NB: NoS is a brand name of a company but many confuse this
with the name of the gas Dinitrous Monoxide AKA – Nitrous Oxide N20,
Dinitrous Monoxide, Dinitrogen oxide also referred to as Nitrous or giggle gas
(from its medical usage as an anaesthetic.
It was
used in wartime to boost the engines in aircraft and later became
a big hit in drag racing in the Pro Mod class. Not a flammable
gas in itself it is injected into the intake manifold where it
mixes with air & fuel. It rapidly changes from a liquid
to a gas and produces a cooling effect (when you get out of
the bath the water starts to evaporate or turn into a gas vapour
and takes the heat from your body) this cooling effect reduces
the temperature of the air taken in by 60 degrees F. Colder
air carries more oxygen which is flammable.
Then as the Nitrous gas
is heated up in the combustion process it breaks down releasing
additional oxygen and increases the burn rate allowing more
fuel to enter the combustion chamber. Different size nozzle
jets offer larger boosts to the power ranging from 20bhp
more to over 200bhp more. As well as sending Nitrous to the engine you will also need to supply additional fuel (Nitrous provides a cooler denser air charge, more oxygen, so will run Lean if more fuel is not delivered.) Obviously the engine has to be able
to cope with this increased pressure and power so the jets are
matched to the application. Most standard engines can cope with a 20 - 40 bhp shot. Forged pistons, forged
steel rods and a heavy-duty cylinder head with up rated gasket
and performance bolts and full balancing are required if you go for a major
power increase.
A full range of Nitrous delivery systems
are available for all applications of vehicles and engine types
and can be matched to each cylinder in the engine. The common delivery systems are:-
WET (The fuel and Nitrous are mixed and introduced together to the primary part of the intake. This system produces slightly more power than dry but cannot be applied to an engine with a dry intake typically most fuel injected engines.)
DRY (The extra fuel required to maintain the burn balance from Lean to Rich is delivered by the injectors of the car. The primary part of the intake is kept dry of fuel.)
FOGGER (Named after the Fogger Nozzle mixes the fuel and Nitrous mixture and sprays it directly into the cylinder. Each cylinder can be set up separately and additional foggers can be added creating a dual stage kit. Foggers generally produce the most significant power gains.)
A bottle warmer
can assist with maintaining bottle pressure and delivering smooth
power. To get an idea how much Nitrous remains in your bottle you need
to weigh it – as the pressure
gauge just indicates the pressure in the bottle and this can
vary depending on temperature.
It is fairly easy to fit Nitrous to a
vehicle within 4 to 6 hours although most insurance companies will
not provide cover for road use. (As with all modifications your
insurers must be notified.) A 10 lb bottle of Nitrous is good for about
3 minutes of boost (7-10 ¼ miles
runs) but shouldn’t really be operated for more than 10-15
seconds at a time if you don’t want to blow up your engine.
Nitrous can also be applied to diesel
engines a 130ps Golf TDI got almost double the power - but boy racers don’t
buy diesels – well not until recently. Medical
grade NoS does not have a smell added like automotive grade Nitrous (incidentally the smell added to car grade Nitrous is Hydrogen Sulfide, a very nasty additive that will cause permanent damage to lung tissues and nerve endings if deliberately inhaled for recreation!) So you can use medical grade Nitrous in a car but not vice versa!!!
When to press the Nitrous boost button –
At or over 2500 RPM with the throttle fully depressed – you
can buy a progressive boost system which matches the Nitrous shot to
the throttle position and regulates the flow. You will receive
an enormous increase of torque and this can result in a loss of
traction – so be careful at speed as a loss of traction usually
equals an impressive spin and crash.
Suppliers of Nitrous injection systems are:- NOS, Wizards of NOS,
Nitrous Express (NX), ZeX, Edelbrock, Holley Nos, Venom,Nitrous
Solutions and MJS (You will find NOS, NX and Wizards of NOS in
our discount
part shop where you can buy online.)