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Thread: 2015 GMC Sierra Mapping of gear for tip in limit table

  1. #21
    Advanced Tuner IARLLC's Avatar
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    Sounding good.

    Oh sure. Best to turn all of those post-cat O2 codes to "no error reported". I wasn't sure if you kept the rear O2s in place. On GEN3s we have to leave them in so I forget that others can get away with removing them.

  2. #22
    Set them to "no error" all good now. I thought by setting MIL to off it would be good enough! Feel dumb about that one. I updated the above posted file for mod8.
    Last edited by Robert C Morgillo; 07-24-2017 at 07:32 PM.

  3. #23
    Advanced Tuner IARLLC's Avatar
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    I did the same thing the first time
    Felt dumb.
    If I had done it again....
    That would be good supporting evidence for feeling that way))

  4. #24
    Advanced Tuner Redline MS's Avatar
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    Quote Originally Posted by Robert C Morgillo View Post
    Awesome Jeff! I get it fully. I am putting your suggestions into mod8. You have a lucky friend with the Suburban. I am going to wait till you can look it over to your liking. And maybe GHuggins is looking in, and can drop a comment. I wish Greg Banish (https://www.amazon.com/Greg-Banish/e/B001JOVJT2) would put out something for reading on the GenV. There is not a lot out there. I am lucky for some connection to the O.E's. I can tell you they are not as familiar as you are with "Hot Rodding" the ECM PCM's. The GenV has a lot of potential and quite a few things that can mess you up quick! Right now by far this site is the best place to follow the GM GenV. You in particular are on the "cutting edge" of this for sure. This site has a fantastic resource in you.

    Since the tune is out there. If anyone downloads it, it must be noted:
    This is an open exhaust , long, large tube open header system with long balance tubes and Cold air intake. It would be a bad idea to upload this tune to a vehicle that is not an exact duplicate. Many log runs on a controlled environment has been used so far. This tune still needs to be Dyno proven for off road use. It is quite possible this tune has way to much advance and, is far to lean for an On Highway vehicle. CAT temp could be dangerous.
    Greg is in the works for this and we may hold a class at our facility....
    Full Service GM Late Model Performance Facility

    www.redline-motorsports.net
    Follow US on FACEBOOK!
    Follow us on Instagram! redline_motorsports


  5. #25
    Quote Originally Posted by Redline MS View Post
    Greg is in the works for this and we may hold a class at our facility....
    Redline MS, Please keep me posted! I would love to hear more. I live far away. I hope you might think about maybe an online channel to the class live? Pay per View? I'm in for whatever knowledge on the GM Gen V I can get from Greg. His books are dog eared here. I need more literature from him.

    Thanks for letting me know.

  6. #26
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    Quote Originally Posted by IARLLC View Post
    This raises cylinder pressure in those regions quite a lot so it is important to log and adjust variable cam spark afterwards. Some like to just 0 out the whole low RPM region and that is understandable but I try to leave the areas that are not hurting power alone.
    I cannot wait to implement some of your advice on VCT. Seems very intuitive. I'm hesitant though to make any changes because I don't fully understand how to adjust the VC spark tables. I've tried to make associations and find a pattern where "X" amount of retard equals "y" amount of added spark advance but I can't make heads or tails out of it.

    Do you have any advice?

    Working on my '16 L86 btw.

    Thanks!

  7. #27
    Advanced Tuner IARLLC's Avatar
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    I agree. It is hard to find a direct correlation between them. Since they are already related, your adjustments to cam timing will automatically also affect spark. But since I change the shape of the cam timing tables I also like to try to similarly affect the VC table.

    If you get your main spark tables working well first, and you scan it enough to know how much kr to expect, then you can start to reduce cam retard at light/medium throttle (changing nothing else), and just log kr and see where your cam timing increased kr and take that much out of the VC spark tables.

    I refer to "increased kr" because GEN 4 and 5 get pretty weak and reduced fuel economy if you take away all KR. Of course I adjust all related tables to keep it in check but I don't take out all of the KR anymore.

  8. #28
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    Quote Originally Posted by IARLLC View Post
    Since they are already related, your adjustments to cam timing will automatically also affect spark.
    Does this mean that any changes to the "Desired Angle" table (based on your elevation) will automatically update timing accordingly? Obviously it doesn't physically change the numbers in the VCP spark tables.

    I think I'm going to do it a bit backwards (because I'm too impatient). On one extreme we have the factory settings. On the other extreme is the way I just adjusted mine. Somewhere in the middle, as you write about above, is the happy medium. I will do lots of logging on my usual commute and then slowly retard the areas that I cruise in.

    Do you have any input on how aggressively it should be blended? Another way of asking that is how quickly can I ramp out of cam retard? If I have it set at 26* at 1600 RPM and .32 g airmass - what would the next three or four airmass cells at 1600 RPM look like? With throttle input comes more speed so I assume it would blend into the 1800 RPM column some.


    For those who are interested, here is what I just did and will report back on how it feels:

    I zeroed out the Desired Angle table until 2800 RPM and started blending from .44 g airmass on up,... like this:

    VCT.JPG

    And then I made the VCP spark table look like this:

    VC Spark.JPG
    Attached Images Attached Images

  9. #29
    Advanced Tuner IARLLC's Avatar
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    You are going to notice a major increase in throttle response and some decrease in fuel mileage with all of the 0'd area at light/medium throttle. Some folks just copy the high altitude table into the mid and low altitude tables. It works and keeps some of the EGR affect (over-retard) at lighter throttle. I tend to leave as much EGR affect as possible. I just log highway driving and note what airmass I cruise at and exactly what airmass I see as I roll into the throttle. I want the EGR affect to go away pretty quickly whenever I throttle up but I leave about 60% of it in the steady cruise area to help fuel economy.

    The factory cam tables are changing cam angle very rapidly from one cell to another so yours are not risking anything with regards to that.

  10. #30
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    Yep, already see a decrease in fuel mileage haha! I've been playing with my TCC settings and I currently don't see 7th until 45 MPH and 8th until 55 MPH and the TC is unlocked 1-6. I did that because the response to inputs was just so bad with the converter locked and lugging around in high gear. I think I can actually go back to more conservative shift schedule and tcc lockup schedule now though.

    Point of clarification: do you mean past the low baro into the med and high? I only drive between sea level and 1,500 ft 99% of the time.

  11. #31
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    Quote Originally Posted by IARLLC View Post
    I want the EGR affect to go away pretty quickly whenever I throttle up but I leave about 60% of it in the steady cruise area to help fuel economy.
    This is my latest iteration.

    VCT.JPG

    VC Spark.JPG

    I combined this with modifying my lockup tables to be more conservative. Now I get lockup at around 25 MPH with low throttle input. But with these simple changes to the VCT table, as soon as I roll in to the throttle it builds speed so much better. It actually feels like it has 500 lb ft now (e85 converted).

    It also looks like there are some VCT-related correlations on the SOI base tables. Or am I crazy? Any success in adjusting those?

    SOI.JPG

  12. #32
    Advanced Tuner IARLLC's Avatar
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    You will lose hp on top with the only 2 degrees of retard. Better to paste the low altitude to the other 2 tables. You get enough increase in low rpm power that you don't need to downshift nearly as often. The rig becomes a lot more predictable at light/medium throttle.

    Yes. All of the tables will have some amount of correlation since related to airmass.

  13. #33
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    Quote Originally Posted by IARLLC View Post
    You will lose hp on top with the only 2 degrees of retard.
    I just didn't snip that portion of the table

    VCT.JPG

    I've been scouring some older threads on SOI and it seems like GHuggins and Ben Charles have got it figured out. But, understandably, hold those cards close to their chest!

  14. #34
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    Is it possible for you to post or send me the tune file?