Definition of forced induction

Just been having a lively debate with some friends regarding whether Nitrous is classed as "forced induction" or not. VE got thrown into the equation along with BMEP, CFM etc etc.

Can anyone enlighten me ?

Is there a good definition for "forced induction" ?

VE uses "air" in its equation, but does not consider the composition of air hence the ability of nitrous in the "air" to break down give more oxygen per volume.

I feel this would make an interesting discussion

i would say that in the phrase "forced induction" the first word (Mechanical) is silent. so supercharging (including exhaust driven) and thats pretty much it. no ram air and no N2O.

playing devils advocate...

you say "mechanical" is "slient", isn't Nitrous "chemical" based BUT also "silent" ? and both are forms of "forced induction" ?

One of the primary factors affecting engine performance as the ability to get as much of the air and fuel mixture into the engine as possible. It can be thought of as the engines ability to "inhale". In order to produce power, an engine requires a fuel and air mixture to be mixed together and then brought into the cycle. The concept of forced induction is essentially a method wherein we literally compress the air before we bring it into the process of combustion. So basically, think of an engine as a person who is gasping for air after a long run down the street. This person is gasping because they are trying to circulate as much air as possible through their lungs. Now imagine if you were able to force more air into their lungs then they would otherwise be able to suck in on their own. This would in turn help them out very much. In fact, it would help them so much that they would probably be able to run for allot longer without having to stop in order to "catch their breath". In turn, this would yield greater performance. So basically, you can pretty much parallel this idea to an engine. The more air you get into it, the more performance you'll get out of it. This is where the concept of forced induction was derived. While different systems have been designed to achieve the same result (e.g. Nitrous, Superchargers and Turbo Units) the Turbo unit seems to have dominated. In brief, the systems differ from one another in the means by which the process is powered. The turbo unit works by making use of exhaust gases in order to compress the intake while the supercharger mechanically translates the engines rotational power in order to do the same job.
Nitrous is a chemical process.
All 3 are a means of forced induction, 1 using exhaust gases, 1 using mechanical means and the other chemical, and all accomplish the same thing, providing more oxygen to the engine.

only turboing and supercharging is forced induction....N20 is not
I believe Schister is right.
Also--Various auto racing rulesmaking bodies have classed nitrous as a substance that alters fuel and/or combustion chemistry--not as a form of supercharge or forced induction.

Correct me if im wrong but i dont think of chemical injection as forced induction. Now would nitrous be considered chemical as it is just a way to get more OXYGEN into the cylinders? i dont think that either. i think one of the major requisites of a system to be considered forced induction is that it must force air into the cyliders. nitrous doesnt do this because it uses the vacume created in the cylinders to suck the nitrous oxide into them. (or a supercharger pushes it into them)

Well a 50 shot theoretically makes 50 more HP. So it has the equivalent of 5lb/min of airflow. Somehow 5lb/min of airflow extra is being ingested by the engine.

We should just come to an agreement on classification on all of these tho. I say power-adders.

I would say forced induction is when you force the engine to intake more oxygen. this isn't the same as facilitating the intake (higher flowing intake etc) but forcing the engine to intake it. now since i said oxygen, nitrous would fit into the category, you are forcing the engine to get more oxygen because you are injecting an oxygen rich chemical into the intake.

well you are injecting oxygen into the intake but not forcing it into the cylinder. the cylinder is still sucking it in instead of it being FORCED in.

i would say that in the phrase "forced induction" the first word (Mechanical) is silent. so supercharging (including exhaust driven) and thats pretty much it. no ram air and no N2O.
Now your 1st statement says no ram air and no N2O

Correct me if im wrong but i dont think of chemical injection as forced induction. Now would nitrous be considered chemical as it is just a way to get more OXYGEN into the cylinders? i dont think that either. i think one of the major requisites of a system to be considered forced induction is that it must force air into the cyliders. nitrous doesnt do this because it uses the vacume created in the cylinders to suck the nitrous oxide into them. (or a supercharger pushes it into them)
Your 2 post kills you 1st post. Doesn't ram air force air into the cylinders. You speak with a forked tongue white man.
Correction #2 if there was no vacume at all, nitrous would still be injected into the intake. What about blown (supercharged) cars with nitrous...Hmmmm, no vacuum.

Anytime you force a engine to take in more oxygen than available to a N/A engine be it with ram tuning or whatever you forcing the induction system of that engine to provide more oxygen bearing air to the cylinders.

on your first correction, yes ram air does force more air into the engine but not by mechanical means.

on your second correction, even on a blown nitrous engine it is not the nitrous that is forcing itself into the cylinders, it is the supercharger forcing it in there.

on your first correction, yes ram air does force more air into the engine but not by mechanical means.

on your second correction, even on a blown nitrous engine it is not the nitrous that is forcing itself into the cylinders, it is the supercharger forcing it in there.

Although when I first started reading this thread I would have agreed with you, after more thought I believe Zgringo is right.

Firstly, I can see why you would think ram air is not a mechanical device (no moving parts etc.) but I think it is. Would you consider a pitot tube or even a venturi a mechanical device? I would.

Secondly, if the point of forced induction is to get more oxygen (as apposed to air) into the cylinder, than Nitrous Oxide would defiantly be classified as a form of forced induction. I think we would all agree that Nitrous Oxide is a chemical method not mechanical.

So why not seperate forced induction into two or more subcategories such as:

FORCE INDUCTION
- Mechanical Induction
- Chemical Induction


In this way all devices that create a more oxygen rich cylinder condition are covered?

i would be more likely to say that ram air is forced induction before i would say nitrous is, and after some thinking i was almost ready to consent that ram air was. But, i still think that to be considered forced induction there needs to be active mechanical compression of air, and i dont consider pitot tubes or venturies to be mechanical or active. they are passive and are entirely dependant on the speed of the air that is already moving through/around them.

6psi of boost is "condensed air". a 50shot of nitrous is "condensed oxygen".

good point...

But N20 is not "FORCING" anything....its just a "fuel"

Turbos and superchargers are forcing air under pressure into the cylinders

First off Nitrous is not a "FUEL".
Secondly, Nitrous is being "FORCED" into the intake under 500PSI.

Time for class.
Have any of you heard of ram tuning? I don't think many of you have, and even less understand how it works.
Were going to supercharge (turbo) a N/A engine without the benefits of a supercharger or turbo. Just shutup and listen.
Newtons law says, "Things in motion tend to stay in motion."
Now you have to use your imagination.
Think of a 2" tube going to the intake valve. Now this tube is 12" long. When the valve opens the air rushes in the tube into the engine at a hi-volocity and when the valve closes, because of Newtons law, the air is still in motion and stacking up against the intake valve creating pressure, so when the valve opens there is a positive pressure there.
Now if you use a 24" tube you have a larger amount of air in motion.
The idea is to have a tube just the right lenght so the air rushing int the tube reaches it's peak just as the intake valve opens. If the tube is too long the pressure is still building when the valve opens. If too short the pressure has max'ed out and decreasing, it has to be just right for the engine RPM's.
Nothing mechanical here, but it's forced induction.

The problem is a few think of the word "FORCE" as something physical or mechanical. Lookup "Force" in the dictionary, it say's, Force of habit, force of nature, police force, break open or pry. I don't see one thing mechanical in there.

Now nitrous is injected into the intake under 500+PSI, I can't for the life of me see how you figure the engine is sucking it in. When the intake valve opens it's there and goes in.
Same with a supercharger (turbo), when the intake valve opens it's there and goes in.

How the pressure of the supercharger (turbo) got there.
How the nitrous got there.
How the pressure of the ram tuning got there.
It was "Forced" there.

But N20 is not "FORCING" anything....its just a "fuel"

Turbos and superchargers are forcing air under pressure into the cylinders

nitrous is not a fuel, it's an oxydiser. you're not burning nitrous, the nitrous is breaking up into it's elements (Nitrogen and Oxygen) and aiding combustion.

This thread is quickly becoming stupid.....

Zgringo
It's only become stupid because of your remarks

I put the quotes around fuel because it was the best way to describe it....

Zgringo
Thats not the best way to discribe it...Read what Beef_Bourito says, that best discribes nitrous.

Nitrous doesn't "force" air into the cylinder, it aids in burning the air that's already in the cylinder, it may condense the air and add a little more, but generally, it isn't going to add to the volume in the cylinder.

Zgringo
Nitrous doesn't "force" air into anything, it "forces" nitrous into the intake passage.
Nitrous doesn't aid in burning the air in the cylinder, air doesn't burn.
Nitrous supplys a lot of oxygen to support combustion of the gasoline. Gasoline burns.
Nitrous add a tremendous amount of oxygen to the intake air allowing more fuel to be used and in turn making much more power.

Forced induction is a supercharger or turbo....that's it.

No ram air, nitrous, or anything.....

Zgringo
You better take a course in the english language. If you can truly read, go to the Dictionary and look up the word "FORCE".

Ram air doesn't "force" air into the cylinder, it allows air to pass easier, but by no means is it under pressure at all.

Zgringo
Don't bet any money on your above statement, unless you have money to burn.
Care to learn about ram tuning? Hot Rod Magazine wrote a story about it.

http://www.hotrod.com/projectbuild/113_9907_efi/index.html

I would say that true forced induction is something that converts mechanical or kinetic energy into motion.....and uses the energy to FORCE air under pressure into the engine by use of a turbine
Zgringo
What do you call the "force" of air that moves a sail boat, the "force" of air that turns a windmill that makes electrical power, the hi and low pressure air that "force" a airplane to stay in the air.
What you say is nothing more than than what you say, no facts, nothing. Not even theory. You use the word "force" to your own benifit and anyother use of the word is unacceptable.

Don't criticize my knowledge, correct your ignorance!!

Ram air only works at sufficiently moving speeds. So at idle I'm sitting in my T/A with a Naturally aspirated engine, but gadamn, soon as I'm going down the freeway at 75 mph I have forced induction. I'm not doubting you that ram air is infact FI, just that it's kind of a variable. Now most ram air engines or cars, have it through their hoods, directly into the intake be it carb or port injection. But aren't some ram air engines going to also be limited on their flow? I'm going to say something kind of stupid, but every engine is having air forced into it somehow, because of pressure at sea level, and this changes with elevation. But to me, a forced induction engine is something where air is being FORCED into it, by whatever methods, turbo or super. Now what about when a nitroused engine has it injected into the intake port, it's not really being induced into the engine, it's still being sucked in, not forced, and if it's forced, then by what, the pressure of the bottle?? Because if so, then that bottle, valve and nozzle or w/e is mechanical right there. I really don't know I guess because I just contradicted myself, but either way, it's late, I'm buzzing and I'll leave the hard facts to the guys on this site that know better than me.

Just some things for all of you guru's to think about.... Please read and understand what I have written before responding.
Nitrous Injection...
Nitrous is not being induced directly into the the cylinder. It is sprayed into an open intake tract under 500 lbs of pressure. This pressure does nothing to compress the air in the intake or the cylinder. Have you ever sprayed water out of a hose into a bucket? Same concept... How much "pressure" is in that bucket when you're done spraying? All the pressure does is atomize the nitrous so it is better used by the combustion process. As soon as the nitrous is sprayed the "pressure" drops off to atmospheric and the charge is PULLED into the cylinder by the piston on it's intake stroke. Nothing pushes the charge into the cylinder. This is called Normally Aspirated as there is no mechanical means of pressurizing the intake charge.
Ram Air...
The above concept also applies to the "Ram Air is forced induction" argument. The performance increase you see with a ram air set-up is from the cooler outside (denser) air that is drawn into the aircleaner. Any minor pressure created in the intake by the "RAM" effect, will be immediately drawn off as the piston starts it's intake stroke. There will never be enough "pressure" to force air into the cylinder.
Forced Induction...
Compressing the intake charge to the point of, or greater then, the vacuum created by the cylinder on it's intake stroke to PUSH more air into the cylinder then the piston can physically draw under it's own displacement properties. This requires a mechanical means of compressing the intake charge. A Roots or centrifugal supercharger or a turbocharger are the commonly accepted means of "Forced Induction".
Am I wrong?...

What's this? No more discussion? :disappoin Do I smell bad or something? Is it my breathe? :icon16: Is "school" out for the summer?
Criminy! I didn't expect to shut down the whole thread by simply listing a few points to ponder...
Reading through the thread I can see that most of you guys grasp the principals of forced induction. Some of you don't. If there is anything more to be discussed I'll shut up and listen. :loser: But I want facts here guys; and civil tongues. Brow beating and chest thumping is not going to fly.
To try to get things going again I'll attempt to answer this question which was posed in an earlier reply...
"What do you call the "force" of air that moves a sail boat, the "force" of air that turns a windmill that makes electrical power, the hi and low pressure air that "force" a airplane to stay in the air."
Well, where I come from, we call that "force" WIND. Wind is created when the atmosphere is unbalanced by high and low pressure cells. The atmosphere will try to balance those differences (to the point of stagnation) by exiting a high pressure cell and entering a low pressure one. The "force" created is simply called "wind pressure". This is easily calculated if you are so inclined. Look here: http://instruct1.cit.cornell.edu/courses/arch264/cuhk/courseNotes/wind/wind.html
The real issue though, is the fact that this "force", this "wind pressure", has nothing to do with the care and feeding of a normally aspirated internal combustion engine. What does have direct action on this engine is the "ambient air pressure" the wind is trying to equalize, again, to stagnation. This ambient air pressure is what pushes the intake charge into the cylinder when the piston starts it's intake stroke.
Look at it like this...
Without a mechanical means of maintaining a pressurized intake charge, in a sealed system of course, a N/A engine relies soully on ambient air pressure to push the intake charge into the cylinder. This charge may get an initial boost from ram tuning yes, but, that "boost" is negligible at all but a very narrow RPM band and will quickly equalize itself to ambient before the cylinder fills because there is no pressure to back it up other then ambient air pressure.
Comments? Questions? Anybody?... I'll put my shoes back on. :iceslolan

If you close off two ends of a tube, with a pressure guage at one end, tap in a nitrous line to the other side. Now give it a 50 shot. What does the pressure guage do?

Adding on to what Gringo's sayin up there....
To determine the best length intake runner, you have to do some math. There is a pressure wave that bounces back and forth from the valve to the main chamber in the intake manifold, by way of the runner. This pressure wave travels at the speed of sound. Figure out the length of time between when your valve closes, and when it opens. You have that much time to build a pressure "pocket" behind the intake valve. Of course your runner can't be ~20ft. long, that's why it ricochet's between the valve and the main chamber. I forget the formula, but you can google it. It helped my buddy redesign his intake manifold on his 240, impressive gains felt.

if you take a tube and close off one end instead of both (which is far closer to what you have inside you intake and against your valves) and then you give a 50 shot, what does the pressure do?

If you close off two ends of a tube, with a pressure guage at one end, tap in a nitrous line to the other side. Now give it a 50 shot. What does the pressure guage do?

Adding on to what Gringo's sayin up there....
To determine the best length intake runner, you have to do some math. There is a pressure wave that bounces back and forth from the valve to the main chamber in the intake manifold, by way of the runner. This pressure wave travels at the speed of sound. Figure out the length of time between when your valve closes, and when it opens. You have that much time to build a pressure "pocket" behind the intake valve. Of course your runner can't be ~20ft. long, that's why it ricochet's between the valve and the main chamber. I forget the formula, but you can google it. It helped my buddy redesign his intake manifold on his 240, impressive gains felt.
Lee, This is so far over there head. Your just waisting your time trying to explain. There's a mind set that cant see the forrest, for the trees.
What you've said is very true and only for those willing to learn.
For the rest, let them remain in the dark ages.

this isn't a discussion on intake runner tuning. this is a discussion on forced induction. if you want to consider pressure waves in your intake tract forced induction then every reciprocating car engine is a forced induction motor at some point in its rpm band.

i realize that many people on these forums are here to tell everyone that they are wrong and not listen to anyone, but the majority of the people in this discussion were here to voice their opinions but also hear what other people have to say. i think your being a dick in saying that this is over everyones head. we have had many discussions on this forum about intake and exhaust tuning.

if you take a tube and close off one end instead of both (which is far closer to what you have inside you intake and against your valves) and then you give a 50 shot, what does the pressure do?

Just like water in a bucket, Reed... You are exactly right. There will be no pressure in the tube. As in all normally aspirated engines, the intake is not a tube "sealed" at both ends. It is always open to atmosphere through the carb or injectors. ANY pressure applied to the tube will escape out the "open" end. A supercharger or turbocharger on the other hand ALWAYS works in a SEALED system so the pressure applied can't escape out the open end... This is "forced" induction...
"Please read and understand what I have written before responding."
It looks to me like the above responders didn't even read my previous posts. If they did, they didn't apply the analogies and think about what I had written. If they had they could see there is no scientific basis for believing as they do.
There has been nothing offered on their part to prove their point other then belittlement and name calling. This is not indicative of true knowledge or understanding from my viewpoint. Bullying someone to believe that grass is blue does not make it fact...
As was stated earlier "What you've said is very true and only for those willing to learn." I think this statement swings both ways and you should practice what you preach... This is NOT over anyone's head that will stop and think about the principals and physics involved.
Now, if there is any PROOF to be offered here I am listening... Step up to the plate, keep a civil tongue and PROVE me wrong... Everyone is waiting...

[QUOTE]=Astroracer... Just like water in a bucket, Reed... You are exactly right. There will be no pressure in the tube. As in all normally aspirated engines, the intake is not a tube "sealed" at both ends. It is always open to atmosphere through the carb or injectors. ANY pressure applied to the tube will escape out the "open" end.[QUOTE/]

The problem is it isn't just like water in the bucket. Your statements show just how much you know about physics and ram tuning. Very few engines are ram tuned.
Let's start with the physics part with Newtons law. It says, "Things in motion tend to stay in motion."
Keep that motion pictured in your mind.
Take a 1 1/2-2" tube open on one end and the other end a valve. The valve is open and you have a mass of air going through this tube at the speed of sound. Slam the valve shut and whats going to happen? Well according to Newton and many hi -end tuners, "things in motion tend to stay in motion" the mass of air will continue to stay in motion and start stacking this air in motion against the valve. Now if the tube is the right length that column of air in motion will reach it's maximum pressure just as the valve opens causing a positive pressure on the intake side of the valve. If it's the wrong length, that column of air will have reached it's maximum pressure and start returning the other direction.
Now if 30+hp and 60+ft.lb. torque Isn't considered worth looking into then don't read the following put out by Hot Rod Magazine, but if you'd like to learn more I suggest you read and quit saying it's like pouring water into a bucket.

http://www.hotrod.com/projectbuild/113_9907_efi/

[QUOTE]=Astroracer... Just like water in a bucket, Reed... You are exactly right. There will be no pressure in the tube. As in all normally aspirated engines, the intake is not a tube "sealed" at both ends. It is always open to atmosphere through the carb or injectors. ANY pressure applied to the tube will escape out the "open" end.[QUOTE/]

The problem is it isn't just like water in the bucket. Your statements show just how much you know about physics and ram tuning. Very few engines are ram tuned.
Let's start with the physics part with Newtons law. It says, "Things in motion tend to stay in motion."
Keep that motion pictured in your mind.
Take a 1 1/2-2" tube open on one end and the other end a valve. The valve is open and you have a mass of air going through this tube at the speed of sound. Slam the valve shut and whats going to happen? Well according to Newton and many hi -end tuners, "things in motion tend to stay in motion" the mass of air will continue to stay in motion and start stacking this air in motion against the valve. Now if the tube is the right length that column of air in motion will reach it's maximum pressure just as the valve opens causing a positive pressure on the intake side of the valve. If it's the wrong length, that column of air will have reached it's maximum pressure and start returning the other direction.
Now if 30+hp and 60+ft.lb. torque Isn't considered worth looking into then don't read the following put out by Hot Rod Magazine, but if you'd like to learn more I suggest you read and quit saying it's like pouring water into a bucket.

http://www.hotrod.com/projectbuild/113_9907_efi/

You see Astroracer i've had the privilege in my life of teaching some of the top Indy, dragracing and motorcycle mechanics thing which take you beyond the bolt on mechanic to the true hi-performance tuner.

I understand the basic concepts of ram tuning (i dont pretend to be an expert) and im not saying that these concepts are not associated with forced induction. What i am saying is that nitrous oxide injection does not increase the pressure (possibly a negligeble amount) in the intake of an engine or in the cylinders. I am also saying that while ram tuning will increase the air in a cylinder it does not do so by mechanical means which i still belive is the major requisite for an engine to be considered a forced induction motor.

"Without a mechanical means of maintaining a pressurized intake charge, in a sealed system of course, a N/A engine relies souly on ambient air pressure to push the intake charge into the cylinder. This charge may get an initial boost from ram tuning yes, but, that "boost" is negligible at all but a very narrow RPM band and will quickly equalize itself to ambient before the cylinder fills because there is no pressure to back it up other then ambient air pressure."

The above is from one of my previous posts. As you can see I did agree with the principles of ram tuning but, I also pointed out that the tuning is only effective for a limited RPM range(as was stated in the article...)The motor only runs "well" when it is in this band. And, like you stated, very few engines are ram tuned just for this reason. Ram tuning does provide a performance increase, I agree whole-heartedly, but it is still not "forced" induction. It is a simple manipulation of reversion waves induced during intake cycles and has no means of sustaining itself once the "pressure" is drawn off during the intake stroke of the piston. Once this high pressure "reversion wave" is drawn into the cylinder the rest of the intake charge is relying on ambient air pressure to continue filling the cylinder.
I understand exactly how this works. It is not over my head. Any engine that relies on ambient air pressure for cylinder filling is normally aspirated.
Forced Induction requires a mechanical means of increasing the intake charge pressure above ambient AND sustaining that pressure before, during and after the intake stroke. Ram tuning and Nitrous Oxide cannot do this.

"but if you'd like to learn more I suggest you read and quit saying it's like pouring water into a bucket."
My "water in a bucket" analogy was directed specifically towards the nitrous aspect... Not ram tuning... Ram tuning is a completely different principle and I would never confuse the two...
You really should read my posts through a couple of times before you reply back. You are taking my statements and twisting them to your own "benefit".

When injecting nitrous oxide into the intake tract, are you giving the engine the choice of "ingesting" it? No? Then if the engine isn't taking it in by choice, it must be forced then, correct?

Your turn.

My turn? Does this even deserve a response? I guess I can give one just for the hell of it...
Let me understand what you are saying... You say that, because the engine has no choice but to ingest the nitrous, that it is being "forced" to, correct? So this is the definition of "Forced Induction"?
Any act upon which you "force" an engine to ingest Nitrous Oxide.
Lets think about this...
What about the air and gasoline you are "forcing" the engine to ingest? Every time you step on the throttle you are FORCING gas and air down it's throat... Does it have a choice? No! Is this "Forced Induction" also? According to your theory, yes, it is. So EVERY normally aspirated engine in the world is a forced induction engine. :screwy:
But wait...
What if the engine had a choice? Maybe we should inject urine into the motor along with the nitrous so it could choose what it wanted. Then the motor would not be forced to ingest the nitrous. It could choose between the two and ingest whichever one it likes best. This could be defined as "Freedom Of Choice Induction". I like it!...
Although, as I write this, I have realized the motor already has a choice! It can decide for itself what it wants to ingest between the air, fuel and/or nitrous. It has a choice, sir. This is NOT forced induction. It is "Freedom Of Choice Induction".
I really hope you weren't serious about this... :rolleyes:

Alrighty smart guy. Where does the pressure from a Turbo/Super Charger have the option of going? Where does the N2O have the option of going?

T/S charger CANNOT aid the engine when it is not running. If you spin, by hand or other means, your turbo or super a little, then start the engine, what happens? Same ole start. If you spray some nitrous into the intake then start it, what happens? quite a livelier start wouldn't you say?

I'd say N2O is more forced on the engine than t/c and s/c. You don't decide when to boost, but you decide when to spray.

EDIT: Going on your logic of EVERY-vehicle-being-forced-induction-because-it-doesn't-have-the-option-of-not-taking-the-fuel theory, then a supercharged or turbocharged vehicle is not forced induction because the t/c or s/c is there and a part of the engine and the engine utilizes it no matter what you do with the pedal. If you say you're FORCING more air into the engine with them, you're FORCING more fuel into the engine when you depress the gas pedal. With nitrous, YOU are physically FORCING nitrous into the intake tract for the engine to induct, because THAT is what engines do, they INDUCT whatever is in the air, they INDUCT compressed air, they INDUCT ANYTHING in the intake tract. Putting ANYTHING in the intake tract FORCES the running engine to INDUCT it. Hence, FORCED INDUCTION.

Q)”Alrighty smart guy. Where does the pressure from a Turbo/Super Charger have the option of going? Where does the N2O have the option of going?”
A) An engine under boost will use all of the pressure to fill the cylinders as they open. An overboost situation, where the motor cannot use all of the pressure is controlled with a wastegate in a turbocharged application and a pop-off valve in a supercharged application.
B) Any unused Nitrous will simply vent out the carburetor into the atmosphere or be sucked into an adjacent cylinder. The reason for this is because the intake is not a tube sealed at both ends. It is always open to the atmosphere through the carb or injectors. (Does this sound familiar to anyone?)

Q) ”T/S charger CANNOT aid the engine when it is not running.”
A) Ummm… To my knowledge gasoline and air will not aid an engine when it is not running… What is your point here?

Q) “If you spin, by hand or other means, your turbo or super a little, then start the engine, what happens? Same ole start.”
A) A supercharger is parasitic; it runs off the engine. The motor HAS to be running for the blower to put out boost. You cannot physically spin the blower by hand because it is running through a belt drive hooked directly to the engines pulleys. A turbocharger runs off exhaust gasses, again, the motor HAS to be running for the turbo to build boost. Why would you want to spin them up prior to starting the engine? So you can “force” the engine to start?

Q) “If you spray some nitrous into the intake then start it, what happens? quite a livelier start wouldn't you say?”
A) Yea, I would think so. Probably create a lean misfire and blow the carb off your motor. The engine HAS to be running to use the nitrous shot correctly. Ask anyone who runs nitrous oxide why they don’t start their engine with it. I’d like to be there when you get your answer… Again, why would you want to do this and what is your point?

Q) “I'd say N2O is more forced on the engine than t/c and s/c. You don't decide when to boost, but you decide when to spray.”
A). So, a constant boost pressure of 10psi is not “forced induction” because it is always “there”… filling every cylinder on every intake stroke with 10lbs more pressure then ambient. BUT, because I can decide WHEN to hit the nitrous button that IS “forced induction” because I decided when to “force” the motor to ingest it…
OHH MYY GOD… You’ve got to be kidding, right? Is this your definition of “forced induction”? Jumping up on top of your engine and jamming crap into the carb? Do you have any clue as to what you are saying here? I have a “forced induction” engine because I can “force” it to ingest anything I want…????


EDIT: Going on your logic of EVERY-vehicle-being-forced-induction-because-it-doesn't-have-the-option-of-not-taking-the-fuel theory,
Ah, excuse me! This is YOUR logic from your previous post…
“When injecting nitrous oxide into the intake tract, are you giving the engine the choice of "ingesting" it? No? Then if the engine isn't taking it in by choice, it must be forced then, correct?”
I simply expanded on your statement and defined exactly what you were saying… Don’t twist my words around to say what you want them to say. It doesn’t work.


Q) “then a supercharged or turbocharged vehicle is not forced induction because the t/c or s/c is there and a part of the engine and the engine utilizes it no matter what you do with the pedal. If you say you're FORCING more air into the engine with them, you're FORCING more fuel into the engine when you depress the gas pedal.”
A) Not exactly. You see the pedal simply opens the carburetor to allow more air to be drawn into the engine. The “airflow” over the carburetors’ “venturi” is what actually determines how much fuel is ingested. The engine has a choice here. Do I allow more fuel to pass or do I starve myself to death. We don't “force” more fuel to flow to a correctly operating engine, the airflow through the carb decides this. But we do "force" the accelerator pedal down... Maybe you're right...

Q)”With nitrous, YOU are physically FORCING nitrous into the intake tract for the engine to induct,”
A) Not exactly… That’s what the pressure in the bottle is for. All I do is flip a switch to activate a solenoid or two. Although I do “force” the switch to move so maybe you’re right…

Q) “because THAT is what engines do, they INDUCT whatever is in the air, they INDUCT compressed air, they INDUCT ANYTHING in the intake tract. Putting ANYTHING in the intake tract FORCES the running engine to INDUCT it. Hence, FORCED INDUCTION”
How do you rationalize with an irrational concept like this. You cannot FORCE an engine to do anything… It just does it. It is not a living thing. It is inanimate. It doesn’t CARE what you put in the intake. It has no feeling, no thought.
THIS IS RIDICULOUS. What are we talking about here? A high performance engine modification or just stuffing anything you can into a motor so you can call it "forced induction"?
I can see where you are coming from with this train of thought but it just doesn’t apply to this discussion. Just because you can “force” an engine to ingest crap doesn’t mean it is “forced” into the cylinder. It would still be drawn into the engine under ambient air pressure. Boost pressure greater then ambient is required to fill a cylinder with more air then it can possibly draw in under ambient. This is how a blower or turbocharger works. You can “force” crap into an engine all day long but it will never fill a cylinder beyond it’s capacity at ambient. This is NOT “Forced Induction”. Sorry but I’m not buying it…

[QUOTE=astroracer “If you spin, by hand or other means, your turbo or super a little, then start the engine, what happens? Same ole start.”
[/QUOTE]
I tell you what I'm gonna do, I'm gonna rig up a lawn mower pull starter to be turbo. And when the engine is off, I'm gonna pull on the handle real hard, hop into the drivers seat, switch on, pop the throttle butterfly open, and let the pressurised air spin the engine around till it starts.
Not baaaad, huh?
Saves on the battery!
Wait...
Uhhhhhhhhh..
Oh.

[QUOTE=astroracer “If you spin, by hand or other means, your turbo or super a little, then start the engine, what happens? Same ole start.”
I tell you what I'm gonna do, I'm gonna rig up a lawn mower pull starter to be turbo. And when the engine is off, I'm gonna pull on the handle real hard, hop into the drivers seat, switch on, pop the throttle butterfly open, and let the pressurised air spin the engine around till it starts.
Not baaaad, huh?
Saves on the battery!
Wait...
Uhhhhhhhhh..
Oh.[/QUOTE]


Just to clarify things here... This is JET LEE's statement. Not mine. Any italized phrases in my previous post were his statements. Don't confuse the issue any further with mis-quotes.

Im a new guy and came here to learn something and this is what I see.
I hope all threads aren't like this.

yes, they are, big ego's working against reason.

Boost pressure greater then ambient is required to fill a cylinder with more air then it can possibly draw in under ambient. This is how a blower or turbocharger works. You can “force” crap into an engine all day long but it will never fill a cylinder beyond it’s capacity at ambient. This is NOT “Forced Induction”. Sorry but I’m not buying it…

Ok, now this is what Gringo an I were talkin about. You CAN force pressurized air into the engine without a turbo or super charger. It's called harmonic tuning. It uses pressure waves that travel at the speed of sound to get a pressure pocket built up and moving toward the intake valve. You want this pocket to reach the valve about 5º-10º AFTER the valve starts to open.

Harmonic Tuning.....it forces pressurized air into the cylinders.

i hope you know the speed of sound isn't constant, explain to me how you would tune an intake to work perfectly on different days with different temperatures, humidity factors, and pressure. also, when you inject nitrous into the intake you are ot forcing the nitrous to be injested, you are simply allowing the engine to injest it (which it will) and by doing so you are forcing more oxygen into the cylender by creating this oxygen rich environment.

Ok, now this is what Gringo an I were talkin about. You CAN force pressurized air into the engine without a turbo or super charger. It's called harmonic tuning. It uses pressure waves that travel at the speed of sound to get a pressure pocket built up and moving toward the intake valve. You want this pocket to reach the valve about 5º-10º AFTER the valve starts to open.

Harmonic Tuning.....it forces pressurized air into the cylinders.

Yes, I have agreed with this principal twice before... Here are my two previous posts on the matter. Read them this time...
"Without a mechanical means of maintaining a pressurized intake charge, in a sealed system of course, a N/A engine relies souly on ambient air pressure to push the intake charge into the cylinder. This charge may get an initial boost from ram tuning yes, but, that "boost" is negligible at all but a very narrow RPM band and will quickly equalize itself to ambient before the cylinder fills because there is no pressure to back it up other then ambient air pressure."

The above is from one of my previous posts. As you can see I did agree with the principles of ram tuning but, I also pointed out that the tuning is only effective for a limited RPM range(as was stated in the article...)The motor only runs "well" when it is in this band. And, like you stated, very few engines are ram tuned just for this reason. Ram tuning does provide a performance increase, I agree whole-heartedly, but it is still not "forced" induction. It is a simple manipulation of reversion waves induced during intake cycles and has no means of sustaining itself once the "pressure" is drawn off during the intake stroke of the piston. Once this high pressure "reversion wave" is drawn into the cylinder the rest of the intake charge is relying on ambient air pressure to continue filling the cylinder. This is NOT "Forced Induction".

All I am doing is repeating myself over and over and this is getting stupid and boring. It seems the definition of forced induction can be whatever you want it to be regardless of any applicable laws of physics or reasoning. Define it however you want, I really don't care. I am comfortable with my knowledge and understanding of the subject so I will leave you guru's to your own devices. Have fun. :rolleyes:

i hope you know the speed of sound isn't constant, explain to me how you would tune an intake to work perfectly on different days with different temperatures, humidity factors, and pressure. also, when you inject nitrous into the intake you are ot forcing the nitrous to be injested, you are simply allowing the engine to injest it (which it will) and by doing so you are forcing more oxygen into the cylender by creating this oxygen rich environment.
(bold part) Thank you :smokin:

The speed of sound is not constant, you are right. That's why you tune it so it is right before the valve opens. So on really humid days when sound moves faster, the pressure wave hasn't already bounced off, then on really dry days, the pressure wave is only slightly delayed. You also have to start the equation with the speed of sound related to your particular altitude and average pressure patterns for optimum performance. However, the changes in pressure/humidity/temperature and such are so minute, that the effective rpm range might change by a whole 50rpms, so small you you will not notice it one bit.



All I am doing is repeating myself over and over and this is getting stupid and boring. It seems the definition of forced induction can be whatever you want it to be regardless of any applicable laws of physics or reasoning. Define it however you want, I really don't care. I am comfortable with my knowledge and understanding of the subject so I will leave you guru's to your own devices. Have fun.
I coulda told you that much.

Im a new guy and came here to learn something and this is what I see.
I hope all threads aren't like this.
Yes, it's a bit like trying to answer the question of - *how many angels can dance on the head of a pin*. (It's pointless (sic))
Seems like tempers are flaring up, and nobody has the courage to just stop and let the other guy have the last word. Typical internet argument. Blah, blah, blah.
Hope I quoted the right guy, like it matters....

Me again, and what a great debate!

I think its fair to say that Nitrous (call it "Nitrous") and T / SC (call it "Forced Induction") both provide the combustion process with an oxygen rich environment. This in conjunction with more fuel provides a bigger bang than would otherwise happen.

Its a pity there is not a common term for this process, I was hoping, beyond hope it seems, this could be called "Forced Induction". Seeing as this is not the case would anybody care to invent a new term for it ?

Engine-Ade!!! Like Gatorade, but for the engine!



I don't have a fucking clue.

Me again, and what a great debate!

I think its fair to say that Nitrous (call it "Nitrous") and T / SC (call it "Forced Induction") both provide the combustion process with an oxygen rich environment. This in conjunction with more fuel provides a bigger bang than would otherwise happen.

Its a pity there is not a common term for this process, I was hoping, beyond hope it seems, this could be called "Forced Induction". Seeing as this is not the case would anybody care to invent a new term for it ?


I did. Power adder.

With turbochargers and many newer superchargers, you do have the option of when to boost and when not to. Turbo sizing and throttle position. Key is knowing what you want. I ride past 5500rpm off boost on occasion. Did it today. But I can have full boost at 4k if I choose. I like boost late.