Nitrous

[clapton924]

It just occurred to me today that I've never heard anyone mention the use of nitrous.  I was watching a TopGear tonight and with nitrous they were able to make a late 90's Jag beat a newer 911 turbo in the 1/4 mile.  I don't think any of us need maximum power (Forced induction) all the time.  If all your looking for is to occasionally track your car....wouldn't nitrous be the most cost effective option?

In the past I thought nitrous was just ricey...something from the fast & the furious....but it DOES make big power. Thoughts?

[wtcii]

Someone had some at one point. Xodus maybe... Not sure about anything else though...

**Edit. I found a picture and it was him.

[Mike]

Its really not good for the motor. Most folks on ECM relay on there cars to get them to and from work more than anything so that is probably the reason for the lack of mods that have the ability to make the engine go boom.

[slipkord]

NOS make you go boom....watch out!

[CrackerTeg]

Yeah, because N2O is flammable. Nitrous can be a good power adder if used properly. The best way to go is with a wet system and of course the tuning to go with it. The problem/ reputation that nitrous got was when ricer fanboys started spraying their stock Honda engines with 100+ shots and popping their motors and not understanding why. If used properly, it can be just as nasty a power adder as any other forced induction but its the only one with an on/ off "switch" so to speak. Factory reliability to go to work, then flip a switch and run with the big boys. Best of both worlds.

[clapton924]

Well, it seems that anything done improperly will result in problems. People running too much boost on a turbo could be just as damaging as too much NO2.

N02 is flammable...sounds like a moot point....gasoline = flammable.

[Icebox]

interesting, id like to see where this goes. maybe some of the more knowledgeable whom build motors could chime in on this one.

[Mike]

Yeah, because N2O is flammable. Nitrous can be a good power adder if used properly. The best way to go is with a wet system and of course the tuning to go with it. The problem/ reputation that nitrous got was when ricer fanboys started spraying their stock Honda engines with 100+ shots and popping their motors and not understanding why. If used properly, it can be just as nasty a power adder as any other forced induction but its the only one with an on/ off "switch" so to speak. Factory reliability to go to work, then flip a switch and run with the big boys. Best of both worlds.

Used properly or not it will shorten the life span of a non "built" motor. I've seen it in boat loads of cars that have come through the shops owned by my family members.

[timot_one]

Good points have been brought up so far.  Using nitrous on a stock motor should be done in moderation and sparingly.  If you start spraying a 100 shot of nitrous, you will damage your motor.  Building your motor to handle nitrous is best though.  There are plenty of benefits with nitrous, but it's not practical to run on a DD.

From my research, it's best to run a direct port kit for n/a motors instead of using a fogger.  The one thing I would recommend is if you do plan on running nitrous, is to use kpro and use a dry kit.  Don't try and cut corners and just get a "kit" without any kind of engine tuning.  You'll run into trouble that way.

[xodus]

^^ direct port is better for the reason that on a single fogger the first 2 cylinders it sprays into always get the most abuse and end up with failure.

[wtcii]

Did you ever spray yours? What kind of set up did you have?

[Skippy]

I've spent a lot of time learning about various modifications and I'll take the time to visit the subject of nitrous for all those interested people.

Any modification requires the proper engine management.  As long as the tuning is good, you're free to do whatever you wish.  You could have an utterly crap setup, but as long as it was tuned properly, the whole mess would run beautifully until something in your utterly crappy setup broke.  The only reason why I (as well as my squad of devotees / groupies) recommend the use of the best parts is so that your equipment lasts as long as your tuning does.

Your chemistry lessons for the day revolve around oxygen.

General chemistry will teach you that air is 21% oxygen by volume, with the remaning 79% accountable to nitrogen and trace gases.  Modern air/fuel calculations are based on this fact and are designed to give the required 14.7 parts of air to one part fuel.

Nitrous oxide works on the premise of liquid / gas dynamics.  Again, from general chemistry, we all know that molecules are closer together when in the liquid phase and as a gas is compressed into a smaller volume by pressure, it will condense into a liquid.  When the pressure is decreased and the liquid is allowed to expand, it will become a vapor again.

Here is where applied physical chemistry comes into play and you all go to sleep.  Nitrous oxide is a gas stored inside a cylinder as a liquid.  The pressure and volume constraints placed on it ensure that it is liquid in the cylinder.  When the liquid is subjected to atmospheric pressure, it vaporizes.

As we all know, engine building relies on the three essentials of motor operation; air, fuel, and spark.  Increase all three per stroke, and you get more horsepower from bigger explosions.

Nitrous oxide works by introducing massive amounts of oxygen into the cylinders with a comparable amount of enrichment fuel.  When the ideal nitrous system is activated, a solenoid opens, introducing liquid nitrous oxide into the intake system.  Upon moving from a highly compressed environment to a relatively uncompressed one, the nitrous oxide molecule splits into two nitrogen atoms and one oxygen atom.  It doesn't sound like a lot, but a TON of free oxygen is liberated from this vaporization.  Enrichment fuel mixes with the liberated oxygen and supplements the air and fuel already being inhaled by the engine.  More air + more fuel = more power.  The use of nitrous will increase the EGT slightly and enrichment fuel must be carefully tuned for to keep the AFR at safe levels.  The importance lies in keeping the mixture from going LEAN.

There are three predominant types of kits on the market: Dry, wet, and direct port.  Applications exist for carburetors, but we're not working on small block chevy's here.



Dry kits inject nitrous only and are the perfect solution for the idiot ricer in your neighborhood who wants to be like Vin Diesel and yell " I'VE GOT NAWWWWWWWWZZZZZZZZZZZ" at the people he shares red lights with".  Dry nitrous kits consist of a bottle, lines, a WOT switch, an arming switch, and a solenoid.  Such kits are cheap, and perform as such.  You press the switch, and the valve opens.  Your AFR goes through the roof and your ECU dumps as much fuel as it can to compensate.  This invariably isn't enough, and you eventually burn up your valves from the heat and destroy a perfectly good motor.

Wet kits are incredibly better than dry kits, and are the staple of the educated market.  Wet kits include a "brain" (microprocessor), WOT switch, arming switch, solenoid, bottle, lines, and supplementary fuel injection equipment (a wet fogger and fuel lines).  When you press the switch, liquid nitrous and enrichment fuel are sprayed from the nozzle, which atomizes both finely in order to promote even mixing of the components.  This mixture is inhaled by the engine and produces power with better efficiency and increased safety.  Is this the best? Nope.  It works for the majority of people though, and I recommend it over dry kits.

The end-all-be-all of nitrous is the direct port injection setup.  It's application specific and there aren't many supported applications, so the majority of these setups are custom fabricated.  Direct port nitrous places a wet fogger in each intake runner, providing each cylinder with its own dedicated supply of nitrous and enrichment fuel.  It is highly recommended that these kits be controlled by an EMS that supports nitrous.  Your EMS decides nitrous use is OK, and it opens the solenoids.  Liquid nitrous and enrichment fuel are delivered equally to each cylinder promoting even power gain distribution and maximum gains.  These kits are very costly and again...hard to come by.  If you're smart, you'll invest the time and money by going this route.


Those are the kits, now here's the rhyme and reason behind why they all exist:

Typically speaking, a "fogger" or nozzle is placed right before the throttle body.  This fogger, wet or dry, injects nitrous into the intake manifold at WOT.  I have a theory on how nitrous destroys motors, and my experience in the field has corroborated that theory.  Honda 4 cylinder engines have a firing order of 1,3,2,4.  At high RPM's, this happens very fast.  The cylinders closest to the mouth of the intake manifold will receive an overcharge of nitrous, while the cylinders farther away will receive an undercharge.  This results in what I have termed "nitrous bias", which destroys the cylinders closest to the mouth of the intake manifold.  Quite some time ago, I assisted my mentor in tearing down an NSX motor equipped with a dry nitrous setup.  The exhaust valves and piston rings on the cylinders closest to the mouth of the intake manifold showed the most damage, while the cylinders at the back of the manifold exhibited the least amount of damage.

This is why dry kits are the worst, since they spray nitrous without enrichment fuel directly into the manifold, preferentially to the front cylinders.  This causes the most damage in the shortest amount of time.  Wet kits are better since they at least inject fuel along with nitrous to keep the cylinders cool and improve the AFR.  This works for the majority of users.

Direct port takes all the guesswork and damage control out of the equation.  When used with an EMS like Kpro, a direct port solution offers the ultimate in control and safety.  The EMS will decide when nitrous use is safe, then it will open the solenoid as well as inject enough fuel to compensate for the nitrous injection.  Each cylinder will receive enough nitrous, and you'll make reliable power.

Note that this extensive elaboration is based upon constant bottle pressure.  Since "ideal" is not "real", you will need to use a bottle heating system in order to receive a uniform charge throughout the duration of your usage.  As the pressure inside the cylinder decreases, so does the flow rate, and that affects your charge.  Heating the bottle keeps the charge uniform as the cylinder is evacuated.

That's my spiel on nitrous, good night.

[thisaznboi88]

that was good reading Skippy

[Mike]

Thank you Skippy I understand a lot better now. I miss these rants they are very educational.

[Skippy]

Just wanted to give a warning to my dissenters that I'm still alive and kicking