Fitting N2O systems (NOS) to cars and bikes

Bottle or Nitrous tank mounting and temperatures...

Nitrous oxide bottle pressure is the Nitrous Oxides own vapour pressure. This is the only thing that forces it into being a liquid. The actual pressure is caused by the liquid trying to boil off.

 Since its in a sealed container, it cant!  This pressure is around 800psi at room temperature. This is the key! TEMPERATURE! The pressure in the bottle has little to do with the amount of liquid Nitrous Oxide that's left in it! 

As long as there is a spoonful of LIQUID Nitrous left it will read the exact same pressure as it does when it's full... 

Now the actual bottle pressure is unimportant, Since you can correctly jet the nitrous system to operate at anything from 600 to 900 psi. But the pressure variation due to cold/hot temperatures alters the amount of Nitrous that gets delivered to your motor. With consistency in mind, you will want to mount the bottle:

• Away from sources of heat. Exhausts, unventilated car boots and interiors in summer time, engine bays, etc.

• Away from severe cold (Car boots get cold in winter too! That's the reason  for bottle heaters!)

Obviously some of the above is contradictory... Common sense will allow you to keep an eye on the bottles temp and pressure. But at least you will keep in mind that obvious problems can be avoided.  Such as a part of the boot floor that gets hot on a long run is a bad choice of place to mount your bottle. And opening the lid when parked in hot sun will help avoid problems! And expecting your nitrous system to work normally after a icy winter morning where the bottles been outside all not going to happen!

The bottle should be mounted with whatever type of secure bracket or mounting you want to fabricate/buy, but it needs to be orientated so that:
 

• As you accelerate the pick up pipe inside the bottle still picks up the Liquid Nitrous Oxide Gas from the bottom!  So generally the valve outlet needs top point downwards, with the top of the bottle facing the front of the car or bike and the "bottom" sitting lower than the top.  Anything from 10 degrees to the horizontal up to and including vertically 90 degrees upright is fine!
  
  Whatever space and installation and cosmetic appearance requires. Remember you will need to remove it often to refill!
   

• For reasons of "prettiness" on motorcycles, people often want to put the bottle in line with the tail piece or seat unit with the valve facing forwards to keep in with the general aesthetics of the bike. This is OK, provided that you fit the pick up pipe inside the bottle so that it ends about 1/3rg of the way along the bottom of the bottle from the valve/bottom edge. But you will never get all of the Nitrous out of the bottle as a result. No problem if you refill or top up between runs at the strip though! I used to do this.
   

• A simple metal bracket with Velcro straps, or rubber straps is fine, or with long "hose" type clips provided it can be easily removed for filling.

The Nitrous Line!
Once you have the Bottle or Tank mounted you need to decide what you are going to use for a pipe between the Bottle valve, and the Nitrous solenoids. This requires a few decisions. One of which is where to fit the solenoids - So read ALL this page before you start!

a) Are you gong to use NYLON 4MM O/D, or BRAIDED STAINLESS pipe? (Or if you are a real cheapskate you can use 3/16ths solid copper brake pipe! - I did this on my brothers V8 car - he was a poor student!) You need to decide so click here...

b) If its easily possible to run the pipe INSIDE the car then this is the best and easiest option remembering that HEAT is a problem! Keep away from all heat sources. Sometimes you will be able to run with the cars wiring loom, sometimes under carpets or inside the plastic trim etc.

c) If the above is not easily possible, or the route too long or torturous (straight & short runs are MUCH better!) then drill a hole near the bottle valve, fit a rubber grommet and route it under the car. AVOID hot things like the plague! Heat causes the liquid to turn to gas! That's bad. You don't want that to happen.

Read Nitrous Feed Line

Mounting the Solenoids - Positioning
Now you have the bottle mounted, and the nitrous line run to where you want to fit the solenoid valves. Requirements:

• Must be easily accessible for maintenance and installation of jets for setting up.

• Must be located as close to the point of injection (injector?) as practicable.

• Must be located in a spot that's cool, and protected from the engines heat

• Must be in a position that allows a short Nitrous Line to be used.

• Must be mounted securely in a spot that is not subjected to vibration like directly on the motor.

Once this spot is chosen then you are in a position to make up a simple bracket or mounting plate. One really good spot on cars is behind the panel at the back of the engine bay where fuse boxes etc are normally located.  Or towards the top edge of the inner wing at the rear corner away from the heat.

Once a spot is chosen then install and connect up the Nitrous Line to the Nitrous Solenoid.

Connecting up the fuel to the fuel Solenoid
There are many types and styles of fuel system and pressures. All that's important is that the CORRECT QUANTITY of fuel is delivered to the engine to suit the nitrous jet used!

On Bikes... See CHART. Some may be gravity fed, others may need to be pumped. This is NOT preferable, just a necessity if any of the following statements happens to be true! If you DO NOT need a pump just fit a TEE piece into the pipe that feeds the carb(s) and connect a extra bit of petrol pipe from here to your Fuel Solenoid. Fit spring type clips. Petrol leaks are dangerous!

a) You want more than 40/45BHP increase? You need a pump. See car section below.

b) You have a fuel tank that is NOT above the carbs? You need a pump but you must already have one! It MAY be big enough already. See car section below.

c) You're bike is blow-through carb turbo, or fuel injected. You need a pump, already have a pump, and it is likely to be big enough!  See car section below.

On Cars... See CHART.

More info to follow!

*Technically the term NOS is incorrect as this refers to an specific company (called Nitrous Oxide Systems, in the US)