Results 1 to 20 of 20

Thread: Trouble With Speed Density Tuning C5 LS1

  1. #1
    Tuner in Training
    Join Date
    May 2020
    Location
    Houston
    Posts
    25

    Trouble With Speed Density Tuning C5 LS1

    Hello All, first post here. Ive recently installed a mild cam, 243 heads, and longtubes on my base 99 C5. After doing so I went to first adjust the VE tables using an AEM wideband. It seems to work calculating the AFR error percentages, problem is that everytime I log it shows around 12% lean. I adjust the VE tables accordingly but it keeps showing lean. Not sure whats going on. Ive attached two logs after which I already tried adjusting the VE tables each time with no change in the log.log6.hpllog7.hpllog8.hpl

  2. #2
    Tuning Addict 5FDP's Avatar
    Join Date
    May 2012
    Location
    Rogers, MN
    Posts
    13,533
    The logs don't show that the MAF is failed for speed density tuning.

    Post your tune here.
    2016 Silverado CCSB 5.3/6L80e, not as slow but still heavy.

    If you don't post your tune and logs when you have questions you aren't helping yourself.

  3. #3
    Tuner in Training
    Join Date
    May 2020
    Location
    Houston
    Posts
    25
    that would explain my problem. Hopefully that's all it is. I set the fail frequency to 1 Hz but maybe that didnt do it. Attached is one of the tune files.99vetteVE.k.hpt

  4. #4
    Tuning Addict 5FDP's Avatar
    Join Date
    May 2012
    Location
    Rogers, MN
    Posts
    13,533
    Th 1hz is fine but you can't set the MAF dtc's to no error reported, if you do that it won't fail the MAF sensor and revert to speed density. Set all 3 codes to MIL on first error and code P0103 should be set when you are in speed density.

    Reset your primary VE table and start over. You also need to remember that this computer does not use the primary VE table in speed density, it only uses the secondary VE table. So all your changes will be done to the secondary table. You can copy in the correct rows to the primary/secondary so in the end both are the same when you go back to MAF/VE combined.


    The open loop EQ ratio must also be set to 1.00 for temps above 140 degrees. The table can not have values that are leaner or richer than 1.00 because the computer must command stoich at operating temp and the commanded AFR should only change when power enrichment is commanded.

    Speed density also reverts to the low octane timing table, so keep that in mind if it's not following your high octane timing values.
    2016 Silverado CCSB 5.3/6L80e, not as slow but still heavy.

    If you don't post your tune and logs when you have questions you aren't helping yourself.

  5. #5
    Tuner in Training
    Join Date
    May 2020
    Location
    Houston
    Posts
    25
    Thank you for the quick and thorough response. I will try these first thing tomorrow and report back the findings.

  6. #6
    Tuner in Training
    Join Date
    May 2020
    Location
    Houston
    Posts
    25
    attached is the revised tune that I will attempt first thing. I was definitely not aware that the computer uses the secondary VE tables. 99vette.rev.b.hpt

  7. #7
    Tuner in Training
    Join Date
    May 2020
    Location
    Houston
    Posts
    25
    Still having issues, I uploaded the revised tune and scanned but everytime I modify both VE tables it doesnt seem to change the AFR error (very rich). Attached are the revised tunes and scans.99vette.rev.d.hpt99vette.rev.b.hptlog1.rev.hpllog4.rev.hpl
    1999 corvette frc ls1: 243 heads, ls6 intake, TB Bypass, SE Longtubes, TI mufflers, ZZP 7.375 Pushrods, ls7 Lifters, PAC 1218, Melling 10295, A+A Blower Cam.

    2007 Avalanche: Bone Stock!

  8. #8
    Tuner in Training
    Join Date
    May 2020
    Location
    Houston
    Posts
    25
    Can anyone help point me in the right direction. I even just unplugged the MAF with the same results as I just attached. I can add the files for these as well if that helps.
    1999 corvette frc ls1: 243 heads, ls6 intake, TB Bypass, SE Longtubes, TI mufflers, ZZP 7.375 Pushrods, ls7 Lifters, PAC 1218, Melling 10295, A+A Blower Cam.

    2007 Avalanche: Bone Stock!

  9. #9
    Tuning Addict 5FDP's Avatar
    Join Date
    May 2012
    Location
    Rogers, MN
    Posts
    13,533
    Disable COT and set the LTFT enable to disabled. You also need to clear the fuel trims before gathering data with the vcm scanner.

    Is this still running stock fuel injectors and fuel pump stuff??
    2016 Silverado CCSB 5.3/6L80e, not as slow but still heavy.

    If you don't post your tune and logs when you have questions you aren't helping yourself.

  10. #10
    Tuner in Training
    Join Date
    May 2020
    Location
    Houston
    Posts
    25
    yes, stock injectors and stock fuel pump. I was afraid to disable COT because I have cats so I added a channel to watch if it was on or off. Didnt want to potentially ruin them.
    1999 corvette frc ls1: 243 heads, ls6 intake, TB Bypass, SE Longtubes, TI mufflers, ZZP 7.375 Pushrods, ls7 Lifters, PAC 1218, Melling 10295, A+A Blower Cam.

    2007 Avalanche: Bone Stock!

  11. #11
    Tuner in Training
    Join Date
    May 2020
    Location
    Houston
    Posts
    25
    still having the same issue...
    1999 corvette frc ls1: 243 heads, ls6 intake, TB Bypass, SE Longtubes, TI mufflers, ZZP 7.375 Pushrods, ls7 Lifters, PAC 1218, Melling 10295, A+A Blower Cam.

    2007 Avalanche: Bone Stock!

  12. #12
    Tuning Addict 5FDP's Avatar
    Join Date
    May 2012
    Location
    Rogers, MN
    Posts
    13,533
    Not sure what your issue is now, if the computer is in set to go into speed density with the MAF fail it should be only running off the VE tables.

    If even as a test you remove 20% worth of fuel from the VE tables and nothing happens, something weird is going on.
    2016 Silverado CCSB 5.3/6L80e, not as slow but still heavy.

    If you don't post your tune and logs when you have questions you aren't helping yourself.

  13. #13
    Tuner in Training
    Join Date
    May 2020
    Location
    Houston
    Posts
    25
    thats my dilemma what would you recommend doing next?
    1999 corvette frc ls1: 243 heads, ls6 intake, TB Bypass, SE Longtubes, TI mufflers, ZZP 7.375 Pushrods, ls7 Lifters, PAC 1218, Melling 10295, A+A Blower Cam.

    2007 Avalanche: Bone Stock!

  14. #14
    Tuner in Training
    Join Date
    May 2020
    Location
    Houston
    Posts
    25
    no check engine lights, smoke tested and no vacuum leaks, not really sure
    1999 corvette frc ls1: 243 heads, ls6 intake, TB Bypass, SE Longtubes, TI mufflers, ZZP 7.375 Pushrods, ls7 Lifters, PAC 1218, Melling 10295, A+A Blower Cam.

    2007 Avalanche: Bone Stock!

  15. #15
    Tuning Addict 5FDP's Avatar
    Join Date
    May 2012
    Location
    Rogers, MN
    Posts
    13,533
    Beats me, I'd need the car in front of me to do anything more.

    Do MAF tuning instead I guess.
    2016 Silverado CCSB 5.3/6L80e, not as slow but still heavy.

    If you don't post your tune and logs when you have questions you aren't helping yourself.

  16. #16
    Tuner in Training
    Join Date
    May 2020
    Location
    Houston
    Posts
    25
    So I took 10% away from the primary and secondary VE tables and it dropped when scanning. It seems like the cells are matching up with what its logging.log1.rev.b.hpl
    1999 corvette frc ls1: 243 heads, ls6 intake, TB Bypass, SE Longtubes, TI mufflers, ZZP 7.375 Pushrods, ls7 Lifters, PAC 1218, Melling 10295, A+A Blower Cam.

    2007 Avalanche: Bone Stock!

  17. #17
    Tuner in Training
    Join Date
    May 2020
    Location
    Houston
    Posts
    25
    to clarify I took 10% away from the whole table.
    1999 corvette frc ls1: 243 heads, ls6 intake, TB Bypass, SE Longtubes, TI mufflers, ZZP 7.375 Pushrods, ls7 Lifters, PAC 1218, Melling 10295, A+A Blower Cam.

    2007 Avalanche: Bone Stock!

  18. #18
    Tuner in Training
    Join Date
    May 2020
    Location
    Houston
    Posts
    25
    Ok, think I found the problem. When I copied the cells over from vcm scanner I modified the wrong cells. It was set up for the primary table and the values didnt transfer correctly. I will confirm this on a road test tomorrow.
    1999 corvette frc ls1: 243 heads, ls6 intake, TB Bypass, SE Longtubes, TI mufflers, ZZP 7.375 Pushrods, ls7 Lifters, PAC 1218, Melling 10295, A+A Blower Cam.

    2007 Avalanche: Bone Stock!

  19. #19
    Tuner in Training
    Join Date
    May 2020
    Location
    Houston
    Posts
    25
    Thank you 5F for leading me down the right path. Will post back findings as soon as I can confirm.
    1999 corvette frc ls1: 243 heads, ls6 intake, TB Bypass, SE Longtubes, TI mufflers, ZZP 7.375 Pushrods, ls7 Lifters, PAC 1218, Melling 10295, A+A Blower Cam.

    2007 Avalanche: Bone Stock!

  20. #20
    Tuner in Training
    Join Date
    May 2020
    Location
    Houston
    Posts
    25
    everything works when making appropriate changes to the secondary VE tables. thanks again!
    1999 corvette frc ls1: 243 heads, ls6 intake, TB Bypass, SE Longtubes, TI mufflers, ZZP 7.375 Pushrods, ls7 Lifters, PAC 1218, Melling 10295, A+A Blower Cam.

    2007 Avalanche: Bone Stock!