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Thread: Looking for improvement

  1. #1
    Potential Tuner
    Join Date
    May 2020
    Location
    South East Texas
    Posts
    5

    Looking for improvement

    Hey guys, newbie here. I've been working on Speed density for a while now and finally got my tables close enough I think. After 30-40 logs and tinkering with the VE table IMO it's close enough but I'd love for someone else to look over it and let me know if I have anything wrong.

    I have noticed that now after the tune with STFT and LTFT turned on I tend to be a tad bit lean at a cruise and pretty rich at idle. If you have any suggestions on fixing this please let me know. It may be that my WB o2 sensor is just reading lean. The only place I can put it currently is post CAT. I know there's lots of debate on that, but it responds nearly instantly and I can't relocate it so it should do the job. From what I've read lots of people tend to have the rich problem at idle with a cam that has overlap. I'm fine with it being a little rich since we live in south texas, but I don't want to waste a ton of fuel. At idle and hot it averages about 13.2. When cruising I average 14.9-15.0. At low load I don't see any problem with this. I'm always logging knock retard and I see none in the lower RPM's

    I did a log for about 30 miles earlier and I'll post it and the tune for suggestions. It was raining though so I wasn't able to go WOT with it, but I'm working on drivability right now. Please give me any suggestions you have. I have been working at this since about December, just slowly flashing tunes with different parameters taking from different tips. I feel that it's driving pretty good, much better than the tunes that I had "Professionally" done when I first cammed the truck.

    Couple of things I really want is some more low end torque. This truck will barley spin the tires off the line, and if you try to brake stand it it just sits there and hums at you. Based on previous logs No timing is being pulled, it just doesn't seem to have the balls for some reason. I really don't want a make your nose run rich idle, but if I adjust the VE table to where it's at stoic at idle I run into tip in fueling issues. I'm thinking it's because of my base idle speed, but I don't want it to idle higher. It pulls 70 kpa MAP at idle and sounds wicked.

    Looking forward to hearing from you guys.

    Timing Tuning step 1.hpt
    Timing Tuning 1.hpl
    2003 Chevrolet Silverado 1500HD
    LQ4 Modified Intake tube 224/230 111 LSA .500 Lift BTR NSR Cam Borla PRO XS Catback Exhaust

  2. #2
    Tuning Addict 5FDP's Avatar
    Join Date
    May 2012
    Location
    Rogers, MN
    Posts
    13,533
    If you are using the wideband to tune in open loop all you had to do was remove a upstream o2 sensor and put the wideband in that bung. Do your MAF and or VE changes and put the o2 sensor back in when you are done. This is the best way to avoid skewed data.

    If the trims are within 3-5% of zero on a cam swap vehicle, it's just fine. That is well within the computers ability to correct the fueling on the fly. Fine tune if you want but that's kind of a waste of time to me if it's close already. The 14.3-15.0 at cruise is okay, your trims are fine in that log.

    The choppiness of your idle timing probably doesn't help with your idling fueling and at idle is the worst for a wideband after the cat. I'm not sure how far you've taken it but a cam this size with stock injectors is probably beyond 95-100% at full throttle.

    And you can't tune in more low end torque if the parts you installed aren't going to get you that. Your camshaft choice is not a bottom end torque cam, it's shifted the power band way up. It's also a 6,500lb truck with 3.73's, deeper gears like 4.10's or 4.56's would make it a different ball game. You can try setting the ETC TPS max setting to 100 for all cells, that will stop the throttle TM.
    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
    Potential Tuner
    Join Date
    May 2020
    Location
    South East Texas
    Posts
    5
    Thank you for the tips. I've been logging for a while now and logged injector duty cycle for about the last 2 months. While I was tuning VE I noticed it actually pulling above 100 percent duty cycle, which I know just means it's wide open. I'm aware that this is going to be my limiting factor on the top end. However, after getting VE table dialed in I don't exceed 92 percent WOT at full rpm. I know the safe rule is 90 percent so I do plan to get larger injectors at some point. As for the wideband, I have it semi permanently installed in the truck which is why I didn't put it in the front o2 slot.

    I'll give the etc TPS Max setting change a shot and see if that helps it from a dig at all. I wanna say it was set at 100 when I had it tuned by the speed shop and I had trouble controlling the pedal, but that could have been a different table I'm thinking of.

    I'm aware the truck is heavy as crap, and gearing sucks. just didn't know if I was missing something somewhere. I originally found brake torque management was enabled and thought that would fix the issue but it's still a dog off the line.
    2003 Chevrolet Silverado 1500HD
    LQ4 Modified Intake tube 224/230 111 LSA .500 Lift BTR NSR Cam Borla PRO XS Catback Exhaust