VE tuning questions...
08-16-2006, 12:41 PM
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VE tuning questions... I have a H/C '98 corvette.
It is running really rich @ lower RPM,MAP values (-18 -25)
I am attempting to VE tune via fuel trims.
It is my understanding that I must first make the changes to the secondary VE table as that is what the car relies on when in SD/OL.
My question is since the primary table is in 5 KPA increments and the secondary is in 10 KPA increments how will this affect the primary table after I copy the data over from the secondary??
There is no data for the KPA's that end in 5's
Assuming I can get my trims in order (-4 +4) can I revisit the primary in closed loop and log LTFT's under 4000 RPM to fine tune the primary table or is this even necessary?
Also what do I do with the secondary table when finished?
Does it go back to stock or should it mirror the primary table?
Any help would be welcome...
It is running really rich @ lower RPM,MAP values (-18 -25)
I am attempting to VE tune via fuel trims.
It is my understanding that I must first make the changes to the secondary VE table as that is what the car relies on when in SD/OL.
My question is since the primary table is in 5 KPA increments and the secondary is in 10 KPA increments how will this affect the primary table after I copy the data over from the secondary??
There is no data for the KPA's that end in 5's
Assuming I can get my trims in order (-4 +4) can I revisit the primary in closed loop and log LTFT's under 4000 RPM to fine tune the primary table or is this even necessary?
Also what do I do with the secondary table when finished?
Does it go back to stock or should it mirror the primary table?
Any help would be welcome...
08-16-2006, 12:48 PM
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The car will run off the secondary table while you're in SD, it never even looks at the primary. The kpa ranges that you're talking about (that "end in 5") will be estimated by the PCM by averaging the (secondary) VE cells the car is running in/near at that time. So in your scanner, you'll get values for the cells that "end in 5," but they won't actually be used until you go back to MAF operation.
And yes, you want your seconary VE table to mirror your primary at all times.
And yes, you want your seconary VE table to mirror your primary at all times.
08-16-2006, 01:42 PM
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you could also make things easier and make a histogram that matches the secondary ve table instead of the using the primary. I actually have both running just to compare.
08-16-2006, 01:57 PM
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Originally Posted by ninobrn99
you could also make things easier and make a histogram that matches the secondary ve table instead of the using the primary. I actually have both running just to compare.
I have just started "tuning" so I am still learning what can and can't be done with the software.I never even used a computer until a couple of years ago and am finding all the info a little overwhelming at times.
I have read TONS of info ( alot contradictory) and am having trouble sorting it out.
I want to get a WB but I don't have the pro version( the upgrade is robbery @ $289 ) and no EGR so I will have to tie it in the AC pressure switch or rear o2 ( I haven't decided )
Thanks for the replies
and for sharing your knowledge 
i highly suggest you save up for the eio! Running a WB makes things so much easier! Trending Topics
08-17-2006, 07:50 AM
#9
Originally Posted by molson
Makes me wonder why they even have a standard interface
many people do the same as above
many people only use their unit to do simple stuff like !codes, !TM, etc. that doesnt necessarily require a wideband...and when you get enough credits to tune up to 4 vehicles you can make a good amount of your money back by doing friends that only want the same things performed
many people dont want to spend thte extra $150 knowing they can run a wideband through their EGR now
for the most part I recommend buying the pro version but if they don't take the recommendation what can ya do?
08-17-2006, 08:02 AM
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I made a table in Excel. It allowed me to paste the secondary VE table in and then took the average (midpoint) of the x0kPa cells to determine the x5kPa cells. Then, I just fine tuned with the MAF. VE is primarily there incase of a MAF failure in my opinion. If you're planning on running the MAF, get the VE close...but don't sweat the small stuff. Then, re-enable the MAF and dial it in. Just my $0.02.
08-17-2006, 12:38 PM
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I have a 99 C5 and have run into the same issue. Here's what I do:
Copy my primary VE to my secondary VE.
Smooth as necessary.
Log using a historgram that's scaled for the secondary VE.
Once I'm satisfied with my secondary VE table, I copy the values to my primary table, skipping every other row. If you've made major changes, your primary VE will now be kinda choppy, so you'll need to do some hand smoothing.
Idle cells may be an issue as the secondary VE only has 2 usable idle cells where the primary has 3 or 4.
BTW, I have a WB which makes it easier, but it doesn't eliminate the headache of having to translate values from a table with less resolution to one with more.
Copy my primary VE to my secondary VE.
Smooth as necessary.
Log using a historgram that's scaled for the secondary VE.
Once I'm satisfied with my secondary VE table, I copy the values to my primary table, skipping every other row. If you've made major changes, your primary VE will now be kinda choppy, so you'll need to do some hand smoothing.
Idle cells may be an issue as the secondary VE only has 2 usable idle cells where the primary has 3 or 4.
BTW, I have a WB which makes it easier, but it doesn't eliminate the headache of having to translate values from a table with less resolution to one with more.
08-17-2006, 01:01 PM
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Originally Posted by foff667
many dyno shops end up using the dyno's wideband plotted info to make their adjustments
many people do the same as above
many people only use their unit to do simple stuff like !codes, !TM, etc. that doesnt necessarily require a wideband...and when you get enough credits to tune up to 4 vehicles you can make a good amount of your money back by doing friends that only want the same things performed
many people dont want to spend thte extra $150 knowing they can run a wideband through their EGR now
for the most part I recommend buying the pro version but if they don't take the recommendation what can ya do?
many people do the same as above
many people only use their unit to do simple stuff like !codes, !TM, etc. that doesnt necessarily require a wideband...and when you get enough credits to tune up to 4 vehicles you can make a good amount of your money back by doing friends that only want the same things performed
many people dont want to spend thte extra $150 knowing they can run a wideband through their EGR now
for the most part I recommend buying the pro version but if they don't take the recommendation what can ya do?
People using it for clearing codes....you could do that with a $30 dollar scanner.
As far as my car goes (C5) you don't need anything to read/clear codes.
Even if a person wanted to use a shops dyno I think by upgrading you would still be better off and would likely spend more than $150 @ the dyno.
I just wish the upgrade for my application was a little more reasonable $$ wise.
I would gladly pay it.
I an always looking to save $ so I bought my HP tuners used...I have not seen many pro versions up for resale.
Live and learn I guess....I still think it's a great product and enjoy using it,but the WB would really speed things up and would provide better results.
Back to logging/scanning!!
08-17-2006, 01:12 PM
#13
In my opinion, some of you guys are doing it backwards. Make your corrections FIRST to the Primary VE Table and smooth as necessary, THEN copy every other row to the Secondary VE Table. This way there is no guessing what the 5KPa values will be. The Histogram will log the full resolution (increments of 5KPa), so why not use it to make the fueling corrections. There is no need for any excel spreadsheets if done this way.
08-17-2006, 01:17 PM
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Originally Posted by 12secSS
Make your corrections FIRST to the Primary VE Table and smooth as necessary, THEN copy every other row to the Secondary VE Table.
08-17-2006, 01:56 PM
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the way i do it is, log my afr error for ve using the primary ve histo, then copy and paste special multiply %/2. I look at the 3d model and see if it needs smoothing (depending on how close my error is to 0) then i copy it over to the 2ndary table. i made a histo for the secondary, but it doesnt mimic the primary one. the numbers are slightly different.
08-18-2006, 10:11 AM
#18
Originally Posted by muncie21
As soon as my MAF goes into fail mode (either by unplugging or setting MAF fail freq to zero) I get defaulted to the secondary VE table....<shrug>
08-18-2006, 12:43 PM
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Lots of good ideas here...
looks like there are many different ways to approach this.
I have done 3 or 4 scans so far and am still getting some high neg. values for the 400 800 rpm rows @ lower MAP values.
I am having issues with the car wanting to stall when coming to a stop....I tried bumping the timing up in the lower regions but it hasn't helped much.
I think the stalling is messing with those regions...Should I even worry about this.The car really shouldn't be seeing 400 rpm's anyway.
Getting alot of 0's in the higher ends of the table.
looks like there are many different ways to approach this.
I have done 3 or 4 scans so far and am still getting some high neg. values for the 400 800 rpm rows @ lower MAP values.
I am having issues with the car wanting to stall when coming to a stop....I tried bumping the timing up in the lower regions but it hasn't helped much.
I think the stalling is messing with those regions...Should I even worry about this.The car really shouldn't be seeing 400 rpm's anyway.
Getting alot of 0's in the higher ends of the table.
08-18-2006, 12:52 PM
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Sounds more fueling related than VE. The 400-800 RPM cells are also used for idle trims.
If you installed larger fuel injectors and don't have the pulse widths set right, then there's a good chance you are running rich at idle.
Finally, when you do your VE tuning, are you filtering out the Idle/decel fuel trim cells?
If you installed larger fuel injectors and don't have the pulse widths set right, then there's a good chance you are running rich at idle.
Finally, when you do your VE tuning, are you filtering out the Idle/decel fuel trim cells?