Nitrous Pipes & Fittings:
What you need for what, distribution blocks, jet holders,
Nitrous Pipes and
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Tube & Fittings for Bottle / Valve
Fits into the bottom of the valve INSIDE the bottle.
This needs to be from metal "car brake pipe" so any car
maintenance outlet will be able to sell you some. Halfords for
Example. Brass/copper stuff, or Steel pipe is fine. This stuff
is 5mm Outside diameter (or 3/16 of an inch).
This pipe needs
a fitting to connect it to the bottom of your bottle valve,
and this will be a 5mm compression (to fit your pipe) to a
male thread. The male thread needs to be whatever size is
easiest to tap into the bottom of your chosen bottle valve. Or whatever thread
it already has. Example, 5mm compression to male 1/8th BSP. or 3/16 BSP OR 1/4
BSP. Use your brain! Compressed air specialists on your local
industrial estate keeps these fittings.
Bend and cut the pipe so it feeds
from the bottom corner of the bottle with the valve outlet
pointing down when the bottle is in the same position as it
will be fitted into the car. Refit the valve. Depending on
valve type it may use a rubber ring to seal, or chemical
sealant, or PTFE tape. It does not have to be ridiculously
tight! You only need to tighten it as you would a water pipe!
Some people go completely mad here! If you have trouble
undoing the valve from the bottle, use a large vice, or a pipe
vice and a rubber car mat to grip it without scratching it
Plastic large bore siphon tubes,
sometimes fitted as standard, can have massive internal volume
compared to the nitrous pipe that feeds the solenoid, so it is
unsuitable as it may take a long while to clear of nitrous gas
- we want the Liquid!*
Braided Hose - from Bottle to Solenoid &
This is the stuff that you can buy to replace your bike or
cars rubber brake pipe. It is about 3.75mm internal bore. You
can buy this off the roll, and fit the end fittings yourself
Once you see the fittings you can
see how easy they are to fit. Just tighten it up all the way.
These types of fittings can be taken apart and re-assembled if
To cut it to length tightly wrap some insulation tape around
it, and using a disc cutter, or if you are careful a junior
hacksaw will cut it through.
The Pipe and
fittings (Braided to 1/8th BSP) are available from tuning
shops at a price, or cheaply from the sort of people that do
pressure hoses for industry, along with bearings, etc.
Some Braided Pipe, with the
Fittings already screwed on!
The two bits of rubber, are for abrasion protection of the
Motorcycles frame, that this pipe was fitted to.
4MM Diameter Nylon Tubing
4.00 Millimetre diameter (O/D) Nylon pipe, is needed to go
from the solenoids to the distribution blocks or manifolds if
used or/and to the point of injection. This applies to both
Nitrous and Fuel. Get plenty its cheap!
Be careful when
buying, because there is many different internal bores. The
2.5 inside diameter is the most common and so we use this. In
most cases it makes no difference, but on some low pressure
systems, and with bikes on gravity feed the pipes bore is
important. So for the sake of consistency I will only use the
2.5mm bore stuff. This stuff does not like the full bottle
pressure much in full time use, but its also OK for refilling
bottles etc. When in use under your bonnet, it never sees high
pressures, because its used AFTER the control jets. And the
end of the pipes are open to the engines inlet manifold.
At a push and for sub 50 to 70 bhp systems it can be used between the Nitrous
Cylinder and the Solenoid.
Fuel pipe connector for Fuel Solenoid
You will need to connect your fuel solenoid to the cars
fuel system - OR - you will need to connect your fuel Solenoid
to a separate pump/regulator for racing/big Nitrous systems.
Either way you need to connect it up!
1. For low
pressure, carbs at 3 psi to 10 psi - you need a 6MM T
connector to connect to the existing fuel system with hose
clamps. And a 6mm "Tail" with a 1/8th BSP thread to connect
your fuel pipe to the Fuel Solenoid.
2. Race type setups with separate
pump/regulator, will not need the T piece but will need the
6MM hose tail to 1/8th BSP (Solenoid) connector.
3. If at all
possible on fuel injected Vehicles, it is far better to use a
Braided Hose (same as the Nitrous line) to connect to the fuel
system instead of any of the above. This is because of
the 3 bar (45psi) fuel pressure. Hoses with clamps are prone
to coming apart, or leaking at these high pressures unless
fitted by an expert! It is quite possible to tap into your
fuel system (after the fuel pump, but BEFORE the regulator @ 3
bar) with a simple tee piece and some hose clamps. It is done
regularly. But in my opinion its not a very safe practice. Any
leaks or problems and a LOT of fuel will get sprayed about!
Fires can kill, and if not destroy your car! Be warned. If in
any doubt consult an expert. Much better to use a short bit of
Braided hose with whatever fitting(s) are required to connect
up to your cars fuel system, if you can. A little thought, and
a hole drilled and tapped, maybe in the banjo bolt on your
fuel filter, or a T added before the fuel rail will do the job
professionally. Don't use tubing that is not reinforced, or
that may melt easily in the event of contact with hot engine
A 6mm (or 1/4 inch hose to 1/8th BSP fitting to connect
your fuel pipe to your solenoids etc
Injectors or Foggers or Nozzles
Before we get carried away here, I have to say that there
is more bullshit talked about Direct Port, Plates, Foggers etc
than all the rest of the misinformation out there put
I have dyno tested loads of cars/bikes with all
kinds of systems... And some with both. The only thing I can
say for sure is that "AS LONG AS IT GETS IN THERE
SOMEHOW, AND ATOMISES THE FUEL PROPERLY, IT WORKS GREAT!" I can't measure or find
any difference between different Nozzles/Plates/Foggers,
multipoint or single point injection at all! And I have
tried on all kinds of vehicles, so don't worry
about it. (For NOS and other clone, addicts then there may be
some differences simply because they are jetted at the wrong
place... But I digress!)
Now I got that off my chest, lets
see what we actually do need:
1. However you do it, it must atomise the fuel well, and reach
all cylinders in roughly even proportions! You don't want to
feed everything into a single port runner (Extreme example!)
or one cylinder will make tons more power than the rest!
2. It must be as close to the
motor as reasonably possible to prevent fuel dropping out of
the "fog" before it reaches the engine. (This is amazingly non
critical actually, because you only use Nitrous at FULL
THROTTLE, and there's big airflow!) But Keep it in mind...
3. It preferably wants to be
injected right under the carb in the Plenum area, or if fuel
injected, right after the throttle body PROVIDED that this is
close to the engine! If its not, then inject at the last part
of the tube before it enters the plenum area, so that all
cylinders get the same amount..
you use separate throttle
bodies, or more than one carb, then you are going to need TWO
or more "Foggers/Nozzles"
5. On any
engine with a common plenum area or air intake use only
injector. Even with 12 cylinders each one "breathes" in at a
separate time. This ensures more even mixture distribution
than separate "direct port" systems. Because the stuff is
already mixed! And each cylinder will only ever be able to get
a share of the same Nitrous/Fuel/Air mixture. With direct port
systems, variations of pipe length, internal pipe work
restrictions, temperatures, jet sizes etc will ensure that you
NEVER get even power / mixture distribution!
6. On engines where you have no
choice but to use Direct port, don't stress! Its not a
At least on properly designed systems with equal
length low thermal mass nylon pipes and jetted at the solenoid.
You actually don't need a Nozzle or Fogger at all... Just a
couple of simple fittings aimed so that the Nitrous atomises
the fuel properly. But if you want one, then see below!
OR simply arrange the following
situation using simple cheap fittings, and some drills and
taps. This is often actually easier... Works just the same.
This shows a bikes port. The same principle
applies anywhere though. The blue pipe is the nitrous - The
black pipe shows the fuel getting atomised and swept towards
This works just as well. Keep the two streams
close together though! The gas from the blue pipe will still
atomise the fuel and carry it into the motor. The closer
together the nitrous and the fuel streams are the better.
Or if space is tight, like this is also OK.
AS LONG AS THE FUEL AND NITROUS MIX IT WILL BE FINE!
Distribution Blocks for Multi-port Setups
On most bikes (not
turbo) and some cars Multi-port setups (direct port fogger
nozzle) cannot be avoided. In this case you will need some
king of distribution block for the Fuel, and nitrous solenoid,
so as to feed 2, 4, or more nozzles.
These can be bought from the same
compressed air specialists as the pipe, solenoids, and other
fittings cheaply as you need them.