Dem_z

iTrader: (1)

1. A bottle or "tank" to store Nitrous Oxide?Specification: Any Vessel that can safely store Liquid Nitrous Oxide, meaning a Bottle/Tank with a 3000 approx test pressure or higher used with a Bottle valve that has a pressure relief valve rated LOWER than this test pressure. It does not HAVE to be a conventional bottle. (For example if you wish to "cheat" you could fill part of a motorcycle frame, Rear swinging arm, or under a cars bonnet maybe the "strut brace" could be used for secret storage)

Ideals: Aluminium alloy, polished, or anodised, or painted in two pack epoxy spray paints and mounted using machined billet bracket, and/or Velcro straps for attractive and professional appearance.??2. A valve for this bottle?Specification:* A full flow, (internal bore 2.5 to 4mm) Bottle valve, usually as used for a C02 bottle. It must use a Siphon tube internally that fits into the underside of the valve to draw liquid Nitrous Oxide from the bottom of the bottle / tank. This Valve MUST have (for safety reasons) an Over Pressure rupture disk, as fitted to all C02 bottle valves that you can buy.
Ideals: Small attractive, chromed or Aluminium alloy Valves preferred for a professional appearance.

3. A special fitting that fits this bottle valve and converts to a normal 1/8th BSP thread?Specification: A specialised fitting that follows the 2.5 to 4mm internal bore of the siphon tube/valve and fits the unique Carbon Di-Oxide (CO2) Valve thread that all these valves use, and reduces the thread size down to 1/8th BSP so we can then attach the Nitrous Line to the Valve.

Ideals: Most of the ones we find or can get easily are brass which goes dull! But, this can be Chromed, for the sake of appearances.


This is the complete "nitrous system" comprising of a CO2 Fire extinguisher bottle polished up, a ?couple of plumbers "threaded reducers" and an 1/8th inch "ball" 1/4 turn valve, length of stainless ?steel braided "brake" hose, modified air solenoid to work at 1000 psi plus, flexible nylon tube and ?fittings to feed the gas to the engine, with home made "injector" all shown above. Not shown is the fuel solenoid/pipes/injector...



4. A braided Stainless steel Nitrous Pipe to feed the Solenoid in the engine bay?Specification: Recommended for all bikes and race vehicles - Normal Braided line. The same stuff countless racers, and motorcyclists use to swap onto their vehicles to replace the Rubber brake pipes! Its actually a PTFE (a sort of plastic) sleeve inside a woven stainless steel sheath. It has a 3.7mm internal bore. It can be expensive, if bought "branded (Goodridge, or Aeroquip for Example) or cheap if unbranded and bought off a roll by the meter. Its all the same for our purposes. You will also need some fittings that are easy to screw onto the ends that go from "braided" to 1/8th BSP. These fittings have a minimum 2.30 mm internal bore.?Alternatively, and for cheapness, with some advantages for small power boosts only, and on some road cars, 4mm Nylon, but you will need the stuff with 1.7mm internal bore. And suitable fittings with nuts and olives. (not the more common 2.5mm bore stuff - its not really up to the pressure!)?Ideals: Stainless Braided pipe! With stainless steel fittings on anything with 40BHP extra added or above, and on all bikes. It looks more professional too.*


5. A Nitrous Solenoid!?Specification: Needs to operate reliably, against up to 1500psi pressure of liquid Nitrous Oxide gas at only 10 volts DC as this is sometimes all that's available due to current drain on small light batteries on race vehicles without charging systems. It must also flow enough Nitrous for the intended power increase. The solenoids I modify are actually intended for compressed air, and after modification flow +140bhp worth of Nitrous Oxide. I t must not "freeze" open, or leak, and must operate reliably over thousands of operations. Needs to be corrosion and vibration "safe"?Ideals: Should be low current drain, light small physically, easy to mount, have 1/8th BSP threads on inlet and outlet.
Stainless steel, or anodised aluminium bodies look the nicest and do not corrode. Magnet wiring and connections should be waterproof.

6. A Fuel Solenoid!?Specification: Needs to operate reliably, against up to 100 psi pressure of liquid fuel @ only 10 volts DC as this is sometimes all that's available due to current drain on small light batteries on race vehicles without charging systems. It must also flow enough Fuel for the intended power increase. The solenoids I use here are actually intended for compressed air. There are many suitable ones, but the seat sealing material must be tested to make sure it does not harden, soften, deteriorate, dissolve in everything from pump fuels, to methanol, and various octane boosters. It must not "freeze" open, or leak, and must operate reliably over thousands of operations. Needs to be corrosion and vibration "safe"
Ideals: Should be low current drain, light small physically, easy to mount, have 1/8th BSP threads on inlet and outlet. Stainless steel, or anodised aluminium bodies look the nicest and do not corrode. Magnet wiring and connections should be waterproof.

7. A Tee piece or other means of supplying fuel to the Fuel Solenoid - depends on vehicle?Specification: Any type of tee piece can be used. Some means of tapping into the fuel pressure side of the Carb(s), or Fuel rail. It must be along with its fittings and hose clamps capable of the flow and pressure required for safety reasons.
Ideals: Stainless braided on fuel injected cars/bikes is safest, used with threaded tee or adapters. This is not always easily done, so a normal hose clamp/rubber pipe and barbed tee must be used. Do this VERY CAREFULLY because if it leaks a serious fire could result.

8. A Jet Holder for the Nitrous jet. (1/8th BSP to 4mm O/D Nylon with nut and olive)?Specification: Simple metal fitting. Male 1/8th BSP to 4mm nylon pipe - Compression style. Best not to use "push lock" fittings here. The 1/8th BSP side needs to be drilled and tapped M5 and recessed to accept a control jet. ?Ideals: Brass, Brass plated with nickel, Brass chromed, or Stainless steel.

9. A Jet Holder for the Fuel Jet. (1/8th BSP to 4mm O/D Nylon with nut and olive)?Specification: Simple metal fitting. Exactly the same as the one above. - Male 1/8th BSP to 4mm nylon pipe - Compression style. Best not to use "push lock" fittings here. The 1/8th BSP side needs to be drilled and tapped M5 and recessed to accept a control jet. ?Ideals: Brass, Brass plated with nickel, Brass chromed, or Stainless steel.

10. Some 4mm O/D Nylon pipe to connect the solenoids to the point of injection?Specification: 4mm outside diameter. Available cheaply in big rolls... In many colours. The normal stuff has approx 2.4 to 2.5mm inside diameter. It is NOT rated for 1000psi pressures, so is not really suitable for the connection between bottle and solenoids, but it WILL actually stand it OK. It is IDEAL for connecting the solenoids outlet to the engine, injectors, or distribution blocks. These are at much lower pressure because the control jet is in the solenoids outlet, and the pipes are "open" at the engine end. And more importantly they have low thermal mass.
Ideals: Pretty colours!

11. Nitrous/Fuel Injector - or occasionally more than 1 depending on engine configuration?Specification: It must introduce the Nitrous into the engine, and preferably the fuel as well. It can be two single connections close together, or a single device that allows both fuel and Nitrous to enter at the same point. In ALL cases the Nitrous MUST "collect" the fuel and atomise it finely inside the port, or air intake system.
Ideals: Must look pretty, be small, and preferably use nuts and olives in preference to "push lock" type fittings for reliability.

12. Assorted brackets and mounting hardware, cable ties, grommets, wiring etc?Specification: Difficult. Every vehicle and setup will be different. Fabricate as required...?Ideals: Solid, tidy, neat, well thought out.
?13. An arming switch?Specification: Any switch that looks cool, sits in your cars dashboard, or somewhere within easy reach on a bike, that allows you to switch "on" or arm the system ready for use. It must be reliable, and be able to cope with 5 amps and preferably have some kind of light or other indicator so you don't forget its on!
Ideals: Use a "standard" interior switch in your car that uses the unused switch positions on your dashboard. This way it looks standard, not obvious?

14. Throttle operated Micro-Switch or other alternative?Specification: Use a GOOD QUALITY 5 amp micro switch, and seal against water with silicon sealant or similar. Mount inside the car so the throttle pedal operates it at full throttle, or on the carb / throttle body instead.
Ideals: Reliable!

Source

Dem_z

iTrader: (1)

What Size do you want? Big is best!

Bikes - Ideally you will be looking for 2lb up to 2.5lb Alloy bottles. These can be painted in any colour, anodised in almost any colour, or polished to a mirror finish like my old one also shown on this page at the bottom. (That's an ex fire extinguisher bottle from my workshop by the way!)

Street Cars - a 5lb bottle is ok for smaller boost levels, but a 10lb, or even 15lb one will last much longer! If you have the money and space to spare.

Drag Race - 10lb or 15 lb will be required. When larger power boosts are needed pressure reduction due to bottle cooling is also an important factor as well as quantity. Bigger really is best for ultimate performance - Use 2 or 3!

Or, for those doing this on the cheap!

ANY C02 bottle that is used to store Liquid Carbon Dioxide gas, like in a fire extinguisher, or a pub C02 bottle is completely compatible! If it works for C02 it will be great for Nitrous Oxide as well -- If unsure of the markings then ASK SOMEONE THAT UNDERSTANDS THEM!

This of course means your sources of bottles is actually enormous! They are EVERYWHERE once you start to notice them! Any C02 Fire extinguisher, is fine! They may be red, or black at least here in the UK. Also welding sets, (electric) use them, so they are in most workshops already... Better still, EVERY Bar and Pub, and restaurant uses them for the beer and soft drinks. Go & look round the back! Chances are that there will be 5 or 6, 14lb to 16 lb bottles with valves just laid about... I am NOT suggesting you steal them, but you could "ask" someone? Other places, are factories, diving places, etc. The CO2 bottles really are all over the place once you start to notice them. And you can also try home brew suppliers, they sell them to the public too.

Obviously old or used bottles will need re spraying, or polishing etc; before they can be pressure tested and certified safe by a fire extinguisher test centre or similar. All these dates are already on the bottles, along with the empty, full weights etc all stamped into the metal.

BOTTLE VALVES...
Obviously most used bottles will not need one because they already have one. Most valves are pretty similar, and have a large bore through them, so they will be fine. They also always feature a "rupture" disk which fails if an overpressure situation happens! For example if you leave a overfilled bottle, or a bottle is left out in the sun too long, the internal pressure may get too high. So rather than the bottle explode, the disk fails and you lose all of your expensive Nitrous! Still better safe than sorry. Only use a valve with one of these "blow off" devices. Valves can be bough from Fire Extinguisher renovation service places, or Welding supply shops, and the people who sell the bottles like the Home Brew suppliers.

SPECIAL CO2 THREAD ADAPTER
A Special Thread Adapter that screws onto a normal C02 bottle valve, and allows connection to "conventional" BSP threads is needed. From the bottle we need to connect a 1/8th BSP threaded adapter to allow us to use commonly available braided "brake hose" type tubing to feed the Nitrous Solenoid. As it happens these are fitted to most CO2 Fire extinguishers. They allow the "horn" to connect to the bottle. Some newer ones are plastic, which is no use to us, but all the rest are brass which is great news! You local fire extinguisher maintenance company can get/give you some of these. When the plastic horn is damaged, they throw the whole "arm" bit away too! The bit they unscrewed is the bit you need! You could buy new ones too from the same place, or from welding/home brew suppliers, or any big tool shops that sell regulators. They are sold as "Regulator C02 adapters", and cost a few pounds. They will need the other end drilling and tapping 1/8TH BSP which you can easily do with hand tools.

Dem_z

iTrader: (1)

Siphon 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. 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 cur 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 & End Fittings
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 very easily.

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 needed.

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 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


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 parts.


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 bull**** talked about Direct Port, Plates, Foggers etc than all the rest of the misinformation out there put together. 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 SOMHOW, 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..

4. If 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 ONE 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 problem.

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 the engine.


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!

smokedmustang

iTrader: (7)

WOW!! Nice write-up!!

Dem_z

iTrader: (1)

5.


Controlling the fuel and nitrous flow
The on / off control is taken care of electrically, as both solenoids (the on off valves) will be automatically 'off' unless an electricity supply is turned on. On a bike this can be the horn or starter button, or a small micro switch on the throttle so as to activate only at WOT (wide open throttle) conditions. An arming switch on the dash, or anywhere accessible is also required so the system only works when you decide to "arm" it..

Actual power increase provided depends on the amount of Nitrous Oxide and additional fuel delivered to the motor, and this will be a fixed constant amount regardless of engine's rpm. The amount of Nitrous Oxide delivered depends on the size of the 'jet' fitted into the Nitrous Solenoids outlet. This jet is fitted into the back of the 1/4" BSP to 4mm OD nylon fitting required to connect the 4mm OD blue nylon pipe to the Solenoid Valve. The best jets to use are 'Weber' carburetor jets available from many places. These are like cheese head screws, with a 5mm metric thread and a hole down the middle! (So if you can drill a hole down a screw you can make your own, as I do now. Actually M5 short stainless cap headed (Allen heads) are ideal jets once drilled. In all cases these jets like Japanese Mikuni jets / Weber jets, are all in Millimeters ID, or bore. So a 125 main jet on a bike is 1.25mm bore.


These cheap plastic 1/8th BSP to 4mm nylon tube push and lock fittings are also available in brass or plated brass and with nuts and olives for greater security, but these work just fine if you keep your eye on them! These screw into the outlets of the two Fuel and Nitrous solenoids One is shown drilled and tapped to accept the nitrous flow control jet* - Actually its a Weber carburettor main jet from the local ford dealership...

Now the fun bit.. Nitrous can give literally as much extra power as you want, with the limiting factor being only "detonation" or physical strength of gearbox or whichever bit breaks first!

Most healthy modern engines can cope easily with a 25% to 40% increase without any other changes. So an average Japanese bike that makes 120 BHP at the back wheel will (should!) take a 40BHP increase easily, (and usually, much, much more!) Lean mixtures and over advanced ignitions are what does the damage. So retard the ignition by a good few degrees to begin with, and make very sure your nitrous system is set over rich to start with. The CORRECT timing and the one that gives the best power will be more retarded than stock settings because you have more everything in the combustion chamber!

This means effectively higher compression. This also means that less initial advance will be needed as the oxygen rich, more densely packed cylinder also burns much faster. The faster pressure rise means a more retarded ignition will be needed, to prevent detonation. Also use smaller plug gaps with stock ignition systems, colder plugs, and higher octane fuel all to prevent the possibility of detonation. Just in case!


Download: http://www.diy-nitrous.fsnet.co.uk/Jet_Sizes_2.25.pdf

Buy a cheap small drill set! And a handheld "pin" drill. Now you can drill ANY jet you might want in a couple of minutes!


Tiny M5 Alloy anodised Allen screws make excellent jets! (If you cannot buy the Weber ones locally. Remember a "jet" is simply a screw with a small hole in it, that's all! Nothing technical here!

Now using my chart you can see that its easy to work out how much fuel you will need for any given nitrous jet size. But remember that this is a safe/rich guide only on most non turbo motors. Weather you get this fuel volume delivered by low pressure by a big fuel jet, or by using a very small jet and tapping into the fuel rail on a modern fuel injection car (3 bar) makes no difference!

The fuel flow is controlled via a similar jet in the same position in the fuel solenoid. At 10 psi regulated fuel pressure the correct fuel jet is about the same size as the nitrous jet used - but every installation is different. Mixture setting : Read this carefully!

A single injection point usually gives better distribution, as flow is constant and each cylinder inducts at different times. No jets are needed at the injection point only the ones fitted at the solenoids are required. If more than 1 point of injection is used then a distribution block or several tee joints will be needed. All pipes going to the injectors must be the same length.

Inline X2 X3 and X4 plastic push lock fittings are available for the 4mm plastic / nylon tube and these are ideal, but several tees are also ok - see pic! All compressed air/pneumatics dealers keep these kinds of fittings for industry.

Pipework from Solenoid Valves to Engine
Inlet manifold or cylinder head or carb rubbers must be tapped M5 to allow the fuel and nitrous injection points to be added. Fittings with a nut and olive or push lock fittings can be used, available for industrial airline or hydraulic system use. These fit the ends of your 4mm OD nylon pipes and have an M5 male thread. The Nitrous ones must be fitted in such a way as to atomize the fuel and carry it into the engine. This may require a little thought before you drill any holes!! It may be possible to use just one nitrous and one fuel injector for the whole motor or a pair of each, if fuel injected or turbocharged, depending on layout and throttle bodies etc. Bikes will normally need to have one Nitrous and one fuel injector per cylinder, unless turbo-ed.

A single injection point usually gives better distribution, as flow is constant and each cylinder inducts at different times. No jets are needed at the injection point only the ones fitted at the solenoids are required. If more than 1 point of injection is used then a distribution block or several tee joints will be needed. All pipes going to the injectors must be the same length.

Why jet it at the solenoids outlet instead of the "Foggers" ???

Lots of people keep asking why it is jetted at the solenoids themselves rather that at the point of injection (as all US based commercial systems are). HighPower Nitrous systems & Akamoto Nitrous Systems are also jetted at the solenoids as we all understand why this is far superior. HighPower did this first, well before anyone else did. Me, I just looked and saw all the advantages!

THE REASONS? Basically as follows:

Fuel 1st ? Firstly there is no air or anything in the fuel line before the solenoid. So it does not atomise at all here - JUST SOLID LIQUID FUEL - the jet just controls the flow. It does this equally well if at the point of injection, (Like NOS etc) or at the solenoid's outlet.

If there is any air in the lines after the fuel solenoid due to the pulsing from the motor as different cylinders induct at different times, - (and there will be) - then the fuel cannot reach the motor until it has pushed all this air through the small fuel jet at the inlet manifold end (nozzle?) on US style systems. This increases the time it takes to for it to arrive at the motor. This means it can go lean for an instant, when you hit the button on US style systems. This can start destructive detonation off nicely even if you dont notice the delay. Or it can result in an instant intake backfire as you hit tha Nitrous button off the line, due to the initial weak mixture.

If it's jetted at the solenoid's valve outlet instead, then the correct flow of fuel starts straight away as there is no restrictive jet at the end of the line that you have to first push all the air through.

If you are trying to get reliability and consistency then the nitrous too must be jetted at the solenoid! Here the jet is controlling fully dense liquid Nitrous Oxide direct from the bottle. It is still liquid as the solenoid is supplied by a larger pipe than its rated flow and it is cool, not attached to the hot engine or going through hot areas... If the metering flow jet is installed here then you are measuring a known quantity and density of Nitrous.

Alternatively if you fit these metering jets near the hot (especially at the srip in summer!) motor / engine bay then the pipe work after the solenoid is both long and hot due to the engines heat, and the hot engine bay area. This is much worse when sat on the start line due to zero airflow. Nitrous (no longer sat as a liquid at the correct pressure to keep it liquid in the bottle) is in a long pipe hot pipe! So it boils, expands and "foams" as it travels towards the metering jets on the engine. So you are now metering what? A liquid? Or Gas? Or a VARIABLE mixture of both! In reality in unknown and varying proportions depend on temperatures and length of the pipe work etc. Eventually (a few secs with low thermal mass nylon tube) the pipe is cooled so the liquid now flows all the way to the metering at the nozzle, and you get to meter a much more dense liquid so it runs leaner later on... So it is far more accurate to meter it at the solenoids outlet where it is still a liquid. Here the density remains pretty constant at all times.

Fitting the metering jets at the "end of the line" will obviously work, as all the US based NOS / Nitrous Express etc; systems show, but it is simply not as good a solution. I know I tried it both ways and did lots of testing. Plus... More importantly still:

If you decide to use a Nitrous controller that pulses the solenoids to control the power, with the jet fitted directly to the solenoid the amount of nitrous you get is proportional to the length of the pulse width. So 50 percent open time will give half the Nitrous flow..
If the jetting is at the inlet manifold end / port, then the size of the solenoids seat is the limiting factor - not the jet, as the pipework becomes a Nitrous "reservoir" that the solenoid just keeps topping up...

This means that for example a solenoid rated at 150bhp maximum flow would flow around 75bhp of Nitrous at a 50% pulse width. If the jet on the end of this pipe is a 25bhp jet for e.g., then the solenoid just keeps topping up the reservoir, (the pipe work) so you would get about 20bhp at a 50 percent setting! This is not too serious unless you consider that the fuel is not compressible so it will be giving a true 50 percent... Melted pistons anyone??

ANOTHER DESCRIPTION!

This was in reply to an email question...

Because in the beginning there was NOS.

Then came a massive multitude of clone systems designed by someone without a brain!

Trevor Langfield (The Wizard of NOS or High-power Nitrous Systems) also jets at the solenoid - he did it first. Here is why...

1) Fuel line gets full of air as the fuel drains out of the (oversized) line. Now when the solenoid opens it has to push out the air first, sometimes taking a full second! During this time you are metering only air. And because of the often hot (engine bay in summer!) lines it gets worse! The fuel can boil and vaporise alomg the hot line and some jets get fed only fuel vapour for some time! And the higher the thermal mass of the often metal braided lines the longer this happens for. So apart from the air being in the way, the temperature also makes a difference! Sometimes a very expensive (nitrous only = backfire) one!

2) The fuel line isnt the only problem! The nitrous line also has problems. Now on a cold day the liquid nitrous will most likely stay liquid (mostly) all the way to the jet. Except that it gives off gas (boils) as it goes from the solenoid into the lines and boils off further as it goes through distribution blocks etc. Add to this the fact that the lines are hot in summer under the bonnet, and you can see that you have no real idea quite how dense (how "liquid") the foaming nitrous oxide now is! Its density varies between pure dense liquid, and pure gas. And everything in between. Remember you are trying to meter the weight of Nitrous delivered accurately! But are you metering vapour, gas, or a mixture of the twe? Who knows. It depends on Pipe volume, Pipe thermal mass, pipe temperature. Pipe internal volume. Now to keep accurate control of the mixture from when you hit the button. After the nitrous cools the line down (by the very act of boiling off and reducing density) it will eventually reach the jet as a say 90 percent dense liquid. All depends on too many things!

Typically what happens on a cold day / cold engine bay is this.

Press button LIQUID Nitrous reaches the engine in say .3 of a sec, because its all cool. You meter the full 100bhp of nitrous. The fuel though takes up to a say half sec (or more) to push all the air out of the oversized lines through the jets before it arrives. So initially very weak mixture that can start off detonation that never goes away! Or could cause a weak intake "backfire"...

Hot day/engine bay. Hit button. Fuel gets there and is flowing properly in 0.5 but the nitrous takes ages to "get going" because you are only metering gas or vapour (thousands of times less dense) for anything up to 3 secs! You see this a lot. Recognised by a puff of black smoke at launch. It just costs performance.



Solenoids - Details..
The Solenoid valves that I use are available from the same type of industrial compressed air / hydraulic suppliers as the other fittings and nylon tubing. They are quite common in factories. They have an inlet at one end and an outlet at the other so are axial rather than the NOS type. This is neither an advantage or a disadvantage as I see it.

The fuel and the nitrous are both "jetted" to control the amount of power increase given. The jets are in the form of a simple carb type jet, in this case a weber carb jet, and these are fitted into the rear part of the pipe fitting that screws into the outlet of the fuel and nitrous solenoids.

All are drilled and tapped to take a "control jet" and are standard easily obtained fittings. The all plastic one is cheapest and cannot corrode, and has low thermal mass but the brass one is safer as it uses nuts and olives to hold the nylon pipe rather than simple push/lock fittings. All accept 4mm nylon tube, and are male 1/8th BSP thread, to fit the outlets of the solenoid valves.


A simple nitrous injector/or nozzle. It has no jet. That lives at the solenoid outlet, this simply has to direct the flow in such a way as it collects and atomises the fuel as shown in the diagram. The nitrous must atomize the extra fuel well. The shiny bit is just a bit if brass tube from a local model shop, with a small 2mm hole drilled in the side, and the end soldered up. The plastic fitting has a M5 thread tapped in the bottom, and a 5mm grub screw screwed into it. This was drilled to accept the brass tube, and was all soldered together and tinned to make it silver at the same time.



Ok, for a clearer idea here is a fake inlet port or throttle body I made earlier! See the small hole in the side of the brass tube? it simply directs the nitrous down the port towards the engine. The fuel is added in front of it, so the nitrous collects it and atomises it. These fittings are a bit big, but I made them just for the photograph, for clarity. In reality I use various different methods to achieve the same result, and in any case small M5 fittings. Often two small fittings can be fitted angled together slightly to achieve the same effect without any brass tube...




This was to begin with, so only 70 BHP extra. This meant a 1mm Nitrous Jet fitted into the fitting where the blue pipe is, and a 1.3mm jet fitted into the outlet of the fitting where the black pipe goes in the fuel solenoid valve. This was at 4 to 5psi of fuel pressure that also feeds the twin SU carburettors. The fuel solenoid was simply teed into the supply pipe. The nitrous solenoid obviously connects to the bottle in the back! (In this case with braided brake pipe.) Both of the 4mm pipes seen here are teed off (split two ways) to go to each one of the two carbs. In this installation the carbs were tapped and drilled in the bottom of each "mounting flange" so nothing could be seen! The solenoids were mounted near the cars fuse box and were not noticeable...
It really IS this simple!



A typical example for a bike motor drawn but same principles apply to any engine!

Dem_z

iTrader: (1)

Continued...

They are available in all normal AC voltages, and also in 24v dc, 12v dc, and 6v dc. Although these may need to be ordered.

For our purposes we will need one completely standard 12v valve (above), to use as our fuel solenoid, and one 6v dc one that will be modified internally to work with up to1,100 psi (rated at 150 psi only as stock) These valves have a 3mm or 1/8" inch internal bore or flow, and a brass seating with a neoprene sealing 'washer' for want of a better description, and 1/8th BSP threaded female connections for inlet and and outlet. They work the other way around to a conventional household tap, in that the pressure in the bottle actually holds the valve shut and the 12v or 6v magnet has to lift against the pressure to open the valve. This is why we choose to use a 6v magnetic coil instead of 12v as it draws twice as much current when used on a 12v system as it should, and produces twice the 'lifting' force to help try to lift the washer/plunger off the seating against the 5x normal working pressure. This closing pressure that the magnetic coil and plunger works against depends on the pressure in the bottle, and the area of the seat that the valve covers.

Our fuel flow solenoid is the stock 12v dc valve as it comes. The sealing material is safe with all alcohol and gasoline's and octane boosters and can flow plenty of fuel for our purposes. So just leave this one well alone!

Our Nitrous solenoid will be exactly the same kind of valve (but with some internal modification) but with the 6v dc 'electro-magnet' instead of the usual 12v one. We must however replace the soft 'rubber valve seal' that fits over the seating, with soft nylon, or PTFE bar machined to fit (or amazingly, a BIC biro blue plastic end cap works and fits great! without any machining and if you buy a box of pens you have loads of spares!) .

This is very fiddly work..., but must be done as the stock rubber material absorbs liquid nitrous, which turns to gas rapidly when the valve is opened blowing little bits out of it. After a few dozen operations it will leak...

Once you have done all of this and connected it to a 800 psi Nitrous bottle, you may expect it to work when you add 12v dc to the terminals..... It won't open however, as the pressure of the gas holding the plunger down is simply too great for the magnet. This is because the valve has a full 3mm seat ID (1/8th inch) which is far too big! The solution is to drill this out and replace it with a new brass seat that can be a screw / soldered / push fit into the place where the old one was removed. This sounds complicated but in reality is dead simple. The new bore needs to be 1.4mm maximum (giving a maximum of 139bhp extra) with a very narrow seat area - similar in shape to the one you drilled out. If the seat area is too wide the valve will hiss when you connect up and try it, but not open fully. This is due to the gas rushing between the seat and the washer causing a low pressure area, stopping it lifting any further.

Some bloke with a name beginning with a B (long time since I was at school now) discovered this while blowing between two apples apparently... Why the hell would he do this? Beats me.

(Update... he was called Daniel Bernoulli! apparently!!)

Finally make sure that the 'lift' on this plunger is about 1.5x the bore of the new seat you fitted (1.40 x 1.5 = 2.1mm total lift)

Pulsed controllers...

I did try all this of course.
But, I decided that it was not worth the extra complication and expense on a simple cheap basic system, at least not for my purposes....
It works OK, but its easier just to use two stages or even three - WHEN THEY ARE CHEAP AND YOU BUILD THEM YOURSELF!

Stage one say 40bhp (A single nitrous system)
Stage two say 80bhp (Another single pair of solenoids but jetted for twice the power)
Stage three open both the above pairs together...

First one on the throttle micro-switch, second bigger on the starter button, which cuts off the first stage. Third one (both stages) on the horn! You just need a couple of relays and some careful wiring. The arming switch disables both the starter and the horn of course, and changes the buttons over.

All into the same eight injectors, just tee together just after the solenoids. 3 stages from 2 pairs of solenoids...

But when I did try it (Pulsed controller circuit to vary power) I used 555 timer chip, solid state relays, variable frequency (to see what worked best - seems to make little difference actually) and variable pulse width to control power. The only bit thats not proportional is that at "around" 85 percent (depends on jet size, valve orifice area, volume in between) "on" you get almost full flow because the small space between the solenoid valve seat, and the jet acts as a reservoir... (This is also the reason that NOS style systems with the jets at the injectors are crap when pulsed!!!) The fuel is not compressible so it doesn't do this. So... it gets richer from 85 percent onwards which reduces power a little from this point upwards.

This effect is worse the smaller the jet size of course. In extreme cases a 25 bhp boost can be obtained with only a 30 percent on duty cycle! (NOS kit tested with big old solenoid and braided hose)

Dem_z

iTrader: (1)

6.


Required Parameters

You can use any locally available pneumatics valve if it fits the following specs:

They must have a 1/8 inch (3mm) or bigger internal bore at the smallest place - the "seating" inside.

They must be simple two port type valves.

They must be 12v DC

They must be 1/8th inch BSP inlet and outlet threads.

They must be VERY reliable at 140/150 psi for engine safety.

They must not leak!

They must have sealing materials and gaskets that are not effected by Petroleum based fuels, alcohols, ands all fuel additives



SOME DETAILS...


Here is the piston that the electro (12V) magnet "lifts" up against the working pressure when you activate the Solenoid(s). This is the reverse way round compared to a household tap "washer and seat" arrangement. The top one has been modified to work with Nitrous Oxide at high pressures. But the bottom one is from a standard air solenoid as purchased. This works just fine for fuel as it is!

The seat material and the valves "gasket" rubber seal, have been tested in a mixture of pump fuel, aviation fuel, race fuel (C16), octane boosters (mixed) methanol, ethanol, diesel, paraffin, nitro methane, nitro benzene, propylene oxide.

Over a period of 3 months of "soak" tests, in a jar, the seat material (some kind of rubber possibly NBR not sure) did not swell, soften, harden, change colour or change any of its properties as far as I could tell! This is important! If it fails you could kill an engine... Nitrous without fuel spells disaster.

Interestingly an old NOS (Nitrous Oxide Systems manufactured) fuel solenoid from 1985 fails this test with the rubber "swelled" up and expanded. This when operated then does not lift far enough off the seat to allow full fuel flow! Now you know why I sort out my own stuff...

If your solenoids are not the same make as mine, I suggest you mix all these items together and seal the piston in a bottle or jar with them inside for an extended period and try it! See what happens to the materials... If it blocks the seat up, swells so the valve does not open properly or whatever your engine may be melted! Be extremely cautious...


Here is a stock Solenoid valve as I used to use. It is a simple 140PSI air solenoid valve with a 3mm or 1/8th inch seat cross section. It only requires two fittings! These are shown, one is a "tail" that allows a hose (fuel pipe) to connect to it. That's the thing that at the bottom left! The other fitting is shown below.



This fitting is plastic. The best ones to use are plated brass or plain brass, or stainless steel if you can find them easily. Chromed ones and annodised ones are available too at a price! But use the ones with nuts and olives! The one shown is "push lock" - for simple prototyping great! But these are really only suitable for testing. After a few months at extremes of temperature under a car bonnet, they age, and the pipes can fall out! This fitting (now also the jet holder) goes into the solenoids outlet. The other thing is the brass fuel control jet.


Actually its a 130 Weber carb jet (1.3mm) in this case. It needs to be drilled and tapped and recessed into the fitting rear face as below pictures show! This fitting is 1/8th BSP to 4mm O/D Nylon pipe.

Once its screwed in fully and "flush" it can be fitted to the solenoids outlet. Fuel solenoid is completed! Simple stuff... Ten minutes work.

smokedmustang

iTrader: (7)

HOLY CRAP DUDE!!! Are you typing this that fast??? Do you have a Nitrous hose injecting the "giggle juice" into a tracheotomy hole? MY god, you are doing one hell of a write up!! Might need a manacure though. I am going to read all of this soon, looks interesting! THanks!

Dem_z

iTrader: (1)

Well I didn't want people to comment before the whole thing.. so everything's pre-fab'd to copy and paste fashion for 20k characters. And see source, because that's where the info's from.... Just minus the crap that won't apply.

Everyone complains about me talking about how cool nitrous is... Fast and Furious messed this whole thing up... So I don't expect too much response.

smokedmustang

iTrader: (7)

AWESOME JOB!! Thanks for posting this, should be worth a sticky! MODS, you can take out my comments in the middle,(please) it kind of wrecks the story!

TheShortBus

iTrader: (14)

good write up though!

lancerman360

iTrader: (3)

nothing wrong with nitrous, except it causes this to happen on our motors........https://www.evolutionm.net/forums/sh...hlight=nitrous

Dem_z

iTrader: (1)

You have to run nitrous on a higher octane fuel. Same concepts as a Turbo'ing... I don't know why lancer owners don't know this.... Saying Nitrous doesn't work, is like saying Turbo's don't work.... Both force feed 02 into the engine...

The Nitrogen allows for better cooling, so you can technically get more power out of N20 for the given octane versus just forcing 02 in.... It was bad luck that people boost and their engines messed up. They probably needed to remap atleast.

----
If you say it doesn't work with lancers, post why.

N1te

iTrader: (12)

It doesn't work for our engine... unless you have forged internals, lancers will go kaboom.