o2 vs egt debate

[Apexi99]

"an egt WILL NOT tell you if you are running rich or lean. it measures exhaust gas temperature ONLY. from there you need to gather other info like fuel pressure and current A/F ratio thru a wideband or your own STOCK O2 SENSOR to determine if the hotter temps indicate a ""lean condition "" OR more importantly a restrictive turbo and/or exhaust system. there is alot more to it than saying hey i am running 1500 degrees let me increase fuel thru the injectors.. it may make it worse.!!"

"EGT readings WILL NOT give you a proper A/F ratio. NO MATTER WHAT.
there is no need to get into it about false lean readings and such. plain and simple it is only a measurement of EXHAUST TEMP WHICH WILL GIVE YOU A RELATIVE UNDERSTANDING OF GAS VELOCITY. there is no magic number or chart to look up and say at this temp i am at 12:1.
its a fanatsy. you can only infer with the readings and use OTHER helpful info to determine the efficiancy and validity of those temps. every car , every exhaust , every induction, injection, ignition on every car is different at EVERY COMBUSTION CYCLE. it is impossible to use it as a reference for the proper A/F ratio"


this was quoted from another board...some of it doesnt sound right to me..at all...can some of you guys give your thoughts on it

 

[brads]

EGTs don't tell you what the mixture is like, they tell you what temp the exhaust gasses are at the EGT probe. There are a number of things that can influence the EGTs, besides the air fuel ratio. Among them are cam timing, overlap, and ignition timing. Ignition timing is a very big one. Your EGTs will go way up when your timing is retarded, because the combustion occurs later, and the gasses don't have as much time to finish combustion and cool before they pass by the EGT probe. If you get a good bit of advance, and no knock retard, then your EGTs go down. This is because the exhaust has more time to finish the combustion and cool before the exhaust valves open, and the gases go by the EGT probe.

Don't rely on your EGT probe to try to figure out what the engine is doing. You need more info than it provides. I have an EGT gauge, but don't use it to tune, its more or less just a warning to tell me something isnt quite right, and that I need to check how the car is running.
Here's another thread discussing EGTs, look at the posts by 95GSXRacer, he knows what he is talking about.

http://www.dsmtuners.com/forums/showthread.php?s=&threadid=41270&highlight=egt

The O2 sensor also changes its output with respect to exhaust heat, so you might not want to rely on it too heavily either.

Brad

 

[igs]

That guy doesn't know what he's talking about.

Why do I need an Exhaust Gas Temperature Gauge?

A leaner mixture will give you more power by making more heat. Too much heat, and things start to melt. You need to find out what's going on inside the motor before it's too late. Your car will never feel so fast as when the pistons are just beginning to melt. Most people who install an EGT are amazed at how close to the edge they are running. This is a must if you are going to experiment.

http://www.roadraceengineering.com/eclgages.htm

 

[NICKYTALON]

I FELL THE BASE WAY TO TUNE after 6 years of trying myself is to tune for zero knock and maximum timing, egt o2 volts are a waste of time in my opinion timing makes power look for 18-20 deg and no knock

 

[brads]

IGS, you are a moron. I tried to be nice, and not post how moronic you are on the other thread. It seemed obvious. Too bad you are too moronic to get how obvious it is. Mike and the other guys at RRE are smart. Why don't you forward your other comments to them, and they will tell you how moronic you are as well.

The statements on the RRE website are made simple because they know that village idiots like you are the ones who read the stuff. When tuning with an AFC, their recommendations about going for more EGT make sense. You need to lean out your bigger injectors, and doing so gets you more timing. It becomes a balancing act between AF ratio and timing. The RRE method of approaching this works very well with an afc or similar device.

Leaner mixtures do increase EGTs, up to a point, then leaner mixtures = lower EGTs. This is on a engine with fixed timing, where there is no knock detection, or anything else affecting it. Unfortunately, these numbers are going to vary alot between engines based on many things, as mentioned in the first post, and as I pointed out. So if you have the ability to fine tune everything, using EGTs to tune with isnt the best way to get tuned. It's better than nothing, and will get you tuned in the right ballpark with an AFC.

Go get a book on engine management. Don't try to learn how this stuff works by picking up snippets from various shops websites, you will never have a good understanding of it. And ripping on people who have actual experience with the subject, like you did with 95GSXRacer, based on some info you picked up off of a shops website makes you look even dumber. Its a good thing you didnt explain that THAT was your "expertise" and was why you were disagreeing with Kevin in the other thread, you would have been mocked badly.

Brad

Originally posted by igs
That guy doesn't know what he's talking about.

Why do I need an Exhaust Gas Temperature Gauge?

A leaner mixture will give you more power by making more heat. Too much heat, and things start to melt. You need to find out what's going on inside the motor before it's too late. Your car will never feel so fast as when the pistons are just beginning to melt. Most people who install an EGT are amazed at how close to the edge they are running. This is a must if you are going to experiment.

http://www.roadraceengineering.com/eclgages.htm

 

[brads]

Yep, similar numbers work for good for me. O2 starts falling off even with a steady mixture, just from the heat of the exhaust gases affecting the O2 sensors output.

Brad

Originally posted by NICKYTALON
I FELL THE BASE WAY TO TUNE after 6 years of trying myself is to tune for zero knock and maximum timing, egt o2 volts are a waste of time in my opinion timing makes power look for 18-20 deg and no knock

 

[igs]

Originally posted by brads
IGS, you are a moron. I tried to be nice, and not post how moronic you are on the other thread. It seemed obvious. Too bad you are too moronic to get how obvious it is. Mike and the other guys at RRE are smart. Why don't you forward your other comments to them, and they will tell you how moronic you are as well.

Oh so now you want to start the personal attacks? Bring it on bi***! Just because you're too stupid to understand even the basics of how an internal combustion engine works you need to resort to name calling. You dumb phuck.

 

[brads]

"Bring it on bi***"? Are you 12? You really shouldnt be offering your opinions on here. I am sorry that you still are too slow to comprehend what I am saying. You have yet to offer ANYTHING useful, to back up what you are saying, or anything correct for that matter. Go learn about engines. And just because you read a paragraph on some shops website about EGTs, don't think that you are now gods gift to tuning.

Brad

Originally posted by igs


Oh so now you want to start the personal attacks? Bring it on bi***! Just because you're too stupid to understand even the basics of how an internal combustion engine works you need to resort to name calling. You dumb phuck.

 

[LandoAWD]

Post reported guys....give it a rest.

 

[kpt4321]

Moderators: We have a major problem here. Now, there is absolutely nothing wrong with less knowledgable people coming to this site in order to learn things, and obviously, everyone is going to be wrong sometimes. There are very experienced people here to "show the light" to the newbies, and we will all learn something.

However, on the other hand, this IGS poses a VERY large problem. These same newbies have a tendency to believe everything they read (not really their fault), and it is thus that misinformation spreads VERY quickly. IGS has been proven wrong several times by several different memebers of this board, and yet still continues to try to convince people that things work in way which they do not.

Please, put an end to this. We're here to spread knowledge and facts, not this false information that belongs on some ricer board.

IGS: You have yet to actually tell us why these people are "morons," you have yet to make any technical arguements for your claims. Do you have any knowledge whatsoever, or do you just call other people morons to boost your self-esteem? If you have technical information, post it. If you don't, then keep your mouth shut.

Now, to the topic of EGT's: It is very true that the A/F ratio of the mixture will effect the temperature of the waste gases. However, the fact of the matter is, in a system such as the stock DSM ECU where there is active timign control, the diference due to A/F ratio is negligible compared to the effects of timing changes.

Check out that thread that "brads" posted, it contains some very useful information on the subject of EGT's.

APexi99, how familiar are you with the nature of an internal combustion engine? If you could give us a little more information about how much you understand, then I'm sure we can clear up the stuff that doesn't make sense. I don't want to assume you don't know something, and then type up a huge explination for it, if you already know how it works. Let me know, and I'll try to clear up the fuzzies.

 

[igs]

Originally posted by kpt4321

IGS: You have yet to actually tell us why these people are "morons,"

Are you illiterate? I didn't call anyone a "moron". brads did all the name calling.

Originally posted by brads
IGS, you are a moron. I tried to be nice, and not post how moronic you are on the other thread. It seemed obvious. Too bad you are too moronic to get how obvious it is. Mike and the other guys at RRE are smart. Why don't you forward your other comments to them, and they will tell you how moronic you are as well.

So it doesn't matter what I post, you children will just say I said something I didn't.

 

[kpt4321]

Originally posted by igs


Are you illiterate? I didn't call anyone a "moron". brads did all the name calling.

My apologies, I had mistaken which childish comments came form which one of you.

I'm not illiterate, just confused.

So it doesn't matter what I post, you children will just say I said something I didn't.

You STILL haven't posted anyway worth reading! You quoted a little piece of text from the RRE page, and that has been the entire extent of your contribution to this discussion!

RRE is right. The A/F mixture does effect EGT. However, LIKE I ALREADY SAID, it has a very veyr small effect compared to the effect of timing. With timing always changing, there is no way you're going to be able to see minute changes in the A/R ratio reflected in the EGT's.

RRE's description is vastly simplified, becuase they are trying to SELL products. Rather than attempt to explain ignition timing to someone who doesn't even know what ignition is, they just simplify it and say "lean = hot." It's easier for them, and easier for the uneducated customers.

If you really need to, e-mail RRE. Ask them if, in a car with active timing control such as a DSM, timing or A/F ratio has a larger effect on EGT's.

When they tell you it's timing, then you'll probably just tell them "Just because you're too stupid to understand even the basics of how an internal combustion engine works you need to resort to name calling. You dumb phuck."

Let me know when you come up with anything besides a little paragraph that you can cut and paste from someone's page.

<edited for formatting>

 

[brads]

Originally posted by kpt4321

My apologies, I had mistaken which childish comments came form which one of you.
[/B]

I would like to respectfully disagree. You are implying that me calling him a moron is a childish comment, and not an accurate assessment of mental capacity. Look at what useful things he has contributed here. And look at his first response to the other EGT thread:

Originally posted by igs

That is one biiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiig pile of horseshit.
[/B]

Now look at the definition of moron:
moron

\Mo"ron\, n. (Pedagogy) A person whose intellectual development proceeds normally up to about the eighth year of age and is then arrested so that there is little or no further development.


He seems to fit the bill. He has zero knowledge of the subject matter, other than what little he has cut and pasted from RREs website, and even with that, he doesnt seem to grasp how it works. He did learn how to say horseshit though. So his intellectual development probably did stop right around age 8.

Brad
PS Feel free to boot me for giving this imbecile a hard time. I don't really care. I am respectful to people on here with honest questions, and more than happy to help where I can. I don't appreciate obnoxious stupid people though, so if pointing out to them what they are is grounds for getting booted, I need to be booted.

 

[kpt4321]

No arguement Brad, I agree with you 100%. I was just a little jumpy becuase of that troll.

I also agree with the second part. I totally do not mind helping newbs, but this guy is all over the place spareding misinformatrion, or spreading nothing at all. Somebody needs to put a stop to it, and since the moderators are too busy banning signatures, Brad and I seem to have gotten stuck with babysitting duty.

 

[LandoAWD]

Mods do more than that

Post reported again. I suggest that even the ones who are "right" drop the insults quickly.

 

[L2RTSiAWD]

Thread closed.

Many People tune many different ways you find which one is right for you.

EGT's and A/F Ratio's both play a part.