SCT Pro Rave Live Link help...
- Thread starter unity
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unity
Dedicated LVC Member
Been doing some reading on Intake Manifold Volume. That setting is more important that I even figured before. I changed mine from 11 to 4, never went that low. Stock tune is 6. For a NA mostly stock setup, the lower the better. Between 4 and 6 somewhere is ideal usually. Since I dropped to 4 my idle has glassed over and WOT is a new game. I am going to get another data log and see what looks different.
as I said, Manifold Volume is critical, it's used in many different PCM functions.
Also, it's critical that MV be correct and accurate, you dont change manifold volume to a number that makes your car "run right"..you make your car run right with an accurate Manifold Volume number.
Tranisent fuel and overall fueling in general are controlled and affected by MV.
If your overall fueling is correct, and your transient fueling is correct..then your car should run right with the correct manifold volume.
if changing your MV to an incorrect number makes it run better, then.. you've overlooked something.. or changed something to a value that is incorrect.
making "minor" changes to MV is acceptable to correct idle or transient fuel issues..but.. making a 50% change in MV is way outside the margin of a "minor MV change".
your MV needs to represent the REAL MV.
Also, it's critical that MV be correct and accurate, you dont change manifold volume to a number that makes your car "run right"..you make your car run right with an accurate Manifold Volume number.
Tranisent fuel and overall fueling in general are controlled and affected by MV.
If your overall fueling is correct, and your transient fueling is correct..then your car should run right with the correct manifold volume.
if changing your MV to an incorrect number makes it run better, then.. you've overlooked something.. or changed something to a value that is incorrect.
making "minor" changes to MV is acceptable to correct idle or transient fuel issues..but.. making a 50% change in MV is way outside the margin of a "minor MV change".
your MV needs to represent the REAL MV.
Free your Mind.....
Manifold Volume tells the PCM how long it takes for the air that the MAF is reading to actually reach the cylinder.
If Manifold Volume is incorrect..then the PCM doesnt know WHEN the air it measured in the MAF actually reached the cylinder.
If your MV is 11, then the PCM knows that the engine has to ingest 11 liters of air before the mass of air measured by the MAF gets into the cylinder.
If you have that value at 4...then the PCM is making adjustments after ingesting 4 liters of air..rather than 11 when the actual air charge in question.. hits the hole.
Do you have headers as well?
IF so.. the 02's aren't in the correct location either, and that can/will upset the PCM because of the whole "how far away they are" which is a similar issue as what is caused by incorrect MV.
now I wonder {if you have headers) if ALL/MOST of your issue is the transport delay for the 02 sensors..
Manifold Volume tells the PCM how long it takes for the air that the MAF is reading to actually reach the cylinder.
If Manifold Volume is incorrect..then the PCM doesnt know WHEN the air it measured in the MAF actually reached the cylinder.
If your MV is 11, then the PCM knows that the engine has to ingest 11 liters of air before the mass of air measured by the MAF gets into the cylinder.
If you have that value at 4...then the PCM is making adjustments after ingesting 4 liters of air..rather than 11 when the actual air charge in question.. hits the hole.
Do you have headers as well?
IF so.. the 02's aren't in the correct location either, and that can/will upset the PCM because of the whole "how far away they are" which is a similar issue as what is caused by incorrect MV.
now I wonder {if you have headers) if ALL/MOST of your issue is the transport delay for the 02 sensors..
Try a STOCK/Correct MV for your actual Manifold... if it's an aviator.. use the aviator value.. not cobra or mach 1.
Then try increasing your 02 transport delay and see if that has ANY effect on what your dealing with.
Then try increasing your 02 transport delay and see if that has ANY effect on what your dealing with.
you really REALLY need to get WB02..a good solid trustable unit.
now is not the time to try and "DIY build" a WB02.
Fork over the cash and get a good quality unit.
it will be cheaper than your first engine failure which WILL occur if you continue down this path of "change it and see what happens" approach to tuning.
You dont have any accurate data to base your changes from, your missing the primary and most important aspect.. A/F.
Sure you can log STFT and LTFT and get in the ball park, but wont ever get his hodgepodge package to run right without accurate and dependable data.
If your changing MV by 20-40+% to make things work/act right.. your gonna melt something bro...seriously.
you need to fall back, regroup and go down the right path.
you've learned alot..up to this point.
NOW.. go back to square 1.. put a WB02 on the car and TUNE it.
On a stock or semi stock motor your method would work fine
I think your combo is outside the "hunt peck and see" tuning method.
now is not the time to try and "DIY build" a WB02.
Fork over the cash and get a good quality unit.
it will be cheaper than your first engine failure which WILL occur if you continue down this path of "change it and see what happens" approach to tuning.
You dont have any accurate data to base your changes from, your missing the primary and most important aspect.. A/F.
Sure you can log STFT and LTFT and get in the ball park, but wont ever get his hodgepodge package to run right without accurate and dependable data.
If your changing MV by 20-40+% to make things work/act right.. your gonna melt something bro...seriously.
you need to fall back, regroup and go down the right path.
you've learned alot..up to this point.
NOW.. go back to square 1.. put a WB02 on the car and TUNE it.
On a stock or semi stock motor your method would work fine
I think your combo is outside the "hunt peck and see" tuning method.
unity
Dedicated LVC Member
MV is not real volume according to all those on the SCT forum. It not actual liter or size of intake per say. Many are running it around 4.75 which is where I am going next. I realize what you are saying though, but 11 was on the very wrong end of things - but is where it "should" be at for a Mach intake.
I know I need to get a wideband. But I may not even have this car in a Month anyway.
I know I need to get a wideband. But I may not even have this car in a Month anyway.
shoot me some links to that..
Depends on "who" you are listening too....
as I said.. changing manifold volume to an incorrect number COULD make things SEEM better..but.. it's WRONG.
From the PRP description - Manifold Volume (Liters)
Description: this is the volume of the intake manifold in LITERS. this is used as a part of an accelerator pump logic in the newer cars
There is usually little reason to change this value
^those words were typed by a VERY trusted person on the ford tuning industry that is SO well known that he's referred to by a Single LETTER.
I'd trust "Mr Single Letters" Words over ANY SCT tech, or person posting on the SCT proracer forum.
Ok I took a minute or two to look at your datalog, even though it wasn't what I asked for..lolz (kidney punch)
BUT... it does give me some Eye opening information.
open that datalog...
Then read and absorb THIS.
"What do you do with the trim data and MAF data that you have recorded? Start by
looking for a trend in the data. Are the trims positive or negative? Do they stay stable
across your recorded rpm points? Most cars that we have done tend to follow the
following pattern: (idle is a touch too rich and cruise is either OK or too rich). Follow the
trims. They will tell you how far off your MAF curve is - a pretty common and
acceptable variance is +-5%. Can a +-5% trim variance be improved upon? Yes - but
remember that for the OEM +- 4% is generally acceptable. OK so we have data from
Short/Long Term Trims recorded at idle, 1500, 2000, 2500, 3000rpm. (We also
remember that if Long Term is -20 and Short Term is -5 your total 02 sensor trim is -25%
(long term + Short term= total trim). We also have MAF A/D counts or Voltage for the
same points, along with Load. You are now armed with information that will allow you
to start tuning the vehicle beyond our Base Values files.
*** Remember that 02 sensor trims can be fooled by bad sensors (excessive fuel and or
coolant contamination) or they can be fooled by exhaust leaks. (even a small leak the size
of a pencil lead can throw a 02 trim off 3-5%). Also you would like for your trims to be
within a few percent of each other (if Short Term Trim Bank 1 is +-3% you would like to
see Short Term Trim Bank 2 at either the same values or +-2%)"
Then...tell me what your datalog tells you, in regards to the above paragraph and how that relates to what I was telling you about.. "doing it wrong".
BUT... it does give me some Eye opening information.
open that datalog...
Then read and absorb THIS.
"What do you do with the trim data and MAF data that you have recorded? Start by
looking for a trend in the data. Are the trims positive or negative? Do they stay stable
across your recorded rpm points? Most cars that we have done tend to follow the
following pattern: (idle is a touch too rich and cruise is either OK or too rich). Follow the
trims. They will tell you how far off your MAF curve is - a pretty common and
acceptable variance is +-5%. Can a +-5% trim variance be improved upon? Yes - but
remember that for the OEM +- 4% is generally acceptable. OK so we have data from
Short/Long Term Trims recorded at idle, 1500, 2000, 2500, 3000rpm. (We also
remember that if Long Term is -20 and Short Term is -5 your total 02 sensor trim is -25%
(long term + Short term= total trim). We also have MAF A/D counts or Voltage for the
same points, along with Load. You are now armed with information that will allow you
to start tuning the vehicle beyond our Base Values files.
*** Remember that 02 sensor trims can be fooled by bad sensors (excessive fuel and or
coolant contamination) or they can be fooled by exhaust leaks. (even a small leak the size
of a pencil lead can throw a 02 trim off 3-5%). Also you would like for your trims to be
within a few percent of each other (if Short Term Trim Bank 1 is +-3% you would like to
see Short Term Trim Bank 2 at either the same values or +-2%)"
Then...tell me what your datalog tells you, in regards to the above paragraph and how that relates to what I was telling you about.. "doing it wrong".
This is your typical reply when you get asked to "do something you dont want to do".
If your not gonna have the car in a month.. WHY even bother with any of this??
If it isn't worth your time to do it correctly it DAMNED sure aint worth mine time to glean over a 9 megabyte datalog!
Oddboy over on the SCT board looks like he's ready and willing to pick up the babyfood spoon though...good luck.
unity
Dedicated LVC Member
http://www.sctflash.com/forum/showthread.php?t=3871&highlight=intake+volume
And there is a thread link in there too that is a good read.
And there is a thread link in there too that is a good read.
unity
Dedicated LVC Member
Because I am going chapter 7 maybe... ok? I want to work on the car, it keeps me sane. But I just want a great daily drive, not a strip car!
And that was good info. I do in fact have an exhaust leak pre-O2! It small, but I know its there. I can hear it.
unity
Dedicated LVC Member
The ONLY tunes I have are from you. I learn best by comparing then figuring out why certain values are chosen. You have been a huge help of course, but only one source of input is considered dangerous. I just wanted another file that I can compare and thus learn from. I am not going to install that tune he spoon feeds me.
Unity... read this post.. and absorb what he said.
http://www.sctflash.com/forum/showpost.php?p=20889&postcount=30
NONE of that thread applies to you
http://www.sctflash.com/forum/showpost.php?p=20889&postcount=30
NONE of that thread applies to you
I see your chapter 7 and raise you with a section 8...
^^^^^ yea your fuel trims both long and short.. look fubar.
not just one side, either.. both are screwy STFT and LTFT both sides.
I've got a datalog at home, I'll email it to you later this evening unless I get too "safe" and forget...
but it should give you an idea what good STFT and LTFT look like.
my datalog wont be 9 damned megs either..LMAO
P.S. did you know you can open the .csv file in Excel and edit out all the extraneous crap..HINT
not just one side, either.. both are screwy STFT and LTFT both sides.
I've got a datalog at home, I'll email it to you later this evening unless I get too "safe" and forget...
but it should give you an idea what good STFT and LTFT look like.
my datalog wont be 9 damned megs either..LMAO
P.S. did you know you can open the .csv file in Excel and edit out all the extraneous crap..HINT
unity
Dedicated LVC Member
Ya I did. And thats what I learned. Going up in value for a stock NA is not ideal, going down is unless its an aggressive NA setup. 11 is on the higher-ish side of things. I am stock for stock.
See what you need to realize is.. most of those guys are guessing...
OR changing MV because they have fubar'd fueling in some other area and are bandaiding the issue.
those forums are helpful, but can also be harmful because there isn't ANYONE over there that's an Authority on ANYTHING ever since that "single letter guy" left.
he even posted in one of those threads..lolz
unity
Dedicated LVC Member
Anyway, I did some work today on it. Not much. I created a new tune from scratch, changed the baseline items like EGR, AIR, etc.
I then loaded your trans value files since they pretty much rock and stock would make me put a fork in both eyes... twice...
Then I did as one suggested and loaded the Ford Racing 24# injector file (which I never saw before). So everything else, fuel tables, was stock. The car started but missed on high warm up idle, then pretty much wanted to die when it idled down. I then removed the values and the car was fine, so I added the regular 24# value file, and all was good again. So not sure what that was about, but I still smell fuel from that... I started it at WOT after that to clear any fumes in the plenum.
Anyway. So now I have a base file with basic parameters "fixed" for my particular setup. Loaded the injector file and will go from here now with fuel tables and such.
On odd thing is that right now if I tap the peddle at idle the car rocks like my 73 used to. But there is no delay in response of the throttle. Odd, there must be a slight delay or hesitation in something...
I then loaded your trans value files since they pretty much rock and stock would make me put a fork in both eyes... twice...
Then I did as one suggested and loaded the Ford Racing 24# injector file (which I never saw before). So everything else, fuel tables, was stock. The car started but missed on high warm up idle, then pretty much wanted to die when it idled down. I then removed the values and the car was fine, so I added the regular 24# value file, and all was good again. So not sure what that was about, but I still smell fuel from that... I started it at WOT after that to clear any fumes in the plenum.
Anyway. So now I have a base file with basic parameters "fixed" for my particular setup. Loaded the injector file and will go from here now with fuel tables and such.
On odd thing is that right now if I tap the peddle at idle the car rocks like my 73 used to. But there is no delay in response of the throttle. Odd, there must be a slight delay or hesitation in something...
baby steps...take it slow and easy
change very little at a time
i drive my tunes for weeks before making changes..
i know your trying to nail an issue but still give the tune some decent evaluation time unless its horribly wrong from the start.
i know..not much help here
change very little at a time
i drive my tunes for weeks before making changes..
i know your trying to nail an issue but still give the tune some decent evaluation time unless its horribly wrong from the start.
i know..not much help here
starting from scratch from time to time is good.
I've found that a fresh start, does away with alot of issues that are self inflicted.
I've self inflicted my share of issues, believe me.
I have always been trying different things, and many times these things have "no effect" or no effect in the area that I'm paying attention to, or the issue at hand.
but that doesnt mean those changes aren't effecting other things.
more often than not, those changes will not play well with an upcoming change that should have a specific effect..and when the unexpected occurs.. you just have to fall back, regroup and many times, start from scratch.
I just recently started over, and a strange thing occured.
my car went into "open loop" at WOT, which is it supposed to do..but someplace, some how I had changed something that prevented open loop from occuring
So, as you see.. sometimes your changes affect other stuff and it's not until much later that you realize this.
again, sorry.. I know not much help post #2
I've found that a fresh start, does away with alot of issues that are self inflicted.
I've self inflicted my share of issues, believe me.
I have always been trying different things, and many times these things have "no effect" or no effect in the area that I'm paying attention to, or the issue at hand.
but that doesnt mean those changes aren't effecting other things.
more often than not, those changes will not play well with an upcoming change that should have a specific effect..and when the unexpected occurs.. you just have to fall back, regroup and many times, start from scratch.
I just recently started over, and a strange thing occured.
my car went into "open loop" at WOT, which is it supposed to do..but someplace, some how I had changed something that prevented open loop from occuring
So, as you see.. sometimes your changes affect other stuff and it's not until much later that you realize this.
again, sorry.. I know not much help post #2