This section covers features used for controlling nitrous oxide systems and for controlling ignition and fueling requirements while a nitrous oxide system is in use.

NITROUS FUEL TABLE

Displays a 2D table of injector flow in pounds per hour vs. RPM used for fueling the engine while a nitrous oxide system is activated.  There are 3 curves shown on this graph, each of which represents a fuel curve for the corresponding nitrous stage.  Pressing the [Tab] key will switch the edit cursor between these stages.

Fuel flow, as it is displayed in this table, is entirely dependent on the injector flow rate setting in C-Com WP.  As long as the desired volume of fuel is entered and the injector flow rate setting is correct, the required injector pulsewidth for that volume of fuel will be determined automatically.  If you aren't sure of the actual flow rate of the injectors in use, it is recommended to have them flow-tested.  Flow-testing is a sure-fire way to know exactly what you have, and it's cheap insurance against inadvertently adding the wrong amount of fuel when using nitrous oxide.  Nitrous doesn't leave a lot of room for guessing, so be sure you know exactly what you have. 

When running a dry-flow nitrous oxide system (meaning that the required additional fuel is provided through the injectors rather than a separate fuel system as conventional nitrous setups do), the manner in which additional fuel is applied from this table is different between speed/density mode and Alpha-N mode.  In speed/density mode, when the nitrous oxide system is activated, the values from the above fuel table will be applied in addition to the fueling applied from the base fuel table.  In Alpha-N mode, when the nitrous oxide system is activated, only the values in the above table are used - the base fuel table is not used.

If Alpha-N mode is being used, an excellent way of creating a "base" fuel curve is to use C-Com WP's data logging feature to record a run without the nitrous system being activated.  By monitoring a sensor called "Fuel (lb/hr)" you can record how much fuel is being used at any given RPM and build a base fuel curve in the nitrous oxide fuel table from that information.

Nitrous oxide is an effective and relatively inexpensive way to build lots of additional horsepower - but it can be a dangerous experiment in the hands of an inexperienced engine tuner!  If you are the slightest bit unsure about what amount of additional fuel is appropriate for the amount of nitrous oxide you wish to inject in your engine, consult a professional engine tuner before proceeding!  Nitrous oxide tuning is a subject that is not well-suited to being included in this manual, as there are many combination-specific details that play a part in determining what is safe and what isn't.  

NITROUS ACTIVATION PARAMETERS

Items in this menu are used to specify under what conditions a nitrous oxide system will be enabled by the ECU and to control special fuel and ignition timing features used with nitrous oxide systems.  Click on any of the parameters in the image below to jump directly to information on that topic.

Number of Stages
Selects the number of nitrous stages to be used.  Most Bank-to-Bank systems offer one stage of nitrous control.  Two-stage and four-stage control is an option on sequential systems.

TPS Enable Threshold
This parameter sets the minimum throttle position  (%TPS) required before the nitrous oxide system is enabled.

Minimum RPM for Activation
This parameter sets the RPM level that must be exceeded before the nitrous oxide system is enabled.

First through Fourth Stage Delay
When the “Number of Stages” parameter is set to 2, 3, or 4, these parameters set the delay time for that stage from the moment the nitrous is first activated.  As an example, if the second stage delay is set to 2 seconds and the third stage is set to 3 seconds, The second stage will activate 2 seconds after the first stage, and the third stage will activate 1 second after the second stage.  When the “Number of Stages” parameter is set to one, the second stage delay setting will apply to the first stage.

The fourth "stage" of control allows you to specify a positive or negative percentage of fuel enrichment downtrack to compensate for variations in bottle pressure.  There is also a provision for a fourth stage of ignition retard.  A control output for a fourth nitrous solenoid is not available. 

First through Fourth Stage Ignition Retard
This parameter indicates the number of degrees of timing to be subtracted from the base timing while that particular stage is active.  These values are not additive values.  As an example, if you have a 10 degree retard specified for the first stage and want to remove an additional 6 degrees when the second stage activates, the second stage ignition retard value should be set to 16, not 6.

Dry Flow Enable
When this radio button is selected, the additional fuel required when the nitrous oxide system is activated will be provided through the fuel injectors by the ECU.  The ECU will use the injector flow information programmed into the nitrous oxide fuel table described above.  This requires that the injector flow rate is correctly entered in the Global Setup Parameters screen!

It is critical to verify that your system uses a fuel pump and injectors capable of flowing the amount of fuel necessary for proper operation with nitrous oxide in your application.  Even if your fuel table is properly programmed, reaching the physical limits of your fuel system while using nitrous oxide may result in injury and/or severe engine damage!

Wet Flow Enable
When this radio button is selected, the ECU will activate the nitrous oxide system but will continue to use the base fuel table for fuel delivery.  The nitrous fuel table will NOT be used.  The additional fuel required for nitrous oxide operation must be provided externally, such as through a fuel solenoid typically used in nitrous oxide systems.  The solenoid control and spark retard functions will operate as programmed.

N₂O CL A/F Ratio
If closed loop operation is selected, the Target Air/Fuel Ratio will be commanded to this value when the nitrous oxide system is activated.