Why we cant use Oxygen:
Why we can't inject pure Oxygen (O2) instead of Nitrous Oxide N2O gas
Why not inject Oxygen instead of
Nitrous Oxide (NOS*)?
There are LOADS of
When you compress nitrous oxide gas into a bottle it goes
into a liquid - It collapses. Its a bit like looking through a clear cheapo
cigarette lighter... With its own vapour or "gas" above
holding it in this state. Liquid is hugely more dense or compact than a
pressurized gas can be. So It takes up massively less
space than compressed gas does and solves its
own storage problems. It also means that the bottle
pressure never changes as the content level varies. Its sits there in
perfect equilibrium. as long as there is at least some liquid Nitrous left.
Only the temperature can change the pressure.
So that means that a bottle that's almost empty has the same
800 psi in it at
room temp as one that's just been filled. We can then jet the
in a simple way and get a consistent liquid nitrous flow
regardless of "how
much is left" in the bottle as long as some is!
It boils off and restores its own 800 psi at room
temperature pretty damned
quick no matter how fast we use it up or leave it stored. It
liquid just like LPG or many other gasses.
atom (technically O1) cant
live on its own it gets lonely. It combines with itself.
So really its O2
(or for short periods O3 or Ozone if you prefer but it
prefers 2 atoms because 3
is a crowd but it cant live just with itself it gets lonely!
Weird or what)
Now O2 or Oxygen as we know it cannot be compressed into a
causes huge problems. You have to cool it really cold to get it
liquid. Now you
can keep it liquid by allowing it to boil off slowly like
you see on TV with
liquid nitrogen. boiling away... Or like NASA did with the moon landing
Saturn Five Rocket.
A bit impractical for a car...
But you can compress it. Unfortunately as you use it the
pressure then falls off
fast. So you need a regulator and regulate the gas that
comes off at
whatever fixed pressure you choose. But it better be a big
are going to need a lot of this gas.
Now even a BIG bottle with say 3000 psi of compressed oxygen
in it is still
very little actual Oxygen compared to the amount of oxygen
stored in a small
bottle of LIQUID nitrous oxide.
b) We inject LIQUID nitrous oxide
at a controlled rate via a
jet into the
intake system. Here it starts to absorb heat from the air in
the cars intake
system causing MORE AIR to be drawn into the intake due to
the rate of
contraction and cooling of the intake air. At least in sane power
So manifold depression actually increases at the same time
as you are adding
more oxygen! Clever trick. And at the same time the charge
cooled. To way cooler than any intercooler could ever
achieve! This charge
cooling and manifold depression increase along with
increased charge density
is where much of the extra power and anti detonation property comes from.
Introducing gaseous oxygen instead does two things... If you
enough to get any appreciable power increase it takes the
place of the
incoming air via the carb/throttle body. Because its not liquefied. So its
"bigger" physically than the nitrous charge.
On the face of it
not an issue. But
unlike nitrous oxide which:
i) does the opposite,
massively. But that's not the worst! That bad bit is that it
both "blocks off"
the nitrogen cooling in the intake and contains none itself.
c) consider what happens in the combustion chamber. With
nitrous we have the
Nitrous Oxide compound in very cold dense form (no free
oxygen here until AFTER compression / combustion!) and we have the normal air (plus a bit
extra since its
now ice cold) and the fuel. Under compression nothing
happens until the
Then as the normal ignition process of air
takes place the NITROGEN absorbs the heat and expands and
Nitrous oxide compound doesn't split up until after ignition
initial charge that's compressed and then ignited is over rich
too. At this time
the Nitrous oxide compound splits! Then it releases 2
nitrogen atoms and 1
oxygen atom from every N2O compound molecule. So now the
freshly released oxygen can oxidise the remaining fuel. And its all very safe
and actually helps prevent detonation.
Now try this with Oxygen instead! You have very little
nitrogen. You have
the fuel. And you have a warmer charge that's very Oxygen
rich BEFORE ignition. Under compression any tiny glowing particles left
over from the
previous combustion cycle, or a hot valve or plug electrode
ignition! Very early! And very quickly. Effectively you
will run over your
own crankshaft. Ever play oxygen on to a bit of hot metal?
Or watched a
science teacher relight an extinguished taper by dipping in
a test tube of
oxygen? Its not what you want happening before the spark!
And even if you
don't run into those problems there are more!
d) After ignition you will have horrendous heat problems.
Because... The Inert Nitrogen (78 percent of air and 64
percent of the split
up Nitrous Oxide) is absolutely essential.
It is this that prevents the horrible detonation and runaway
that your car would have by absorbing the heat generated and
shove the piston down. It is the most abundant gas in the
chamber. And it really does need to be. And remember that
the BULKY gaseous oxygen
that you add to your engines intake system actually
displaces the nitrogen
that would have entered by the throttle plate.
Incidentally I tried it anyway with the oxygen gas from a
welding torch on
an unsuspecting 125 Honda. Sounded awful and emitted many
sparks. Good job
it wasn't mine...
the term NOS is incorrect as this refers to an specific
company (called Nitrous Oxide Systems, in the US)