About ready to give up on VE tuning, please help..
11-09-2004, 03:25 PM
#1
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About ready to give up on VE tuning, please help.. I disabled Ltrims and copied my high octane to low octane timing, reset trims and watched my strims and got what i thought was pretty good:
Then, I reenabled Ltrims and reset trims logging some more and it still looked good:
Lastly, i plugged in my MAF and all hell broke loose:
Why in the heck does the MAF keep doing this? What am I missing here? Am I doing something wrong??
Thanks
dave
Then, I reenabled Ltrims and reset trims logging some more and it still looked good:
Lastly, i plugged in my MAF and all hell broke loose:
Why in the heck does the MAF keep doing this? What am I missing here? Am I doing something wrong??
Thanks
dave
11-09-2004, 04:28 PM
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Must..scale....MAF tables. You want it to add fuel, so multiply the entire table by like 1.08. I think that should put you in the ballpark. You need to use the same technique that is used when people tune their trims with MAF table.
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11-09-2004, 04:53 PM
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the main reason i even started VE tuning was to do away w/ -8 to -10 idle trims when i modified the IFR table. If scaling the MAF table will do the same thing im chasing my tail here some what. There is no way to change the MAF table based on rpm just airflow correct? So in theory when the middle rpms are -2 or so, my idle and above say 3k rpms will be -8 or so it seems.
im somewhat confused
Dave
im somewhat confused
Dave
11-09-2004, 05:01 PM
#9
Well, heres how I started scaling my MAF table after my VE was in order. I scaled the whole thing from a stock table (in my case it was x 1.45 
). After it was scaled, my idle was still a little lean, meaning I had LTFTs of 0 where the rest was -4. I added ~.25 to the whole MAF table. The nature of the maf table's curve means that the addition affected low flow much more than it affected higher flow. You will probably have to subtract a little bit after scaling. It should be able to get you closer, anyway.
-T
). After it was scaled, my idle was still a little lean, meaning I had LTFTs of 0 where the rest was -4. I added ~.25 to the whole MAF table. The nature of the maf table's curve means that the addition affected low flow much more than it affected higher flow. You will probably have to subtract a little bit after scaling. It should be able to get you closer, anyway.-T
11-09-2004, 05:24 PM
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Do you believe the MAF matches stock calibration?
Or is it aftermarket, ported, spooged up by a K&N?
Do you believe your injectors and fuel system match
stock?
These would indicate whether these want their
tables messed with, or put to stock and the answer
found in other things.
Or is it aftermarket, ported, spooged up by a K&N?
Do you believe your injectors and fuel system match
stock?
These would indicate whether these want their
tables messed with, or put to stock and the answer
found in other things.
11-10-2004, 12:30 AM
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ok i scaled my maf by 105% and everythihng looks better. Kinda odd watching the ltrims as sometimes they will go positive 0.8 then come back -0.8 but overall its looking good:
dave
dave
11-10-2004, 06:42 AM
#15
You can also modify just one part of the MAF table.
I had cells 0 1 4 5 much lower than the others and lowering the low MAF frequency did solve the problem (now -2 LTFT from cell 0 to 19).
This works for my stock MAF:
cell 0 = 0-2400 Hz
cell 1 and 4 = 2400-3200 Mz
cell 5 = 3400-4200 Hz
You can't tune each cell but you can adjust the low RPM vs. low MAP region.
I had cells 0 1 4 5 much lower than the others and lowering the low MAF frequency did solve the problem (now -2 LTFT from cell 0 to 19).
This works for my stock MAF:
cell 0 = 0-2400 Hz
cell 1 and 4 = 2400-3200 Mz
cell 5 = 3400-4200 Hz
You can't tune each cell but you can adjust the low RPM vs. low MAP region.
11-10-2004, 10:08 AM
#16
All it takes is tweaking. Experiment. 
For the most part, your LTFTs look pretty good and with some more driving they should become all the more uniform. Like tici said, modify the left most part of the MAF table if you want to slightly raise your green LTFTs at the top right of the histogram. Or you can experiment with adding a negative number, like -.25 across the whole table. This has a natural "roll off" effect in that it affects the lower numbers far greater than the higher numbers, percentage wise.
For the most part, your LTFTs look pretty good and with some more driving they should become all the more uniform. Like tici said, modify the left most part of the MAF table if you want to slightly raise your green LTFTs at the top right of the histogram. Or you can experiment with adding a negative number, like -.25 across the whole table. This has a natural "roll off" effect in that it affects the lower numbers far greater than the higher numbers, percentage wise.
11-10-2004, 04:22 PM
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I would think you should change the entire scale. The low-ends are skewed by idle and deceleration cells, while the top end cells are skewed because the airflow is starting to catch up with how far off the MAF is.