How Nitrous Injection works

Nitrous Oxide has far greater Oxygen content than the air we breathe (36% vs 21%). At temperatures above 570F (300C) Nitrous Oxide splits into oxygen and nitrogen, immediately providing more oxygen to the engine.

To supplement the extra oxygen, more fuel is added to the mix creating a much more potent air/fuel mixture, resulting in a power increase.

Nitrous Injection also cools the intake air. While this may be dismissed as a minor side effect it does, in fact, provide a significantly better environment for combustion allowing more fuel to be burned and thus creating more power.

Fitting Nitrous Injection

There are many types and methods of fitting Nitrous Injection. Generally the injectors (Foggers) are installed into the induction system or directly into the engine itself.

The simplest method (as used on the Mighty Car Mods’ Honda S2000 in our video) is a switch-activated setup consisting of a single fogger in the intake, a solenoid and an activation switch.

This system does have some limitations and shortcomings but more on that later.

Benefits of Nitrous Injection

Nitrous Injection is relatively inexpensive, easy to install and provides a significant increase in power output. A simple, single fogger setup in the MCM S2000 yielded a 40kW increase from an almost stock, factory motor.

Drawbacks of Nitrous Injection

It’s a system that’s only available on-demand. You don’t have all that extra power at all times, it only comes one when you press the activation button and lasts until your Nitrous Oxide supply runs out.

Being a gas, Nitrous Oxide requires a lot of room, even in liquid form. You will need to sacrifice fair bit of boot space to fit a NOS bottle. A 10 lbs bottle will only give you a 2-3 minutes of NOS supply.

A switch-activated nitrous setup can be dangerous. You have to cautious when you activate the injection. If Nitrous Oxide is injected at too low of an rpm, the gas will accumulate in the intake and eventually explode. This can cause serious damage to your engine components.

How ECU-controlled Nitrous Injection works

In this setup an ECU is used to activate the Nitrous Injection creating a much safer, more reliable and fully programmable system.

To show how this system works we have used Mighty Car Mods’ API F20C Honda S2000. The car already had a simple, button-activated NOS system fitted to it so all we had to do is convert it to an ECU-controller setup.

Installing a Haltech Platinum Pro Plugin ECU is a straight forward process. Being a make and model specific unit, the ECU plugs straight into the factory harness.

Once a base map is loaded we then set all requirements for NOS activation. These will include RPM, throttle amount and coolant temperature.

The ECU will now ensure all the pre-set parameters are met before activating NOS injection. The activation switch will now be used to arm the system but the final decision when to provide NOS injection will be made by the ECU.

A quick tune and we can see that the ECU-controlled system still provides a significant power increase albeit in a much more controlled, reliable and, most importantly, safer way.

Benefits of an ECU-controlled Nitrous Injection

• NOS will only be activated when the engine can accept it – ie within the right RPM range, over the right throttle amount (70% or more), within the right coolant temperature.
  
• Setting the parameters for NOS activation prevents a potentially dangerous Nitrous Oxide accumulation in the intake.
  
• ECU provides infinite tuning options allowing you to adjust fuel, timing and retarding ignition, all of which can in turn yield more performance gains.
  
• With our S2000 Pro Plugin ECU we can also adjust the VTEC activation point to work in conjunction with Nitrous Injection.