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Why its jetted @ Solenoids
Why we cant use Oxygen!
V8 into Ford Sierra!
The Nitrous FEED line: From
storage bottle to solenoid. Is
bigger better? Is braided better?
THAT argument again.
Nitrous Feed line size & material.
better? err no... Not this time. No matter what the "expert" racer/tuner tells
4mm O/D Nylon (internal bore 1.7mm
Nitrous line, Versus the Stainless Steel Braided 3.7mm ID
argument... Which is the best one to use with your system.
This pipe feeds Liquid Nitrous Oxide to your Nitrous
Solenoid in the cars / bikes engine bay / area...
These are the two "normal"
obvious possibilities. At least here in the UK.
One is basically the nylon pipe
that air specialists use in factories and machinery. Just pure nylon. Comes in
any colour you want! Great stuff for nitrous Oxide as well.
The other is Brake
pipe. Or that's one of its uses. Its a P.T.F.E. core with a braided stainless steel
protective outer casing. There are generic brands, and big names like Earls,
Aeroquip and Goodridge. Many Nitrous companies make up their own. On the face of it it looks like a simple
question - but its really not! Which is best simple 4mm nylon or expensive
common type - The "brake pipe" type of line, in braided
stainless steel with a fairly big internal bore, and
relatively high thermal mass.
second commonly used type (at least here in the UK) is
the 4mm NYLON Outside Diameter or O/D with quite small internal bore inside,
and very low
thermal mass "cheap" unprotected (no stainless armour
sleeve) Nitrous line...
lines job is to
deliver a constant flow of LIQUID Nitrous Oxide to the
of the Braided stuff...
to look at!
pretty to look at after its been disconnected and
re-connected hundreds of times with quality stainless steel fittings!
and more abrasion resistant because its coated with
stainless steel braiding.
Can withstand very high pressures safely
it has low "gassing" of the Nitrous
(and stays in dense liquid form) as flow increases due to less pressure drop
over the length of the tubing. If the line happens to be full and
cool... Generally its not though. So some of these advantages turn into
inconsistencies in practical use at least for the first few seconds of
It has more
internal volume, which is its largest problem. So a short period of time
goes by when activated, where all the "gas" that may be
sat in the line (not THE REQUIRED liquid) gets pushed out through the Nitrous solenoid
and Jet. This
effect is worse with small Nitrous jets and long pipe
runs. In racing use a "purge" valve can be used to ensure that the air/gaseous
Nitrous is vented to atmosphere before the run, which is wasteful and of little
use in a street type system. A small bore nylon tube almost removes this problem
and is therefore more consistent in use.
looks more "professional" and quality.
mass means it will cause gassing or boiling for longer wherever the
pipe is hotter than the Nitrous leaving the bottle. Again a small volume nylon
only feed pipe doesn't suffer this problem.
difficult to cut and fit the end fittings for if you
have never done it before! But not too difficult.
of the 4mm O/D Nylon stuff...
Its not as
pretty to look at
Its nuts and
olives, and the pipe itself begins to look tatty after
it is undone and redone lots of times!
Its not as
tough and abrasion resistant.
Its cheap! and
can easily be replaced in minutes.
Not actually designed
very high pressures safely. But is "ok" for nitrous usually!
It has MORE
gassing of the nitrous as flow increases. This is due to
the pressure drop over the length which increases with
the flow rate. This means less dense Nitrous Oxide
delivered as the jet sizes go up or the pipe gets longer. This makes it more
difficult to estimate the correct jets without
individual testing. Although once correct it is more consistent than Braided
pipe due to low thermal mass.
It has less
internal volume, so it "purges" the line of gas and air
faster giving faster and smother "hit" of Nitrous.
Little or no need for a "purge" valve.
to cut and fit the end fittings
It is small
so can be run in side wiring looms, under carpets inside the car more
There may be a few other minor considerations but
basically this is what happens. If you are running a low
power system (UP TO SAY 70BHP) in a street car, a nylon line is adequate. It
will perform better than braided and be more consistent.
you REALLY want pretty stainless braided pipe here, with its bigger internal
volume then it will work, but there will sometimes be a
short delay between hitting the button and go! This matters
less with bigger hitting systems (70bhp upwards) because higher power system
purges the line much times faster than low power system! There is
no "yes" or "no" answer.
Horses for courses I am afraid...
Personally for 70BHP and above I would use Braided, routed
carefully away from heat... And on a bike where the line is
short, I would ALSO use braided for 35BHP and above. For all the rest I would
use 4mm OD nylon.