MAFLESS VE Tuning
09-19-2004, 11:33 PM
#81
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I disable the LT FT's for Horist and mine. This allows for better cell by cell accuracy using the ST FT's. Also, Horist is in SD mode as well. I'm afraid if he re-enables his MAF, his tune will get all screwed up.
Your engines actual VE table IS smooth. I bet if you smooth out your table by hand a little bit it runs better and is more inline with how it should be.
Set decimal precision to 1, reload the table and hand smooth some of the HUGE peaks you have.. Try to add some natural curve to the graph. Then when you think it is pretty close and semi-smooth, hit the poly button just once.
From then on, only hand smooth the table. No more poly button action.
Edit: Also, when you are smoothing your table, put emphasis on cells that you actually logged fuel trims for. If you logged fuel trims up to say 4K RPM's and it is considerablly different than 4400, chances are the 4K rpm cells are right but the 4400 are not, so modify the 4400 cells more to match up smoothly with the 4K cells.
Don't try to smooth cells you have calculated with smooths you have not. Smooth the ones you have not to match the ones you have.
Your engines actual VE table IS smooth. I bet if you smooth out your table by hand a little bit it runs better and is more inline with how it should be.
Set decimal precision to 1, reload the table and hand smooth some of the HUGE peaks you have.. Try to add some natural curve to the graph. Then when you think it is pretty close and semi-smooth, hit the poly button just once.
From then on, only hand smooth the table. No more poly button action.
Edit: Also, when you are smoothing your table, put emphasis on cells that you actually logged fuel trims for. If you logged fuel trims up to say 4K RPM's and it is considerablly different than 4400, chances are the 4K rpm cells are right but the 4400 are not, so modify the 4400 cells more to match up smoothly with the 4K cells.
Don't try to smooth cells you have calculated with smooths you have not. Smooth the ones you have not to match the ones you have.
Last edited by Magnus; 09-19-2004 at 11:40 PM.
09-20-2004, 07:43 AM
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Thanks for the information very helpful. Looks like i need more seat time and logging.
Quick question how much do you need to push the ve table in order to see a 1% chane in trims. Is it like 4:1 or 1:1 and where would i go to disable the LTFT?
Thanks again
Edit
Another thing i notice is because i am running on the Sec ve table a lot of the cells that are hit while logging are in between data points on that table
Quick question how much do you need to push the ve table in order to see a 1% chane in trims. Is it like 4:1 or 1:1 and where would i go to disable the LTFT?
Thanks again
Edit
Another thing i notice is because i am running on the Sec ve table a lot of the cells that are hit while logging are in between data points on that table
Last edited by HumpinSS; 09-20-2004 at 08:10 AM.
09-20-2004, 08:06 AM
#83
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Originally Posted by GrannySShifting
Part of the benefits of the MAF, is that it does a decent job accounting for weather changes because the density of the air changes. Im sure thats why GM likes to rely on 2 inputs, to reduce error. Remove the MAF, and now you have to fix the error! 
09-20-2004, 09:17 AM
#84
Yes im aware hes runnign it, but he has the benefit of tuning knowledge, all the software to do it, and he has alittle bit of time in it. I talked to him when he first was woking on his speed density stuff, after talking to Aussie guys 2 years ago about doing it, what all needed to be done etc. Probably before you bought your car 
2 years ago I decided I didnt need to go that route, still havent had a combo I couldnt tune with the MAF on it. Im doing a speed density setup in a month or two not because of necessity, but because of packaging issues. Im sure driveability coudl get even more refined with a SD tune on some cars, but without a load dyno your talkign lotsa time, and money for most guys
Magnus car is built to go fast. WOT tuning is the EASIEST stuff to tune, speed desnity would not cause much problem there. Its hitting everywhere and talking the MAF out of the loop not helping to account for the weather that adds the work. Remeber two days ago when you said your car was acting like a carburetor car? Ask Keith what took more time, WOT, or everythign under it
Its not SD sux, its that its something else to do - thats what I said. I ran in SD two years ago on a car. Time wasnt justifiable, car didnt need it, just wanted to learn what functions when the MAF is dropped out of the loop. This is before LS1 Tech and Hp tuner and the aussie guys got on here and started pointing people the right way. I think its good that you are trying diffferent stuff to work out your problem
2 years ago I decided I didnt need to go that route, still havent had a combo I couldnt tune with the MAF on it. Im doing a speed density setup in a month or two not because of necessity, but because of packaging issues. Im sure driveability coudl get even more refined with a SD tune on some cars, but without a load dyno your talkign lotsa time, and money for most guysMagnus car is built to go fast. WOT tuning is the EASIEST stuff to tune, speed desnity would not cause much problem there. Its hitting everywhere and talking the MAF out of the loop not helping to account for the weather that adds the work. Remeber two days ago when you said your car was acting like a carburetor car? Ask Keith what took more time, WOT, or everythign under it
Its not SD sux, its that its something else to do - thats what I said. I ran in SD two years ago on a car. Time wasnt justifiable, car didnt need it, just wanted to learn what functions when the MAF is dropped out of the loop. This is before LS1 Tech and Hp tuner and the aussie guys got on here and started pointing people the right way. I think its good that you are trying diffferent stuff to work out your problem
09-20-2004, 09:26 AM
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Yeah they are functioning. I watch them closely while i am tuning. Keith also help horist tune his car on the street. So both of their cars benifit from the SD tune. It doenst really take all that time just some logging under normal driving conditions and the histograms (whichwe didnt have two years ago) spells everthing out for you
BTW I have had my car for 4 yrs now
:y
BTW I have had my car for 4 yrs now
:y
09-20-2004, 07:16 PM
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well, we spent 5 hours or so on Mikes tune to get it dialed in close to what it should be.
I think its easier to tune SD just takes a lot more time. I am not very happy with how unreliable and inconsistant the MAF can be at times. On Mikes (Horist) car, this MAF had VERY large spikes over 6000 RPM's. It looked like a mountain range. Certainly in MAF mode that can't be good for consistant fueling.
And ya, street tuning is where much of the time in SD takes place. WOT is fairly easy. First you dial in your WOT VE, then you just play with the PE.
One thing that I think is more critical in SD than in MAF mode is accurate IAT readings. If your IAT gets saturated from a stop light or staging lanes, it does not respond to the fresh air as fast as the MAF does and thus your air/fuel will be off.
I will be relocating my IAT someplace away from any heat soaked area.
Disabling the LT's is not in 1.4 release.
if I see +10 on LT's, I will adjust those cells by 8% and then smooth surround cells to match.
Now that my VE table is very smooth, if I see an area of cells that are all -1 and then a cell in the middle that reads +8, I will not change anything. I consider that fluke data. If I did raise the VE table for that particular cell and then smooth the surroundign cells, chances are they would be -4 or so the next time around.
I think its easier to tune SD just takes a lot more time. I am not very happy with how unreliable and inconsistant the MAF can be at times. On Mikes (Horist) car, this MAF had VERY large spikes over 6000 RPM's. It looked like a mountain range. Certainly in MAF mode that can't be good for consistant fueling.
And ya, street tuning is where much of the time in SD takes place. WOT is fairly easy. First you dial in your WOT VE, then you just play with the PE.
One thing that I think is more critical in SD than in MAF mode is accurate IAT readings. If your IAT gets saturated from a stop light or staging lanes, it does not respond to the fresh air as fast as the MAF does and thus your air/fuel will be off.
I will be relocating my IAT someplace away from any heat soaked area.
Disabling the LT's is not in 1.4 release.
if I see +10 on LT's, I will adjust those cells by 8% and then smooth surround cells to match.
Now that my VE table is very smooth, if I see an area of cells that are all -1 and then a cell in the middle that reads +8, I will not change anything. I consider that fluke data. If I did raise the VE table for that particular cell and then smooth the surroundign cells, chances are they would be -4 or so the next time around.
09-20-2004, 08:11 PM
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The 85mm MAFs have the thermistor in the throat
and you might want to do the same; what's bad is
having it in some "backwater" location that sees
little flow. Punch it through your bellows & goop
it up, etc.
I see a fair bit of frequency noise on MAFs just
running them on a vacuum blower. But I bet the
frequency spikes could be from engine voltage
drops (like I see my headlights dim every once
in a while) and that would make the MAF throw
more pulses to hold heat. I wonder whether
there's any benefit to making a nicely filtered,
even regulated supply for the MAF.
and you might want to do the same; what's bad is
having it in some "backwater" location that sees
little flow. Punch it through your bellows & goop
it up, etc.
I see a fair bit of frequency noise on MAFs just
running them on a vacuum blower. But I bet the
frequency spikes could be from engine voltage
drops (like I see my headlights dim every once
in a while) and that would make the MAF throw
more pulses to hold heat. I wonder whether
there's any benefit to making a nicely filtered,
even regulated supply for the MAF.
09-22-2004, 06:39 PM
#91
Originally Posted by GrannySShifting
Yes im aware hes runnign it, but he has the benefit of tuning knowledge, all the software to do it, and he has alittle bit of time in it. I talked to him when he first was woking on his speed density stuff, after talking to Aussie guys 2 years ago about doing it, what all needed to be done etc. Probably before you bought your car 2 years ago I decided I didnt need to go that route, still havent had a combo I couldnt tune with the MAF on it. Im doing a speed density setup in a month or two not because of necessity, but because of packaging issues. Im sure driveability coudl get even more refined with a SD tune on some cars, but without a load dyno your talkign lotsa time, and money for most guys
Magnus car is built to go fast. WOT tuning is the EASIEST stuff to tune, speed desnity would not cause much problem there. Its hitting everywhere and talking the MAF out of the loop not helping to account for the weather that adds the work. Remeber two days ago when you said your car was acting like a carburetor car? Ask Keith what took more time, WOT, or everythign under it
Its not SD sux, its that its something else to do - thats what I said. I ran in SD two years ago on a car. Time wasnt justifiable, car didnt need it, just wanted to learn what functions when the MAF is dropped out of the loop. This is before LS1 Tech and Hp tuner and the aussie guys got on here and started pointing people the right way. I think its good that you are trying diffferent stuff to work out your problem
2 years ago I decided I didnt need to go that route, still havent had a combo I couldnt tune with the MAF on it. Im doing a speed density setup in a month or two not because of necessity, but because of packaging issues. Im sure driveability coudl get even more refined with a SD tune on some cars, but without a load dyno your talkign lotsa time, and money for most guysMagnus car is built to go fast. WOT tuning is the EASIEST stuff to tune, speed desnity would not cause much problem there. Its hitting everywhere and talking the MAF out of the loop not helping to account for the weather that adds the work. Remeber two days ago when you said your car was acting like a carburetor car? Ask Keith what took more time, WOT, or everythign under it
Its not SD sux, its that its something else to do - thats what I said. I ran in SD two years ago on a car. Time wasnt justifiable, car didnt need it, just wanted to learn what functions when the MAF is dropped out of the loop. This is before LS1 Tech and Hp tuner and the aussie guys got on here and started pointing people the right way. I think its good that you are trying diffferent stuff to work out your problem
Excellent post!!! I wish I could have said it better - but I can't!!
SD works great on " Race Cars". Established fact.
SD is highly promoted Down Under for "Drivers".
Some believe the time intensive SD tune on a load dyno ( $1000 Aussie) and it's reward to the Tuners is a strong motivating factor for the hype.
I Love my MAF!!!
joel
09-22-2004, 07:17 PM
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Man, I thought this thread bit the big one. Well since it is back to the top, how are the other SD tuners doing out there? I haven't had much time to play with mine, but I have been enjoying it. My SD tune that is.
09-22-2004, 10:14 PM
#94
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Originally Posted by Another_User
Man, I thought this thread bit the big one. Well since it is back to the top, how are the other SD tuners doing out there? I haven't had much time to play with mine, but I have been enjoying it. My SD tune that is.
car's at Speed Inc all week , having true duals w/pre-axle turn downs installed 
I did find that the car doesn't like it when the A/C is on though, i'll scan and fix that this weekend hopefully
09-23-2004, 04:07 AM
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wow, this is along thread !!
I think of SD tuning this way...
The PCM fueling works by commanding a certain AFR. Closed loop mode, the Open Loop F/A, the PE table, etc. are just ways of commanding that AFR.
In the ideal world, in either MAF or MAFless configurations, when you command 12.8:1 AFR in the PE table at WOT you should get it. If you don't get that AFR then you have 3 main possibilities why:
1. Your injector flow rates are innacurate. Now, if you haven't changed your injectors, your fuel pressure is okay etc. then it's likely that this calibration is quite accurate. ie. it is unlikely this is causing you not hitting your commanded AFR.
2. The cylinder airmass the PCM is either measuring (via MAF airflow & RPM) or calculating (via VE directly) or a combo of the two is not accurate. It's hard to get the right amount of fuel in if you can't determine how much air is in there accurately. IMHO, this is where the big innacuracy occurs. The MAF is well known not to be a super accurate device due to the nature of the technology, most folks will quote you something under +/- 10% accuracy (at least folks i've spoken to). It works well under steady state, laminar (DC) flow situations. ie. where the flow is in one direction and air density is uniform across the cross section (hardly the situation in the inlet tract). The MAF is also a comparitively slow acting device and as well as being situated away from the cylinders by a reasonable distance, a suitable transient airflow model must be used to account for filling and emptying of the inlet manifold (again enter the VE table).
3. Ignition timing advance. For arguments sake i'll assume you have the timing at optimum (this is not a straight forward as it sounds since timing is airmass based and hence anything you do that changes airflow will also change timing). Ever seen a dog running in circles chasing its tail?
If the injector flowrates and airmass is being measured or calculated accurately then your PE table should be a flat 12.8:1 (or 1.14'ish) across the board (i say 12.8 as an example but its what i use for NA engines, on aussie fuel). Since the PCM will be delivering the AFR you are asking for, why would you set it to anything else?
The real benefit of SD tuning is that you have manual control over how much air is in each cylinder at each load(MAP)/RPM point so that you can achieve the commanded AFR. The same could be done with the MAF but you have one less degree of freedom (ie. you can hit the same airflow at various MAP/RPM points) and also you have the VE table, TPS and MAP predictions poking their nose in on the transient airflow side.
Now the method you use to set the VE table can really be anything that makes sense in getting the commanded AFR to actually be the one you see on a WBO2 (or your stock O2's). Common sense is all you need.
eg. Disabling closed loop, setting the Openloop AFR to something reasonable (eg. 13.0), setting PE to 1.0, driving around or dyno'ing alot with a WBO2 noting the deviation from 13.0 and applying the relative changes to the VE table is one way. Disabling LTFT learn and looking for 0 or slightly -ve STFT's is another way... it just depends on what you have at your disposal and what mods are on you car.
The aussie trend has been driven by 2 main things, "MAFless hysteria" (the fact we had the GTS 300kw factory car released MAFLess helped this), and also the fact that all other LS1's were fitted with the small MAF. It is easy to see a 5-10 rwkw gain across the entire rev range (and more at the top end) by pulling the MAF and fitting a 4inch MAF (airbox) pipe. Now the new 2005 Holden has ETC and 85mm MAF maybe we'll see the trend turn back? Although the initial tuning results using our s/w still show the MAFless tune making more power!!
Cheers,
Chris...
I think of SD tuning this way...
The PCM fueling works by commanding a certain AFR. Closed loop mode, the Open Loop F/A, the PE table, etc. are just ways of commanding that AFR.
In the ideal world, in either MAF or MAFless configurations, when you command 12.8:1 AFR in the PE table at WOT you should get it. If you don't get that AFR then you have 3 main possibilities why:
1. Your injector flow rates are innacurate. Now, if you haven't changed your injectors, your fuel pressure is okay etc. then it's likely that this calibration is quite accurate. ie. it is unlikely this is causing you not hitting your commanded AFR.
2. The cylinder airmass the PCM is either measuring (via MAF airflow & RPM) or calculating (via VE directly) or a combo of the two is not accurate. It's hard to get the right amount of fuel in if you can't determine how much air is in there accurately. IMHO, this is where the big innacuracy occurs. The MAF is well known not to be a super accurate device due to the nature of the technology, most folks will quote you something under +/- 10% accuracy (at least folks i've spoken to). It works well under steady state, laminar (DC) flow situations. ie. where the flow is in one direction and air density is uniform across the cross section (hardly the situation in the inlet tract). The MAF is also a comparitively slow acting device and as well as being situated away from the cylinders by a reasonable distance, a suitable transient airflow model must be used to account for filling and emptying of the inlet manifold (again enter the VE table).
3. Ignition timing advance. For arguments sake i'll assume you have the timing at optimum (this is not a straight forward as it sounds since timing is airmass based and hence anything you do that changes airflow will also change timing). Ever seen a dog running in circles chasing its tail?
If the injector flowrates and airmass is being measured or calculated accurately then your PE table should be a flat 12.8:1 (or 1.14'ish) across the board (i say 12.8 as an example but its what i use for NA engines, on aussie fuel). Since the PCM will be delivering the AFR you are asking for, why would you set it to anything else?
The real benefit of SD tuning is that you have manual control over how much air is in each cylinder at each load(MAP)/RPM point so that you can achieve the commanded AFR. The same could be done with the MAF but you have one less degree of freedom (ie. you can hit the same airflow at various MAP/RPM points) and also you have the VE table, TPS and MAP predictions poking their nose in on the transient airflow side.
Now the method you use to set the VE table can really be anything that makes sense in getting the commanded AFR to actually be the one you see on a WBO2 (or your stock O2's). Common sense is all you need.
eg. Disabling closed loop, setting the Openloop AFR to something reasonable (eg. 13.0), setting PE to 1.0, driving around or dyno'ing alot with a WBO2 noting the deviation from 13.0 and applying the relative changes to the VE table is one way. Disabling LTFT learn and looking for 0 or slightly -ve STFT's is another way... it just depends on what you have at your disposal and what mods are on you car.
The aussie trend has been driven by 2 main things, "MAFless hysteria" (the fact we had the GTS 300kw factory car released MAFLess helped this), and also the fact that all other LS1's were fitted with the small MAF. It is easy to see a 5-10 rwkw gain across the entire rev range (and more at the top end) by pulling the MAF and fitting a 4inch MAF (airbox) pipe. Now the new 2005 Holden has ETC and 85mm MAF maybe we'll see the trend turn back? Although the initial tuning results using our s/w still show the MAFless tune making more power!!
Cheers,
Chris...
09-23-2004, 08:51 AM
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"eg. Disabling closed loop, setting the Openloop AFR to something reasonable (eg. 13.0), "
How would I accomplish this in HPTuners? What needs to be done to disable closed loop. I assume the 1st step would be to remove the MAF and disable any resulting codes that go with it. To disable closed loop could I go into the "closed loop enable coolant temp vs IAT" screen and set all values to an unreachable temp like 250*? I assume that would disable the closed loop from ever coming into play. Now would I place the 13.0 afr in the "Stoich AFR" field? Then make sure that the IFR is set correctly for my stock injectors, and change all PE settings to 1.0????????? From there do some driving around with either the WB02 or watching the LTFT's and get our VE in line from there. Does all of this sound correct??????? I am ready to do this, but I just want to make sure that I'm doing it right. Also I have an A4. Any input on that? You Aussie guys are doing it in A4's so I would assume that we could do it to. Personaly I think that the hole "line pressure" thing is crap. I've accidently left my MAF unplugged for a few days before and it didn't screw up my tranny.
Also after everything is dialed in for 13.0 AFR can I go back and change it to 14.7, or will it mess everything up? I assume that you could start to adjust PE from there?
How would I accomplish this in HPTuners? What needs to be done to disable closed loop. I assume the 1st step would be to remove the MAF and disable any resulting codes that go with it. To disable closed loop could I go into the "closed loop enable coolant temp vs IAT" screen and set all values to an unreachable temp like 250*? I assume that would disable the closed loop from ever coming into play. Now would I place the 13.0 afr in the "Stoich AFR" field? Then make sure that the IFR is set correctly for my stock injectors, and change all PE settings to 1.0????????? From there do some driving around with either the WB02 or watching the LTFT's and get our VE in line from there. Does all of this sound correct??????? I am ready to do this, but I just want to make sure that I'm doing it right. Also I have an A4. Any input on that? You Aussie guys are doing it in A4's so I would assume that we could do it to. Personaly I think that the hole "line pressure" thing is crap. I've accidently left my MAF unplugged for a few days before and it didn't screw up my tranny.
Also after everything is dialed in for 13.0 AFR can I go back and change it to 14.7, or will it mess everything up? I assume that you could start to adjust PE from there?
Last edited by WS6snake-eater; 09-23-2004 at 09:12 AM.
09-23-2004, 09:30 AM
#100
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Originally Posted by WS6snake-eater
"eg. Disabling closed loop, setting the Openloop AFR to something reasonable (eg. 13.0), "
How would I accomplish this in HPTuners? What needs to be done to disable closed loop. I assume the 1st step would be to remove the MAF and disable any resulting codes that go with it. To disable closed loop could I go into the "closed loop enable coolant temp vs IAT" screen and set all values to an unreachable temp like 250*? I assume that would disable the closed loop from ever coming into play.
How would I accomplish this in HPTuners? What needs to be done to disable closed loop. I assume the 1st step would be to remove the MAF and disable any resulting codes that go with it. To disable closed loop could I go into the "closed loop enable coolant temp vs IAT" screen and set all values to an unreachable temp like 250*? I assume that would disable the closed loop from ever coming into play.
Now would I place the 13.0 afr in the "Stoich AFR" field? Then make sure that the IFR is set correctly for my stock injectors, and change all PE settings to 1.0?????????
From there do some driving around with either the WB02 or watching the LTFT's and get our VE in line from there. Does all of this sound correct???????
I am ready to do this, but I just want to make sure that I'm doing it right. Also I have an A4. Any input on that? You Aussie guys are doing it in A4's so I would assume that we could do it to. Personaly I think that the hole "line pressure" thing is crap. I've accidently left my MAF unplugged for a few days before and it didn't screw up my tranny.
Also after everything is dialed in for 13.0 AFR can I go back and change it to 14.7, or will it mess everything up? I assume that you could start to adjust PE from there?
Also after everything is dialed in for 13.0 AFR can I go back and change it to 14.7, or will it mess everything up? I assume that you could start to adjust PE from there?
Yes after you dial in the ve table whatever you command the compter AFR at it should show on your WB. So whether its 14.7 (closed loop) or 15.5 lean cruise in open loop or 1.13 (12.96:1) on the pe table you will get that afr