Volumetric Efficiency - Page 2

oab_au · #16 06-11-2006, 07:29 PM

Quote:

Originally Posted by Trevor

The ECU obtains a signal from the MAF on the basis of current flowing in the signal line, rather than voltage, which varies as compensating factors adjust and runs 12-14 volts above ground. The current is directly proportional to the mass of air flowing.

Therefore if you were to insert an ammeter in the signal line you should be able to secure a useful proportional measurement, which you could plot. I would guess that only milli amps will be involved. The resistance of a moving coil, or digital instrument, should not effect the signal and in fact will be compensated for.

Another waste of space. You either don't read or comprehend the posts. In SVXrides post above, he states

Quote..The wide band that SVXFiles and Mychailo both have (okay, so I've still got Mychailo's ) both have datalogger features. If you go back and check some of Mychailo's posts, you'll see he was able to measure MAF voltage vs rpm. There really shouldn't be any reason why you can't tap into any of the lines coming out of the ECU (as long as their voltage levels are sufficient).
-Bill

He even tells you that there is more info in Mychailos previous posts. You obversely don't use the Search Button, or you would have found a lot of informative discussion on this very subject, by Longassname, whom I believe would know the subject better than any. Fortunately most people would remember the discussion, and know that the MAF sensor's output is 0V to 5V.

But no, you just post a load of absolute crap, that is going to lead Chuck on a wild goose chase wasting time and effort, and mislead any body in the future who reads this BS.

Harvey.

Trevor · #17 06-11-2006, 08:54 PM

Sorry but we have had a storm which cut the power to much of the city and my post suffered as well as my computer. I have another on line, but not with the latest files. Harvey rest assured I will be back to counter your tantrum.

------- In order to pacify your frugal nature, but having noted your use of space as above, lecturing all those well versed in simple IC engine theory on how to suck eggs by way of your usual diversion, I have edited and will continue without opening another post.

It is interesting that you now accuse me of submitting material which could mislead. A little originality would not go amiss, considering kettles, pots and black.

N.B. In your capacity as an automotive engineer, will you please advise as to whether the SVX MAF has an element which is directly or indirectly heated. As soon as this information is forthcoming from you I will provide my exact informative answer to your rude tirade.

oab_au · #18 06-12-2006, 04:33 PM

Quote:

Originally Posted by Trevor

Sorry but we have had a storm which cut the power to much of the city and my post suffered as well as my computer. I have another on line, but not with the latest files. Harvey rest assured I will be back to counter your tantrum.

------- In order to pacify your frugal nature, but having noted your use of space as above, lecturing all those well versed in simple IC engine theory on how to suck eggs by way of your usual diversion, I have edited and will continue without opening another post.

It is interesting that you now accuse me of submitting material which could mislead. A little originality would not go amiss, considering kettles, pots and black.

N.B. In your capacity as an automotive engineer, will you please advise as to whether the SVX MAF has an element which is directly or indirectly heated. As soon as this information is forthcoming from you I will provide my exact informative answer to your rude tirade.

A storm lost your post?. Not to worry, I still have it on the E-Mail notification, and it shows your lack of knowledge lot better than your second effort. As we can see here:

[/Quote] Trevor has just replied to a thread you have subscribed to entitled - Volumetric Efficiency - in the Technical Q & A forum of The Subaru SVX World Network.

This thread is located at:
http://www.subaru-svx.net/forum/show...8&goto=newpost

Here is the message that has just been posted:
***************

Quote:

Originally Posted by oab_au

Another waste of space. You either don't read or comprehend the posts. In SVXrides post above, he states

Quote..The wide band that SVXFiles and Mychailo both have (okay, so I've still got Mychailo's ) both have datalogger features. If you go back and check some of Mychailo's posts, you'll see he was able to measure MAF voltage vs rpm. There really shouldn't be any reason why you can't tap into any of the lines coming out of the ECU (as long as their voltage levels are sufficient).
-Bill

He even tells you that there is more info in Mychailos previous posts. You obversely don't use the Search Button, or you would have found a lot of informative discussion on this very subject, by Longassname, whom I believe would know the subject better than any. Fortunately most people would remember the discussion, and know that the MAF sensor's output is 0V to 5V.

But no, you just post a load of absolute crap, that is going to lead Chuck on a wild goose chase wasting time and effort, and mislead any body in the future who reads this BS.

Again a tantrum in an effort to support another of your many errors, none of which you have been able to answer or explain. It is clearly you who should be the subject of your comment, "mislead any in the future who reads this BS". Significantly here, once again, you give clear evidence accordingly.

The MAF output signal measured as a VOLTAGE will NOT provide provide readings of any use, as I have pointed out. You are once again WRONG, WRONG, WRONG! What is more from where do you derive what you stupidly state as "0V to 5V".

MAF measurement is achieved by heating with an electric current, a wire/gauze/grid whatever, that is suspended in the engine's air stream. The electrical resistance increases with the wire's temperature, which as a result limits electrical current flowing through the circuit. When air flows past the wire, the wire cools decreasing its resistance. This in turn, allows more current to flow through the circuit. As more current flows, the wire's temperature increases until the resistance again reaches equilibrium.

The amount of CURRENT required to maintain the wire's electrical resistance is directly proportional to the mass of air flowing past the wire.

As a side, interesting issue, if air density increases due to an atmospheric pressure or temperature change, but the moving air volume remains constant, the denser air will conduct more heat from the wire, so that as a result, higher mass airflow will be indicated.

It may be difficult for you to understand from the above, that the voltage of the signal will not vary in line with MAF measurement, as ability is required to appreciate this is part of the compensating feature of the circuit. Using Voltage can NOT be used as a factor in any shape or form in this instance.

Others will have understood that which I previously posted, but I accept that this will continue to be beyond you and your class.
***************

There may be other replies also, but you will not receive any more notifications until you visit the forum again.

Nobody asked 'How the Mass Air Flow sensor works' the question that Chuck and JJ both asked was "What is the best way to log data from the MAF...??" and now, we have your answer.

Harvey.

oab_au · #19 06-13-2006, 07:38 PM

Posting Guidelines, Rules, and Actions:

First and foremost, please treat all members with the same amount of respect you wish to receive. If you do not wish to receive respect, you probably don’t belong here.

Coarse, vulgar, or malicious language is not allowed, and will be censored along with a warning. If it continues, a time out, or suspension will apply.

Flames and baiting members are not acceptable. Posts like these will be deleted and offenders will be warned.

Inflammatory, sexist, and racist comments, as well as those containing strong sexual content, will not be tolerated. They will be deleted immediately and the member will be warned.

The SVX World Network is a “community.” As in all communities, there will be disagreements, however, if we are to peacefully coexist, we ask that disagreements be either worked out in a civil manner, or, members who disagree, agree to disagree. Time and time again, we have been told that “this community” is unlike any other, in that the members seem to be able to get along without bravado and a need for “one-upmanship.” We ask that you respect the traditions of this community that have evolved since the forum’s beginnings in 2001.

Harvey.

immortal_suby · #20 06-13-2006, 07:46 PM

Might I remind everyone of our site rules.
http://www.subaru-svx.net/photos/files/How-To/15892.doc
Please stop the personal attacks. I believe the participants here are wise enough to have a technical discussion that doesn't involve name calling.

Trevor · #21 06-13-2006, 08:04 PM

Quote:

Originally Posted by immortal_suby

Might I remind everyone of our site rules.
http://www.subaru-svx.net/photos/files/How-To/15892.doc
Please stop the personal attacks. I believe the participants here are wise enough to have a technical discussion that doesn't involve name calling.

Why do you not direct your advice towards Harvey, the devious one. A direct reply was called for and I stand by my statements. Honesty is obviously is not a characteristic upheld here.

Sincerely, Trevor

immortal_suby · #22 06-13-2006, 08:08 PM

Quote:

Originally Posted by Trevor

Why do you not direct your advice towards Harvey, the devious one. A direct reply was called for and I stand by my statements. Honesty is obviously is not a characteristic upheld here.

Sincerely, Trevor

Trevor,
I purposely worded my post openly as to not accuse anyone in particular, but since you ask, I see no violation of site rules in Harvey's posting. The post that contained an infraction of the site rules has been removed and the person involved has been contacted via private message.

Trevor · #23 06-13-2006, 08:34 PM

Quote:

Originally Posted by immortal_suby

Trevor,
I purposely worded my post openly as to not accuse anyone in particular, but since you ask, I see no violation of site rules in Harvey's posting. The post that contained an infraction of the site rules has been removed and the person involved has been contacted via private message.

No ! Because he was and is devious, but he DID call me a liar. No comment from you on that score.

You have removed a post which contained valid information upholding my honesty. Why did you not simply delete that which you judge as controvening your rules. In fairness I request that you do so and restore my valid reply to that which was dishonest.

I am not inclined towards dishonesty and I will not again post here in any shape or form due to dishonest bull$hit being recorded as that most important here. However the other dishonest, devious person involved will be happy with you as ally.

Sincerely, Trevor.

immortal_suby · #24 06-13-2006, 08:49 PM

I see no post in this thread where you are called a liar. Obviously you had a power outage but your post was successfully submitted via email subscription before it made it to the network server, so any member subscribed to that thread would have a copy but the network server would have lost it.

As requested - here is the part of your post which contained valid information. The rest of the post being inflammatory will remain deleted:

Quote:

Originally Posted by Trevor

"N.B. (Harvey) In your capacity as an automotive engineer, will you please advise as to whether the SVX MAF has an element which is directly or indirectly heated.
As soon as this information is forthcoming from you I will provide my exact informative answer.....

Now that I do have an answer, obviously obtained from another more reliable source, I am able to acknowledge that although measurements are current related, the SVX instrument converts these to a voltage signal prior to transmission. Therefore I am happy to state without qualification, that my suggestion of taking direct current readings will not work. I WAS WRONG.

immortal_suby · #25 06-13-2006, 08:55 PM

Quote:

Originally Posted by Trevor

I am not inclined towards dishonesty and I will not again post here in any shape or form due to dishonest bull$hit being recorded as that most important here. However the other dishonest, devious person involved will be happy with you as ally.

Sincerely, Trevor.

I am sorry that you see things that way. All of the moderator and admin team here try to be as open minded and fair as possible. There are no alliances. We just try to help everyone to play by the rules. Obviously all those with technical knowledge are warmly welcomed here as we have alot to learn from them. But we will not condone rule infractions by any member whether they are a technical expert or a newbie.

Trevor · #26 06-13-2006, 09:03 PM

[QUOTE=immortal_suby]I am sorry that you see things that way. All of the moderator and admin team here try to be as open minded and fair as possible. There are no alliances. We just try to help everyone to play by the rules. Obviously all those with technical knowledge are warmly welcomed here as we have alot to learn from them. But we will not condone rule infractions by any member whether they are a technical expert or a newbie.[/
QUOTE]

You play to the song of the devious not the honest and I leave you to their music.

ensteele · #27 06-13-2006, 10:06 PM

I think that some of you are taking this much to seriously. It is time to count to 10 and take some time to cool down.

Uncamitzi · #28 06-13-2006, 10:15 PM

I was having a hard time following all that anyway...

what does volumetric mean ...? anyway?

svxistentialist · #29 06-14-2006, 03:48 AM

I'm with Earl as well.

Take a breather and count to ten. Keep it cool.

I see no value, maybe even negative value, in a combative approach to correcting technical replies.

From time to time poor or even bad information gets posted. Usually someone better informed will correct it, a couple of people will offer different views. All of these different views add to the sum total of knowledge and learning about the SVX, which is a pretty complicated car.

If I notice a reply that seems to be wrong, or I am sure it is wrong, I post a reply stating the reasons, but I don't accept there is a reason to berate the person posting the information.

The operative word here is "help". If somebody asks for help, they may get a variety of posts in reply varying from untechnical amateur to professional technician.

It is not against the rules of the forum to offer information that may not be correct. It IS against the rules to castigate someone who has offered such incorrect information.

That's the bottom line here.

Joe

ensteele · #30 06-15-2006, 09:46 PM

Quote:

Originally Posted by Uncamitzi

I was having a hard time following all that anyway...

what does volumetric mean ...? anyway?

Mitch - I think it has something to do with drinking! I hope!

PS Any more movement towards this side of the coast?