Me and flybyludegettingirls are having a discussion. I am not being rude as HE isn't be rude either. BUT, we are arguing in the Prelude For-Sale Parts forum and I think it would be better to move it here, A) Might get some backup/disgreements from other members B) Wrong part of the forum to be posting...
Here's what he said (giving a low down on nitrous)
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direct port nitrous allows you to shoot from 80-225 shot. It uses a fogger system that is drilled into the intake manifold and utilizes a nitrous and fuel line into EACH cylinder seperatly. It shoots the exact amount of fuel and nitrous into each cylinder independently of each other NEVER running too lean or rich in ANY particular cylinder unlike the others shot through the intake...where the #1 cylinder gets the most since its the closest to the shot. The kit uses HIGH flow solnoids for bigger shots and is by far the safest kit for nitrous due to the fuel and nitrous being injected into the manifold.
Nitrous works like this. Nitrous is N2O. at 595° it sepereates into nitrogen and oxygen. This oxygen and nitrogen acts as a buffer and the added oxygen adds pressure and allows more fuel to be added making more power.....Your Thinking HOW the hell does it gain so much power??
Well nitrous is also COLD....its injected into the manifold at a VERY low temp...-100's and cools the intake charge significantly, IN fact so much that a 350 HP engine gains 35 HP just off the intake cooling charge.
Nitrous can be looked at just like an s/c and turbo BUT much more reliable due to the cooling effect it has. It adds pressure and allows more fuel to be shot BUT without the nasty heat. Its also WAY WAY more economical than a turbo and s/c due to it being initially cheaper....and allows you to get the SAME gas milage as a stock engine would allow. making nitrous cheaper than a turbo or s/c no matter how long you shoot. I did the numbers...it came out to 4-6K cheaper in fact.
I agreed with him...
I just didn't agree with the fact that he said that the STOCK Prelude internals will stand up to an 80 shot consistantly. Two of my pistons fried/melted plugs/level 10 tranmission all had to be replaced because of a 50 shot that was used once or twice a week at a track.
Oxygen doesn't add pressure, it lowers the intake temperature like you said. Fuel NEEDS to be added, nitrous doesn't in any way allow more fuel to enter the combustion chamber, it needs it. That's why you need to either A) Get something to increase fuel (ex. fuel rail) B) or a FPR and regulate how much you would LIKE to be mixed. If you don't up the fuel to stable the a/f ratio, then you will run lean (no matter what kind of kit you are using). It is better to run rich (not good either) than to run lean. I've seen more direct port systems run WAY rich because of crappy installs, so be careful.
Nitrous gains horsepower because colder air is more dense, thus, once entering the intake manifold/throttle body (dry shot), you get a better/healthier spark which leads to better/efficient combustion which leads to more power.
80 shot is NOT safe on your car with stock internals, believe me I know first hand. You should NEVER spray near the amount of horsepower once cut in half. Example: Prelude engine dynoes stock around 160 or so. If you are spraying an 80 shot, that is too much 80x2 equals ~160 and it shouldn't even borderline. It doesn't even matter if it's "safer" to run a direct port, than dry/wet.
I've been running nitrous on various cars for the past four years or so and the only engine that I would say running a large shot without any valvetrain upgrades would be a Supra. The Prelude cannot handle more than 60-75 shot of nitrous for very long. I've replaced the stock pistons/melted spark plugs/transmission on my Prelude after three bottles of nitrous at a track. I even had a BUILT transmission from level10 on my Prelude that blew because of a 50 shot.
On different cars I suffered 4-5MPG (tested over 6 months) PER tank of gas while running nitrous ONCE a week at the track. That is quite a bit...
EVERYTHING I have posted is irrelevant, I just want to make sure people understand WHAT they should be doing to watch out for their cars safety. I'm not trying to rain or your parade or keep you from making a sale, I just wouldn't want anybody told they can run an 80 shot consistantly on a Prelude and expect nothing to happen. I am actually helpin ya out
Make sure whoever gets the kit, grab some colder spark plugs NGKs 1 step are PERFECT; might want to upgrade your ignition to retard timing while spraying and to get a better spark because of the added fuel/air. Use the purge before you spray every single time. You don't want inconsistant nitrous because of air bubbles in your main line, it will cause you to run lean.
Pay attention to the paragraph before the last one..."I just want people to understand WHAT they should be doing to watch out for their cars safety.
first off it does add pressure. you saying adding oxygen means YOUR adding pressure. I am an engineering major...junior and its quite easy. Think about it. You are adding compression....more air more power. Oxygen is AIR....yea I know its not normal air but your allowing your engine to burn more fuel due to it having more oxygen. if that wasn't the cause why couldn't we all shoot more fuel in and EVERYONE gain more HP....its not that easy. Nitrous needs higher octane....I am sure your saying DUH.....higher octane is ONLY!!!!!!!! needed when the compression increases....WHY you ask???? cause higher compression pistons on the compression stroke burn at a hotter temp....the fuel needs to resist burning prematurely...HENCE predetonation. Thats why turbo/ SC/ Nitrous applications need to run higher octane fuel....also high compression pistons. What I am saying is all legit and right...I will post up FACTS in the next post about nitrous and what the engineers say about it...
I disagree. Oxygen doesn't mean you are adding cylinder pressures. When the fuel is ignited, THAT heat increases cylinder pressures, NOT the air.
Actually in a direct port setup I'd believe the 80 hp would work without problem. If you hit the button at 3k you could waste the motor. If you hit the button at 4.5-5.5k it's a different story. Also melting pistons would be a result of running lean I would think and if you did a direct port setup like he stated you should (if setup properly) maintain a safe air fuel ratio in each cylinder and avoid the problems you had.
Here you go BRO!!!
At the same time the extra enrichment fuel needed also flows into the engine manifold or port via the other solenoid valve. These solenoids are both wired together, so they always open and close together. The pipes are fitted into the engine in such a way that the Nitrous Oxide hits the stream of fuel entering the engine and finely atomizes it into droplets. This is important as you dont want un-atomized liquid fuel flowing through the motor for lots of reasons, the most important of which is that the stuff will not burn and gets spat out of the back!
The extra power comes from the extra charge in the cylinders, of oxygen and fuel. The extra Oxygen comes from the breakdown of the Nitrous Oxide gas compound, into Nitrogen and Oxygen due to cylinder temperatures and additionally from the powerful charge cooling effect that the liquid Nitrous oxide has on the incoming charge as it turns to a gas. It does this in the inlet tract, as it turns from liquid into gas as it emerges from the injection point.
This point may be a single point say at the throttle body on fuel injected cars, or directly into the inlet ports on most bikes, but the effect is the same. In all cases the charge is cooled, extra fuel is added, and atomized.
This additional Oxygen and fuel in each intake cycle increases cylinder pressures (and temperatures), and therefore engine torque and power, quite drastically drastically!
This was from a page about nitrous on a bike, although the same principles are still in effect...
Originally posted by THATPRELUDEGUY Actually in a direct port setup I'd believe the 80 hp would work without problem. If you hit the button at 3k you could waste the motor. If you hit the button at 4.5-5.5k it's a different story. Also melting pistons would be a result of running lean I would think and if you did a direct port setup like he stated you should (if setup properly) maintain a safe air fuel ratio in each cylinder and avoid the problems you had.
I was running a dry shot setup...
That is how I ran lean. I don't think you could run 80 (direct port) on a stock Prelude bottom end consistantly and for very long. I think it would work, of course, just not for very long...
It doesn't matter if you are an engineering major, makes NO difference really.
Name one thing in my post that disproves what you said?? Quote one thing I said that disproves you and your "theory"?? I was simply making a suggestion from MY own personal experience. The only thing I had a difference of opinion is about oxygen adding pressure. I just made a point, SINCE I have had blown my transmission/pistons/melted my spark plugs out of a BRAND new Prelude with THREE bottles of a FIFTY shot ran through it. I wouldn't run as big a shot or even recommend running that big of a shot without the proper internal back-up that you need (in this case pistons)
It's -127 during the atomization process, I did NOT disagree with you there. If you would like some links on what "atomization" is, email me. Atomization process, when dealing with nitrous, is when the liquid turns to gas. I never doubted you or posted otherwise. Here are the links...
Here's one
The drop of temperature of the intake charge means more airl/fuel mixture can get packed in which helps create additional power. As YOU stated, you are saying it increases pressure, like 'forcing' air into the manifold, this is wrong...It increases cylinder pressure which is what happens AFTER the combustion process, the intake stroke to be exact. Nitrous oxide is 50% more dense than air at the exact same pressure. Rule of thumb mister engineering major...
Density DOESN'T equal increase in pressure, BUT what YOU are saying is that the air pressure is what is making the car increase boost/horsepower/airflow. The invention of the cold-air intake is a prime example. It is almost exactly the same as nitrous, just not as cold, because an engine runs BETTER/FASTER/CLEANER off denser air. Nitrous oxide has this 'charged' effect because it has a higher percentage of oxygen than atmospheric 'air' does. Oxygen is NOT WHAT ACTUALLY GIVES THE CAR ADDED HORSEPOWER, like you have stated. It's the ability of the oxygen to burn more fuel, hence the addition of more fuel required.
The nitrogen actually act as a 'shield' to the increased cylinder pressures which allows stability inthe combstion process.
Detonation is when you are running lean (or when you have little/no fuel during combustion) or too low of an octane of fuel. I agree with you on that statement. Pre-detonation happens when fuel is detonated inthe combustion chamber by the ABSENCE of oxygen. I stated this, and that is the reason why I recommended an upgraded ignition. Too much ignition advance/retard will ALSO end in detonation.
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first off it does add pressure. you saying adding oxygen means YOUR adding pressure. I am an engineering major...junior and its quite easy. Think about it. You are adding compression....more air more power.
Wrong again...
The added compression DOES NOT COME FROM OXYGEN by itself like you said. It's actually the burning of the fuel that created the higher cylinder pressures. Oxygen/nitrous DOES NOT have a direct effect on why cylinder pressures increase.
Do your math and TRY and stop making a fool out of ME. Like I said before, QUOTE ME ONCE disproving you in my posts. You can't do it...
well your school must have really screwed up in teaching you something.
Here it is. A cai gains more HP becuase...LISTEN UP. It gets colder air.
now we all know that colder air makes more power. we can use the simply equation used by the carnot engine.
Qh = W - Qc
Qh being the hot resiviour
Qc being the cold reiviour
W being Work
Now a cold air intake on average gains 5-6 HP....every 11 degrees is 1 hp. so a cold air intake is sucking on average 55-66 degrees colder when the stock prelude already has a cai....I don't think so. I don't deny colder air is more dense. it is more dense cause hot air rises. The cai makes HP through getting colder air and also imporving air flow.
THIS IN TURN raises compression of the engine a slight amount. Power is made by increasing COMPRESSION!!!!!!!!!!!!!!!!!!!!! or cooling the intake charge....whenever MORE oxygen is added to the cylinder it INCREASES pressure/compression!!!!!!!!!!!
think of compression ratio's...we have a 10:1 compression ratio in our lude right.
This means that when the piston goes down for the power stroke it sucks in air from the intake and compresses that SAME AMOUNT to 1/10 of the intitial volume......now when you are say 6000 feet the air is less dense and there is less oxygen...so actually you are making less HP cause you don't have the pressure like you do at sea level and less fuel can be burned...smaller explotion....less compression and in turn you can actually burn a lower octane fuel...ever notice in the mtn's in CO they have lower octane fuel???
So adding oxygen either through an intake or n2o, turbo, s/c whatever is adding pressure and allowing you to add more fuel. there has to be a ratio of fuel to oxygen...thats how turbo's make soo much HP...lots of fuel and uxygen are present.
so In turn increasing pressure or compression increases tempeture in the engine. when I said 10:1 ratio...you actually boosted that up to a higher compression adding oxygen and more fuel...hence making more HEAT... your taking a bigger initial volume and compression the same as before...so more air is getting compressed into the same size....in turn it makes lots of heat and HIGHER octane is needed or you can retard the timing for safety so it doesn't pre detonate.
This is the major concern with n2o and turbo's....the heat while adding so much pressure and why LOW compression pistons that are Forged....pressed together from top to bottum so dislocations in the metal and set up grain boundaries to increase strength in the direction of the piston.......are used...
I could even talk about adiobatic and thermal expansion of engines..and how the area below the graph is work.....
IT adds compression AND HAS LITTLE to do with being cold and making all the power off that
HOW THE HELL DO YOU THINK YOU FRIED YOUR PISTONS!!!!!
Originally posted by imaplaya He comes back with this...
I disagree. Oxygen doesn't mean you are adding cylinder pressures. When the fuel is ignited, THAT heat increases cylinder pressures, NOT the air.
I tend to agree with him...but only to a minimal effect. In essence your jaming more gas (as in the state not fuel) into your cylinder when your spraying NOS. The more gas the higher the cylinder pressure.
That is how I ran lean. I don't think you could run 80 (direct port) on a stock Prelude bottom end consistantly and for very long. I think it would work, of course, just not for very long...
Yeah but do you here your response? You were running a dry setup which IMHO are crap for real power. And you "think" you couldn't run an 80 shot for long on the internals? Why? Because you were running a setup that wiped your motor? Sounds more like sour grapes then a factual statement. If you maintain proper A/F ratio and don't get one the button too early why would it hurt the motor any more or less then a 6-7 psi turbo or SC adding the same hp?
I STILL agree with you, as I said before (and you ignored) to tell me where I proved you wrong in my FIRST POST?
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I don't deny colder air is more dense. it is more dense cause hot air rises. The cai makes HP through getting colder air and also imporving air flow.
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I believe you are wrong (opinionated answer). Dense air has NOTHING to do with air flow and I never said it does. Cold air has NOTHING to do with air flow, like i stated. Cold or hot air traveling from the intake to the throttle body/intake manifold is still the same air. Once it enters the combustion chamber is when everything between hot/cold air matters. Denser air/FUEL INSIDE the combustion chamber is what gives a higher cylinder pressure when ignited. It has nothing to do with what it does before it enter the combustion process. I don't think you understand HOW much of an effect denser air does to an engine. You also just contradicted yourself in the above quote.
Compressing air generates heat, correct? Okay, what is the difference between cold air and hot air in this example? Density. Agreed? It doesn't matter if hot air rises, irrelevant. If you put hot or NOT dense air into a combustion chamber you will actually suffer a performance/efficiency loss. The reason why denser air performs BETTER than hotter air is because you can put MORE colder air into a combustion chamber than hot air. If we go by that known theory, you will make more horsepower because, like you said, more air = more power.
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So adding oxygen either through an intake or n2o, turbo, s/c whatever is adding pressure and allowing you to add more fuel. there has to be a ratio of fuel to oxygen...thats how turbo's make soo much HP...lots of fuel and uxygen are present.
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I agree, I just think pressure and oxygen are TWO different things. First off, the obvious, they are. You are referring to pressure in the cylinder. Oxygen doesn't equal pressure. What oxygen DOES is allows MORE fuel to be burned. Take a common fire in a fireplace, without oxygen, what happens to a fire? It doesn't exist. By adding MORE oxygen (colder air = more air in the combustion chamber) you need/can have an increased spark/ignition of fuel. NOW, that[i/] is what increases cylinder pressure and heat. More fuel burned = increase in cylinder pressure. It has NO direct effect on oxygen, or how much oxygen you have present.
FACT: Denser air combusts with more power than regular 'air' at normal atmospheric pressure.
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This is the major concern with n2o and turbo's....the heat while adding so much pressure and why LOW compression pistons that are Forged....pressed together from top to bottum so dislocations in the metal and set up grain boundaries to increase strength in the direction of the piston.......are used...
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I'm going to disagree with one thing with you on this. Turbos. The heat from a turbo doesn't come from added pressure. Do you know what the difference between a turbo and supercharger are? A supercharger runs of intake air that travels through a belted system (irrelevant), BUT it comes from air that enters the engine from outside of the car, OR an intake manifold. A turbo does this as well, except, the intake air is NOT what gives off heat. A turbo use exhaust gases to compress air and THAT is where you get your heat from, hence the need for an intercooler.
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well your school must have really screwed up in teaching you something.
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Wrong again. Do your research on UT engineering. One of the best (top five) engineering schools in the NATION. So don't tell me it's the school.
Man, like I said before, this isn't a point to really prove you wrong. I just believe in some differences and I think maybe we should move all of our post to a different part of the forum so we can get other people's opinion, whether it be experienced or not the latter. We can go in circles ALL day long, and quite frankly I'm tired of it
I apologized and I STILL want you to quote me in MY FIRST POST saying specifically that you are wrong...
Yeah but do you here your response? You were running a dry setup which IMHO are crap for real power. And you "think" you couldn't run an 80 shot for long on the internals? Why? Because you were running a setup that wiped your motor? Sounds more like sour grapes then a factual statement. If you maintain proper A/F ratio and don't get one the button too early why would it hurt the motor any more or less then a 6-7 psi turbo or SC adding the same hp?
Well I agree. I'm saying, regardless of what setup (direct port/dry) I don't think the stock internals will be able to handle that amount of added pressure for a long period of time. I know I couldn't run a dry 80 shot on stock internals in my Lude.
Maybe it is sour grapes...I wiped out my BUILT transmission from level10 with a 50 shot...Maybe I am just bitter...
Maybe it is sour grapes...I wiped out my BUILT transmission from level10 with a 50 shot...Maybe I am just bitter...
-Austin
The Level 10 issue is a whole other can of worms. I know those guys and although they have lots of great claims their products fall very short in my experience.
I tend to agree with him...but only to a minimal effect. In essence your jaming more gas (as in the state not fuel) into your cylinder when your spraying NOS. The more gas the higher the cylinder pressure.
I think we ended the discussion on nitrous...kinda
It's coming down to the air...atleast that's what I disagree on...
Pressure decreases(p) as tempeture decreases(t) but the amount of gas(n,state of matter) you are putting in has increased. The pressure will go up or down depending on mow much the tempeture drop for how much gas(state of matter) you added.
PV=nRT
simplier
kelvin=temp in c +273
n(molecules of air stock) x t(tempeture or air stock in kelvin)=some number(number#1)
n(not stock) x t(not stock)=another number(number #2)
((#2/#1)-1)x100 is the percentage change in the pressure.
On the whole issue of compression - compression is a mechanical thing. The change in the volume of the combustion chamber of a given engine does not change based on what the heck is inside it. It doesn't matter if it's a lot of fuel, a little fuel, a lot of oxygen, or a little oxygen, or even a lot of helium for that matter though it wouldn't burn. Regardless, when the piston moves it is changing the volume in the same ratio. If the volume of a cylinder goes from 1 liter to 1/10 liter as the piston moves then the ratio would be 10:1.
It would seem obvious to me that the big reason nitrous increases output is because it allows more fuel and oxygen to enter the combustion chamber. If you are not changing the size of the space that it is going in to then you would have to pack it in more densely to accomplish that. Therefore, it would seem to me that it would be due in part to the colder temp of the charge (we all know that colder gases are more dense - ie, CAI) but also in part to the fact that NO2 has a higher concentration of oxygen that the air in the atmosphere so it would automatically make a higher density of oxygen, which is the important part of the air that is taken in, due to this.
it Honestly I gave up on reading all this thread about half way though so I can't address any other arguments... I'm watching F&F at the same time and it's distracting... please don't flame me - it might be lame but it's better than having no movie with import cars.
A couple notes some of which may have been covered. I skimmed the articles, so pardon any repeats...
Nitrous doesn't add pressure. The bottle pressure is higher than atmosphere because of chemical properties. If "whatever" you were injecting wasn't at a good pressure differential, you wouldn't get any flow. Your engine is a pump (vacuum on the intake side). Go get a shop vac and spray water in the intake side. Are you telling me you are increasing the pressure of the intake side of the shopvac? You'd better not or you need to stop your junior year and start as a freshmen again.
Just to nitpick, nitrous splits into oxygen and nitrogen at closer to 565-570°F, not 595°F. I can check my Perry Chemical Engineering Handbook if someone insists on a hard number.
Hot air doesn't rise. Cold air falls (it's denser and thus heavier) and displaces hotter air. I had to do calculations for a brewery exhaust venting system, so anyone wishing to see the calculations on that fact can contact me via email.
On the subject of cold(er) air. One reason nitrous works is the cooling of the intake charge. It's also the fact that for the same volume, it carries 50% more oxygen with it which allows the engine to burn more fuel (if injected!). I don't recall who, but someone said you can put more colder air into a cylinder than hotter air. If we are assume we are comparing a CAI to a "filter on a stick" and all things are equal, this is technical incorrect. You gain power over the FOAS with the CAI because the same volume of colder air is more dense with oxygen, thus you gain the ability to burn more fuel over the hotter air.
As far as turbo vs SC. Without hard numbers being crunched, it's really anyones game as far as who has the lower intake temperature (after being compressed). A psig is a psig so all things being equal, air exiting a turbo (excluding any added heat from the exhaust gasses) at 6 psig will be that of air exiting a SC at 6 psig. Air is a very good insulator, and if it's flowing at roughly 141 cfm (a 2.2L Prelude motor turning 4000 rpm), it doesn't have much time to pick up a lot of heat. My bet is that there is not much difference in outlet air temperature between the two. Here's food for thought: Most SC's boost up to 6-8psig, and several turbo kits are sold (sans I/Cs) for up to 6-8psig. Anything more than that and the SC guys add water injection and the turbo guys add I/Cs. Does anyone have the SCC issue where they did extensive intake air temperature measurements on a JRSC'd car (Civic?). It's been 2-3 years I think.
PV=nRT works great for ideal gases, however, when you start mixing in fuel and nitrous, it's far from an ideal gas.
As far as compression, there are really two "types" of it. Static is easily calulated after you know the starting and final volumes of the cylinder. Dynamic compression depends on valve timing and can thus be adjusted, which is what you do when you retard your timing. If you didn't do that, the cylinder pressures would climb and you'd probably be rebuilding your engine in the near future.
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