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How to Install a Zex Blackout Nitrous System on your 2011-2012 Mustang GT

Installation Time

4 hours

American Muscle
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#82390 & 82390B Ford Mustang GT Nitrous System

Thank you for choosing ZEXTM products; we are proud to be your manufacturer of choice. Please read this instruction sheet carefully before beginning installation, and also take a moment to review the included limited warranty information.

Nitrous Management Unit1
24" Hose, -3AN, purple2
3' Hose, -4AN, purple1
18' Hose, -4AN, purple1
Nitrous Nozzle1
1/8 NPT Bulkhead Fitting wi Nut1
Ford Fuel Line Adapter1
-4 AN to 118 NPT 90 deg. Fitting1
101b. Nitrous Bottle wNalve1
Bottle Bracket (short)1
Bottle Bracket (long)1
.024 N201 Fuel Jet1
.028 N201 Fuel Jet1
.032 N201 Fuel Jet1
.035 N201 Fuel Jet1
.040 N201 Fuel Jet1
.046 N201 Fuel Jet1
.054 N201 Fuel Jet1
.067 N201 Fuel Jet1
.083 N201 Fuel Jet1
Power Point Arming Switch1
Wire Harness w/Arming Switch1
Aircraft Switch Cover1
Red 18 GA. Wire10 ft.
White 18 GA Wire2 ft.
5/16- 18 Xl" Bolt for Bottle Brackets4
5/16 - 18 Nut for Bottle Brackets4
5116 Flat Washer4
#8 x 1/2, Sheet Metal Screw6
-4AN, 90 deg., Swivel Fitting1
118-27 NPT Tap1
TPS Resistor Wire1

All the power comes from the fuel, not the nitrous. Nitrous oxide is simply a tool that allows you to adjust how much and how quickly the engine bums the fuel. If the fuel isn't there, the power won't be either.

Avoid detonation at all times. Nitrous enhanced detonation is much more damaging than detonation that occurs when naturally-aspirated due to the increased amount of fuel available for releasing energy and the fact that more oxygen is present.

When system is activated, if something doesn't feel or sound right, BACK OFF. If you hear any detonation or feel anything unusual, get off the throttle. It's a lot easier to check everything over than it is to just try to drive through it and damage expensive parts. Don't activate or have the system activated when you hit the stock rev limiter. The stock rev limiter is a fuel cutoff. If you cut fuel while you're injecting nitrous, you're instantly very lean. This momentary lean condition has the potential of causing engine damage.

Spark plugs and nitrous performance: The factory spark plugs that come in the new Mustang GT are not suitable for use with any nitrous setting above 75 hp. Attempting to use the factory plugs at higher horsepower levels can produce a detonation condition after a few seconds of nitrous use. The solution to the problem is to install spark plugs that have a colder heat range and proper ground strap design for nitrous use. Consult your preferred spark plug manufacturer to ensure you install the correct spark plugs for the nitrous level you choose to run. Also, due to the cooler and denser inlet air charge that nitrous creates, it may be necessary to close-up your spark plug gaps to eliminate any misfiring.

In our experience, .030 to .035 in. spark plug gaps typically will ensure proper ignition. You may be able to run a wider gap, or you may have to close them up, just be aware of this if you start to experience an ignition misfire when you are using your nitrous system.

Engine modifications: The ZEXTM nitrous system, out of the box, is designed to work as a bolt-on kit for stock or mildly modified vehicles. Mildly modified vehicles would include header upgrades, exhaust upgrades, air filter kits, etc. If major engine modifications have been performed, a fuel pump upgrade will be required for safe nitrous system operation. Major engine modifications would include turbochargers, superchargers, aftermarket cylinder heads, head porting, camshafts, intake manifolds, etc. Failure to upgrade the fuel system when using nitrous in these highly modified applications may cause serious lean conditions that can result in severe engine damage.

Do not use Teflon sealing tape on any fittings in a ZEXTM nitrous system. It is easy for Teflon tape to get pulled into tne system, causin g blockages tnat can ultimately lead to incorrect nitrous system performance and potentially, engine damage. Only use liquid thread sealer for all NPT type fittings.

Do not use any thread sealing compound on AN style threads.

Do not attempt to start your engine if nitrous has been accidentally injected into the engine while it was not running. If this occurs, disable all eight of the ignition coils by unplugging the leads going to them. Push the accelerator pedal to wide open throttle and hold it there, push the clutch m, and wlth the throttle wide open, engage the starter and tum over the engine for several se􀁹onds to clear the nitrous from the engine. Failure to do this before attemptmg to restart the engme can lead to a dangerous intake system backfire.

Do not engage your nitrous system below 2500 rpm. This ensures that you will not have excessive cylinder pressures that could cause engine damage. When finished using your nitrous system, close the nitrous bottle valve and relieve the line pressure. This eliminates the possibility that nitrous could inadvertently accumulate in the intake manifold while the nitrous system is not being used.

Do not run excessive bottle pressures. Excessive bottle pressures, over 1 100 psi, are dangerous to your engine. Your ZEXTM nitrous system is calibrated and optimized to operate from 900- 1000 psi. Exceeding this will not improve performance. Over 1 100 psi also runs the danger of locking the nitrous solenoid closed due to excessive pressure working against the valve's plunger. If this happens, you must cool the nitrous bottle down to lower the pressure. This will allow the valve to operate properly again.

Start with the lowest horsepower setting and work your way up. This ensures if you have any tuning issues to work out on your vehicle, they will get sorted out with a smaller shot of nitrous that will be less likely to damage your engine. Once you have the car working well on the smaller shot, you can then safely start to step up your nitrous kit horsepower.

Make sure your vehicle has an adequate fuel supply. Nitrous systems put a large demand on your vehicle's fuel system. Make sure you have a large enough fuel pump to handle the demands of your engine, as well as the nitrous system.

How to adjust power levels: The ZEXTM Mustang GT Nitrous System is designed for multiple power levels. Metering jets installed in the nitrous nozzle control these power levels. To change the power output, all you need to do is install the appropriate set of jets. The correct combination of jets is listed on the tune-up sheet on the back of this instruction manual.

Engine computer modifications: Do not use any nitrous system if a non-nitrous custom tune has been programmed into your engine's computer. Custom computer tunes generally advance the ignition timing to optimize non-nitrous horsepower. If nitrous is injected while these non-nitrous tunes are loaded into your engine's computer, detonation will occur and this can lead to severe engine damage. It is important to only use computer tunes that have been specifically programmed for nitrous use.

Specific tunes for nitrous should have the ignition timing reduced, per the tune-up chart at the end of this instruction manual. It is generally recommended that you retard the ignition timing around 2 degrees for every 50 hp worth of nitrous used, based on an optimized ignition curve for your engine.

Installation Instructions

1. Decide where to put everything. Before you start to install the various components of this kit, you'll have to locate the best locations of each component by trial fitment and careful measurement. Remember, the stainless steel braided lines that connect the NMU to the nitrous nozzle are 24 inches long. Observe and mark the location on the air inlet tube where you would like to put the nitrous nozzle. The arming switch should be installed in a position convenient to the driver, but not in an area where it could be accidentally armed. Next, decide where and how you'll mount the nitrous supply bottle, check Fig. 1, 2, 3, and 5 for technical restrictions on bottle mounting locations and positions. In our experience, the passenger side of the trunk is an ideal location that has easy access under the vehicle for tightening the bottle bracket bolts. Finally, have a reputable perfonnance shop fill your nitrous bottle with automotive grade nitrous oxide before you begin. Do not overfill the nitrous bottle.

2. Mount nitrous supply bottle

A. Mount the nitrous supply bottle in the trunk of the vehicle, with the outlet facing down. You may want to consider installing in a safety blow-down tube (ZEXTM Part #82099), as most racetracks require one. Route the tube from the safety pressure relief cap to the exterior of the car, preferably under the car. Doing so will prevent your car from filling with a cloud of nitrous oxide should the safety pressure relief cap rupture.

B. Index the pickup tube with bottle position. (Refer to fig. 1, 2, and 3). ZEXTM nitrous bottles are designed with the bottom of the siphon tube at the bottom of the bottle towards the outlet. Always mount the bottle so that as your car accelerates, the liquid flows toward the pickup tube.

3. Mount nitrous delivery line under the car. When routing the nitrous delivery line under the car, try to use the sub-frame as a conduit (Fig.5). This protects the line and eliminates the need to use clamps. The supplied cable ties work if you can run the line higher in the under-body so that it's safe from road level obstacles such as speed bumps. For the pro-race look, you can use steel loom clamps with rubber sheathing to fasten the line to the body.

4. Mount nitrous management unit. Keeping in mind the length restrictions of the nitrous nozzle feed lines, mount the Nitrous Management Unit (Fig.4) in a suitable location. It's a pretty rugged piece of equipment that is built to withstand under hood temperatures as well as exposure to weather. Connect the nitrous delivery line to the nitrous management unit.

A. the Mustang's power point. There is an LED toggle switch made into the end of this plug that serves as the arming switch.

B. Whatever power source you decide to use, run the positive ( ) power wire through the vehicle's firewall and connect it to red wire that goes to the Nitrous Management Unit.

C. Take the black wire that comes from the Nitrous Management Unit and attach it to a suitable chassis ground. It is very important that the NMU is grounded to the chassis directly; do not ground the box through the power point arming switch. Grounding the NMU in the engine bay assures that the power and ground wires will get connected with the correct polarity. The electronics in the NMU will be damaged if the wires are connected improperly.

D. Locate the factory wire harness where it connects to the throttle body. Using the supplied red T -tap connector, tap into the "GREEN with VIOLET" striped wire. Attach the red crimp-on blade connector to one end of the white TPS Resistor Wire and plug it into the Ttap connector. Attach the other end of the TPS Resistor Wire to the white wire from the nitrous management unit. If the white wire from the NMU is not long enough to reach the TPS Resistor Wire, an extra length of white wire has been included in the kit.


Due to the sensitivity of Ford's throttle by wire system, the ZEXTM Nitrous Management Unit may cause intermittent check engine lights on some vehicles if the included TPS Resistor Wire is not used. It is required that you install the white TPS Resistor Wire between the engine's throttle position sensor (TPS) output wire and the white TPS wire going to the ZEXTM Nitrous Management Unit. Use of this resistor will effectively isolate the Nitrous Management Unit and prevent check engine lights from occurring. This resistor in no way affects the activation or performance of your ZEXTM nitrous system.

5. Program activation switch. Now that you have completed the wiring of your nitrous system, the next step is to program the activation switch. To program the activation switch, turn the vehicle's ignition on, but do not start the engine. Tum the nitrous arming switch to the "ON" position. Go to the nitrous management unit (NMU) and locate the push-button switch. Depress, then release, the push-button switch. Observe the NMU's operation light. At this point, it should be RED. This RED light informs you that the NMU's activation switch is in learn mode. Return to the driver's seat and depress the accelerator pedal to the floor, holding it there for ten seconds. Release the accelerator pedal and go back to the NMU and observe the operation light. At this point, the light should be flashing continuously from RED to GREEN to OFF. This is the NMU's way of telling you that it has successfully learned the voltage curve of your engine's throttle position sensor. Go back to the driver's compartment and tum off the system's arming switch, then tum it back on. Go back to the NMU and observe the operation light. It should be solid GREEN at this point. This informs you that the system is armed and ready to activate at wide-open throttle. Return to the driver's seat and depress and release the accelerator pedal several times. You should hear the solenoids click each time you reach wideopen throttle. At this point, your Activation Switch is fully programmed and ready for use. If you ever transfer your nitrous system to another vehicle, perform this same procedure on the new vehicle to "relearn" the NMU's Activation Switch.

6. Install fuel line adapter and fuel delivery line.

WARNING!! The factory fuel system maintains fuel system pressure, even when the vehicle has been shut off.

A. Locate the factory fuel line where it connects to the engine's fuel rail. Wrap a rag around the fuel line quick-connect, depress the release buttons and SLOWLY disconnect the fuel line, le:tting the fuel that is still under pressure escape and soak into the rag. This will depressurize the fuel system.

B. Take the Ford fuel line adapter and install the -4 AN 90 deg. fitting as well as the 1/8 NPT pipe plug into the outlet ports. Remember to use a liquid thread sealant on the fittings.

C. Push the fuel line adapter onto the fuel rail's inlet fitting, then slide the factory fuel line onto the adapter.

D. Attach the 3 ft. -4AN fuel line to the fuel fitting on the Ford fuel line adapter. Attach the other end of the fuel delivery hose to the nitrous management unit's fuel inlet fitting.

7. Check fuel and nitrous pressure lines.

A. Perform a final inspection of all plumbing and electrical connections to ensure that they are correct.

B. Ensure that the nitrous bottle is turned off and the line pressure is relieved.

C. Start the engine and observe all fuel connections for any leaks. Fix any fuel leaks before proceeding.

D. Turn off the engine.

E. Open the nitrous bottle valve. Listen carefully for any leaks as your valve is opened. Leaks in the nitrous supply line will be obvious because they will be covered in frost.

F. If everything checks out, close the nitrous bottle and relieve the line pressure.

8. Check fuel quality & ignition timing. The last thing to do before enjoying your new nitrous system is to ensure that premium fuel (92 RIM Octane or better) is in the fuel tank and that your ignition timing is programmed correctly. All recommended ignition timing retard amounts, in the Tune-Up Specs, are calculated off of the base, stock ignition table. It is not recommended to go above 75hp without an ECU reprogram, designed for nitrous. If the correct ignition timing program is not used for the higher horsepower settings, severe engine damage may occur from detonation.