Important -  Read the warnings at the end of this page.

What is Nitrous Control?

Nitrous Control is a feature of the s100 & s200 systems where the ECU control the use of Nitrous Oxide in the engine.  A dry Nitrous setup is be used (where the fuel is supplied by the ECU), with the ECU switching the Nitrous solenoid on via an output pin from the ECU.  Another pin input to the ECU is used to arm the system.

How does it work?

The ECU will ground an output pin to open a Nitrous control solenoid when a number of conditions are met:

• Nitrous system is armed.
• Engine speed is above a minimum setting.
• Throttle position is above a minimum setting.
• Vehicle speed is above a minimum setting.

At the same time the ECU switches the Nitrous on, it will supply an additional amount of fuel to the injectors, and optionally retard the ignition timing.  

RomEditor Settings - Arming Input

This selects the ECU input which is used to arm the Nitrous system.  The input needs to be switched to ground to arm the system.  Two input pins can be used, but note that the A/C switch will need to re-wired from stock in order to work.

RomEditor Settings - Output Control

This selects the ECU output used to control the Nitrous solenoid.  Use a relay between the ECU output pin and the Nitrous solenoid.  Note that the ECU will ground the output pin to switch the Nitrous on, so wire the relay accordingly.

RomEditor Settings - Conditions

These set the minimum conditions before the ECU will switch the Nitrous on.  As a rule only use Nitrous at almost full throttle and above 3000 rpm, depending on the size of the shot.  The minimum vehicle speed can be used to limit wheel spin in the lower gears.

RomEditor Settings - Fuel & Ignition

This sets the amount of extra fuel to inject and the amount of ignition retard when using Nitrous. For a starting point for the fuel enrichment value take the value from the fuel table at peak engine hp e.g.  if the engine makes 200 hp at 8000 rpm, and the fuel value at 8000 rpm and zero vacuum is 800, then you will need to enter a fuel enrichment value value of 100 for a 25 shot, 160 for a 40 shot etc.  This is only a starting point - dyno testing with a wide band lambda meter is the best way of determining the correct values.

Nitrous Switch Wiring Diagram

Warnings

Exercise caution when using nitrous.  Make sure that:

• The fuel injectors have enough capacity to meet the fuel demands when nitrous is used.
• To use a relay between the ECU and nitrous solenoid.
• The minimum engine rpm and throttle position are sufficient so that the engine does not backfire when the Nitrous is switched on.
• If you start laughing uncontrollably, immediately switch the system off, stop the car and go to the nearest rave.