrous so instead of the w.o.t. switch can I set this up with the programmer? Also with that being said should I use the nitrous out wire to ground the transbrake relay or both nitrous and transbrake relays? I been looking for wiring diagrams with your system used with nitrous and can.t find any or am I overlooking it?

    1. When it comes to the EFI system is has an ARM wire and an activation (through a relay) wire. If you put the arm wire so that it receives 12 volts when the trans brake is let go and you turn all the activation setting down in the handheld the system will turn on the nitrous right away.

  8. Is there any way to use the nitrous application to trigger the kickdown on a turbo 400 trans? In other words, could a wire be programmed to switch on at WOT to activate a relay? Otherwise, are there any plans to make a kickdown switch and bracket for the throttle body?


    1. From the way you describe this it sounds possible. There is only one way to find out and this is to try it. I would appreciate feedback on if you are able to do this.

      1. I have it wired up and adjusted the settings. I will keep you posted as to how it works when the weather clears up and I can drive the car.

      2. Bryce,
        It works! I have the nitrous control wire triggering a relay which controls the kick down. I can adjust the kick down simply by adjusting the throttle percentage to activate the nitrous. Also, the rpm signal code kept coming back, so i wrapped the EFI harness in metal braided shielding and it completely solved it. My harness was close to both the plug wires and the alternator.

  9. I have the power adder 600 EFI with fitech inline fuel system. how do I get fuel to the nos ? My 125 power shot ask for 6 psi

    1. With the inline kit there is no way to drop fuel pressure to 6 psi. Your best bet is to jet the plate to work at the 58 psi. Your other option is to run a separate low pressure nitrous fuel system.

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