VE tune begins, questions and observations inside
12-09-2004, 02:29 PM
#1
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Thread Starter
VE tune begins, questions and observations inside I started to re-tune my car a few days ago using the write up off the HP Tuners board
http://www.hptuners.com/forum/YaBB.p...num=1100894562
I just got a few quick questions on some observations ive made in the limited time ive been working on things.
A little background on the car, its a 6 spd, all N/A, 383 with 5.3l heads and a decent sized cam, 240/244 .608/.612 112lsa, and 1 7/8 QTP headers. Car is a 2001 so I have the newer intake, still running the stock 28.8 lb injectors. I have the stock MAF but with ported MAF ends and a lid.
Anyway, I would assume the MAF ends wouldnt matter as I've unplugged the MAF to work on the VE tune. I've followed the instructions in the write up above. In cruising/logging, my LTFT's at cruise are -12 to -14 in FTC 4, between -8 to -10 in FTC's 8 and 12 I believe. Thats from memory but just to give you an idea. In FTC's 5 and 9, the LTFT's are actually at 0, occasionally dropping to maybe -2. This on all stock fueling tables, VE, IFR, and so on. Is that normal? I would have thought it would be lean. I did plug in the MAF and drove a block, and in that shot time the the LTFT's went positive and looked like they werent comming back down. I just didnt think with modifications like mine that it would run so rich down low, yet be perfect at slightly higer RPM's (FTC's 5, 9 and 13). I tried adjusting those spots on the VE table, 1200-2000rpm between MAP 40 and 75, but it didnt seem to have made any difference. Well I take that back, FTC 12 has come down to a more reasonable range (-3 to -4), FTC 4 and 8 seem to be my biggest problem. I adjusted that by 15% (multiplied by .85) to bring that number down and its still the same. FTC 4 is still between -12 and -14 and FTC 8 is between -8 and -10. Any thoughts or should I just keep adjusting. If I were to keep adjusting, it wouldnt make for a very pretty graph, though that may not matter too much.....
Also, I disabled the SES light, but not the actual MAF codes, as recomended, but the only code ive thrown so far has been p0102
http://www.hptuners.com/forum/YaBB.p...num=1100894562
I just got a few quick questions on some observations ive made in the limited time ive been working on things.
A little background on the car, its a 6 spd, all N/A, 383 with 5.3l heads and a decent sized cam, 240/244 .608/.612 112lsa, and 1 7/8 QTP headers. Car is a 2001 so I have the newer intake, still running the stock 28.8 lb injectors. I have the stock MAF but with ported MAF ends and a lid.
Anyway, I would assume the MAF ends wouldnt matter as I've unplugged the MAF to work on the VE tune. I've followed the instructions in the write up above. In cruising/logging, my LTFT's at cruise are -12 to -14 in FTC 4, between -8 to -10 in FTC's 8 and 12 I believe. Thats from memory but just to give you an idea. In FTC's 5 and 9, the LTFT's are actually at 0, occasionally dropping to maybe -2. This on all stock fueling tables, VE, IFR, and so on. Is that normal? I would have thought it would be lean. I did plug in the MAF and drove a block, and in that shot time the the LTFT's went positive and looked like they werent comming back down. I just didnt think with modifications like mine that it would run so rich down low, yet be perfect at slightly higer RPM's (FTC's 5, 9 and 13). I tried adjusting those spots on the VE table, 1200-2000rpm between MAP 40 and 75, but it didnt seem to have made any difference. Well I take that back, FTC 12 has come down to a more reasonable range (-3 to -4), FTC 4 and 8 seem to be my biggest problem. I adjusted that by 15% (multiplied by .85) to bring that number down and its still the same. FTC 4 is still between -12 and -14 and FTC 8 is between -8 and -10. Any thoughts or should I just keep adjusting. If I were to keep adjusting, it wouldnt make for a very pretty graph, though that may not matter too much.....
Also, I disabled the SES light, but not the actual MAF codes, as recomended, but the only code ive thrown so far has been p0102
12-09-2004, 03:18 PM
#2
TECH Senior Member
you can set your MAF Fail Frequency to 0, will guarantee you're in speed density mode... and still let you see what the MAF's doing
In the scanner tool you can clear your LTFTs also (assuming using HP Tuners software)... then use the Histogram watching LTFTs as a guide for modifying the VE table... (or disable LTFTs and tune off the STFTs until that's close)
In the scanner tool you can clear your LTFTs also (assuming using HP Tuners software)... then use the Histogram watching LTFTs as a guide for modifying the VE table... (or disable LTFTs and tune off the STFTs until that's close)
12-09-2004, 03:31 PM
#3
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Thread Starter
I am using HPTuners. I've used the 'reset FTC' function (not sure of the exact name off hand) and the FTC's seem normal for a few minuets then work their way back down to -12 to -14. I've already reduced the lower part of my VE table (FTC's 4 and 8) by 15% (multiplied by .85) and no change. Do you suggest I keep goin? Just seems like a drastic reduction from the stock VE table, given all the mods I've added.
You think I should plug the MAF back in and set the MAF fail frequencey to 0? How would that help, being able to see what the MAF is doing? TIA
You think I should plug the MAF back in and set the MAF fail frequencey to 0? How would that help, being able to see what the MAF is doing? TIA
12-10-2004, 09:41 AM
#4
TECH Enthusiast
Thread Starter
Well, I set the MAF fail frequencey to 0 like you said, and threw the P0103 code, but that didnt change the LTFT's, so I just started making more adjustments and sure enough, things started to fall into place 
I didnt think the table would have needed to be reduced that much but apparently so! Figured it sure couldnt hurt to try. They arent terrebly consistant but are close enough to work with. Now the slightly more detailed tuning begins working into the fine tune. Hopefully sometime next week the MAF goes back on and that step of the tunung process begins
I didnt think the table would have needed to be reduced that much but apparently so! Figured it sure couldnt hurt to try. They arent terrebly consistant but are close enough to work with. Now the slightly more detailed tuning begins working into the fine tune. Hopefully sometime next week the MAF goes back on and that step of the tunung process begins
12-10-2004, 06:35 PM
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Originally Posted by horist
you can set your MAF Fail Frequency to 0, will guarantee you're in speed density mode... and still let you see what the MAF's doing
In the scanner tool you can clear your LTFTs also (assuming using HP Tuners software)... then use the Histogram watching LTFTs as a guide for modifying the VE table... (or disable LTFTs and tune off the STFTs until that's close)
In the scanner tool you can clear your LTFTs also (assuming using HP Tuners software)... then use the Histogram watching LTFTs as a guide for modifying the VE table... (or disable LTFTs and tune off the STFTs until that's close)
12-11-2004, 04:04 PM
#7
TECH Senior Member
Originally Posted by Another_User
Will this make the dynamic airflow NOT match the MAF airflow, since you are in SD mode? If so, we can use that to calibrate MAF tunes for a lid.
Hmmm.. good question... not really sure ... won't be able to test for several months either since the car's sleeping
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12-13-2004, 01:28 PM
#8
I rescaled the lower freq of my MAF table, and adjusted my VE table accordingly, in order to bring my AFR down to 14.7 -15.0 range. I was able to use DYNAIR values as a check value against the MAF values- i.e. keeping the VE within MAF range. FWIW.
12-13-2004, 01:33 PM
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Originally Posted by Another_User
Will this make the dynamic airflow NOT match the MAF airflow, since you are in SD mode? If so, we can use that to calibrate MAF tunes for a lid.
Yes this is the theory i posted about in my other thread, keep in mind the dynamic airflow is calculated from the ve table. If your ve table isnt spot on or close you wont get accurate dynamic air values and you wont derive good values for your maf table at those frequencies........