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Thread: Looking for some help on cam/headers tune LM7 5.3L (mostly spark)

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    Lightbulb Looking for some help on cam/headers tune LM7 5.3L (mostly spark)

    Hello all from Seattle WA!

    I posted here many years ago but lost my login info, so I created a new profile. Please forgive the long post, and feel free to chime in anywhere--i would genuinely appreciate any and all help and tips!

    Anyway, I have been helping a buddy who has a 2002 Silverado with the 5.3L LM7 truck engine and 4L60E. He recently swapped in a Texas Speed/Comp Cams "220R" camshaft, along with American Racing long tube headers (with hi-flo cats). The truck also has a nice resonance-tuned cold air intake/filter box and 3" dual Flowmaster cat-back exhaust. Otherwise, the powertrain is as-stock.

    The spec's of that camshaft are: 220in/220exh duration (@.050 advertised) and .581in/.581exh lift on 112LSA.

    I began tuning the truck (on the streets) using my Flashscan V2 and an Innovate LC2 wideband (serial data). The methodology I chose was CALC.VE.

    • I set up the initial tune by incorporating many tips I found in the "LS1 Idle Tips and Tricks" tutorial. This included warming up the ,0,400,800,1000,1200 timing a bit in {5932} and {5933}, and also tweaking cracker/follower decay rates, idle flare, overspeed and underspeed modifiers, and learning parameters a bit.
    • We did several data logging sessions primarily to get {B101} Main VE as close as we could on the streets. Obviously it is very difficult to get solid frame counts >50 in the high-rpm, high-load cells, but we got it to what I would consider to be about 80%. The every-day cruising (low-mid RPM, low-mid load) cells are pretty much spot-on after many revision cycles of CALC.VE.


    • Also, I should note that CALC.VE has consistently indicated a (1.0000) correction multiplier for every cell in the {B5001} MAF Sensor Calibration; which I assume is good, and correct, since the MAF is stock.


    At this point, the truck was beginning to run much better. I thought the truck idled well, albeit slightly "lopey" in neutral as low as 625-650rpm. Now my friend liked the sound of the idle being "slightly lopey", and I thought that it sounded healthy. However, eventually the CEL would illuminate due to P0300 Misfires Detected.

    After verifying that the basics---plugs, wires, and coil connections---were all good I began looking at a bunch of PIDS while cruising around, and I was noticing the total misfire counts were high just during idle and off-idle conditions. I began to think that the misfire detection regime was too "sensitive". My reasoning was, that due to the "lopey" idle characteristics of the higher-duration/lower LSA camshaft, changes in crankshaft speed were occuring much faster at low-RPM than with the stock cam, and therefore the computer was "thrown off" into thinking that uneven delay between firing events was due to misfire, when actually it was due to cam behavior. I increased values in {C5621} and {5622} by about 15-20%. The misfire counts were lower, but they were still there, and eventually P0300 would trigger. When that code would trigger, the truck would run very poorly, seemingly in limp-mode timing. So I eventually raised the idle to 700, and the P0300 went away.

    But the idle doesn't "sound as nice" (sounds even-firing and high), so at that time, on my recommendation, my friend decided to take it in to have it professionally tuned at a dyno shop.

    In a nutshell, I think he was totally ripped off.. He spent the whole day waiting on his truck, watching from the parking lot (unbeknownst to the tuner/shop owner) and my friend said that the truck was run on the dyno for a total of 30 minutes, and as far as he could tell, all he did was several WOT sweeps. The shop owner made a comment saying that he was "surprised at how well your friend was able to get the truck running", and that he would "love it now". My friend called me after driving it home, saying it was running worse than before, bucking off idle at stops, and pushing hard/high idle/"auto cruise".

    He later showed me the print out the tuner gave him, showing two WOT sweeps on a dyno jet dyno, done 45 minutes apart, the first one with a peak of ~250hp and the second one with a peak of 295hp. Based on reading and research, both my friend and thought the truck should comfortably be making 330hp at the tires on a dynojet dyno--needless to say my friend was mad after paying $450 and wasting a day of his time.

    He came over, and I pulled the tune off his truck and compared it with the tune that was on it when he went into the shop (the most recent iteration of the tune I had done). The comparison summary showed that a total of 8 parameters had been changed, and most of those changes were where he added or subtracted some small value to an entire table or a large portion of it.

    Anyways, this guy's shop is basically the only name in the game within a hundred or so miles from here, and is recommended ubiquitously by high-end (Ferrari, for instance) dealerships in the area.

    Long story short, my buddy has gotten his money back, and the owner has also agreed to allow myself and my friend access to his dyno for 4-5 hours this Saturday to tune the truck. My friend is really desperate because there are seemingly no competent tuners to tune his truck and so he is counting on me. The truck is his toy, its in flawless condition with only 30k miles and he is totally torn that it "runs like a piece of s***"

    Now finally on to my question:

    Can someone here tell me what I should do to make best use of my time on the dyno? I know the spark tables are what need the most work, but really don't know how to remap them to make the truck run correctly, and put down the best numbers safely and reliably.

    I have a feeling that I'll need to do steady-state loading on the dyno, but is there a methodology outlined in a tutorial or elsewhere that explains exactly what steps I need to follow?

    Also, as soon as I get to my PC, I will upload everything for anyone kind enough to take a look: the stock tune, the tune I did, the tune the dyno shop did, the (questionable) dyno graph, and any of the old logs I have.

    Thanks a million!

  2. #2
    Joe (Moderator) joecar's Avatar
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    You meant Calc.VET, right...?

    Leave spark tables as stock (for daily driver this gives you sufficient room to avoid knock given the variation in gasoline quality).

    Before going to dyno, make sure of the following:
    - cooling system is working flawlessly (clean out debris/leaves from radiator; bleed air out; install a new cap and make sure it works);
    - run an extra quart of 10W-30 or 0W-30 engine oil (to improve engine oil cooling) but make sure it is not frothing;
    - run an extra pint of transmission fluid (to improve ATF cooling), but make sure it is not frothing;
    - make sure axle/differential gear oil is at correct level;
    - make sure MAF and air filter are clean;
    - set PE table B3618 to something like 1.175 EQR;
    - set PE TP enable B3616 to same as 2002 Camaro.

    On dyno (prepare ahead of time) do this:

    1. modify Calc.VET procedure to use CALC.WO2BEN to correct MAF table (i.e. just like AutoMAF) while dyno holds engine at load; compare the resulting calculated VE table with existing VE table, if it looks reasonable use this new VE table (eyeball extrapolate to upper MAP/RPM).

    2. modify Calc.MAFT procedure to use CALC.WO2BEN to correct VE table (i.e. just like AutoVE) while dyno holds engine at load (when done, extrapolate VE table to cover upper MAP/RPM); if possible compare the resulting MAF table to MAF table obtained in 1. above.

    3. run the corrected MAF from 1. above and the corrected VE from 2. above to check peak HP and TQ.
    Last edited by joecar; June 18th, 2015 at 12:23 PM. Reason: correction

  3. #3
    Joe (Moderator) joecar's Avatar
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    Use the calc_pids.txt attached here (if you're not using serial comms from your WB let me know).


    Also, may I remind you of this:

    Quote Originally Posted by joecar View Post
    Serial wideband:
    anywhere that a BEN is required, use this as the new BEN: WO2BEN = {GM.EQIVRATIO}*{EXT.WO2LAM1}
    (i.e. change any BEN maps to use this and save with new filename).

    Analog wideband:
    you have to modify the WO2BEN pid to use the analog wideband lambda, e.g. WO2BEN = {GM.EQIVRATIO}*{CALC.AFR_LC11}/14.7
    (i.e. change any BEN maps to use this and save with new filename).

    Shawn's Calc.VET Tutorial and Calc.MAFT Tutorial contain calc_pids.txt files that define WO2BEN for serial wideband
    (and they also show how to define WO2BEN if you're using analog wideband).


    Explanation/comparison of various tuning procedures:

    AutoVE:
    - disable CL/LTFT,
    - disable MAF (make sure MAF DTC is present),
    - set PE safely rich to protect motor,
    - capture log,
    - create a WO2BEN map that matches B0101 (hint: copy the VE table, then in the map row/col properties click Paste Label),
    - apply transient filter to map,
    - paste-multiply map to B0101.
    Note: when MAF DTC is present, spark timing defaults to LO spark table (GM OS only)(COS continues using HO/LO adaptive spark timing).

    AutoMAF:
    - disable CL/LTFT,
    - enable MAF (make sure DTC goes away),
    - set B0120 to zero to disable VE,
    - set PE safely rich to protect motor,
    - capture log,
    - create a WO2BEN map that matches B5001 (hint: copy the MAF table, then in the map row/col properties click Paste Label),
    - apply transient filter to map,
    - paste-multiply map to B5001.

    Calc.MAFT:
    - same as AutoVE (corrects VE) but also simultaneously calculates MAF (from corrected VE),
    - can be done with or without CL/LTFT,
    - create a map for CALC.MAFT and paste this into B5001.

    Calc.VET:
    - same as AutoMAF (corrects MAF) but also simultaneously calculates VE (from corrected MAF),
    - can be done with or without CL/LTFT,
    - create a map for CALC.VET and paste this into B0101.

    Note:
    when you do Calc.VET or Calc.MAFT be aware that positive trims are added during PE,
    this has the effect of making the wideband correction ineffective,
    so you may want to add the trims to the table that is being corrected (only for PE)
    --> I'm going to make a calc pid which will add positive trims if I can figure out how to detect PE in the log.

    Shortcut: while doing AutoVE, log GM.DYNAIR, and make a B5001-like map of GM.DYNAIR, multiply it by WO2BEN, apply the transient filter, paste into B5001 as an initial MAF estimate (but note that Calc.MAFT and Calc.VET will do a better job).

    Relationships:
    - AutoMAF is a special case of Calc.VET.
    - AutoVE is a special case of Calc.MAFT.

    Note: Calc.VET and Calc.MAFT can be done with CL/LTFT disabled (in which case you use strictly WO2BEN).

    SELBEN:
    SELBEN is a combination of LTFT and WO2BEN, but you can restrict it to only WO2BEN as long as you disable CL/LTFT.

    WO2BEN:
    WO2BEN is the wideband BEN, you use this with disabled CL/LTFT.

    Concept/Intent (what they do):
    -
    Calc.VET corrects MAF and calculates VE from corrected MAF (with VE disabled).
    - Calc.MAFT corrects VE and calculates MAF from corrected VE (with MAF disabled).

    Note:
    - the thing being calculated has to be disabled,
    - the thing being corrected has to be enabled
    .

    The word "corrects" indicates "corrected by multiplying by BEN factor".
    The word "calculates" indicates "calculated and pasted in".

    Calc.MAFT is aka Reverse Calc.VET (you can see this when you compare the pids CALC.VEN and CALC.MAFN).

    Pay careful attention to:
    - is PE safely rich to protect motor,
    - is PE enabled correctly to activate at significant load,
    - is CL/LTFT enabled/disabled,
    - is MAF enabled/disabled,
    - is VE enabled/disabled,
    - what pid is being used for BEN,
    - do units match between scantool and tunetool,
    - was the transient filter applied,
    - avoid using GM.AFR for anything other than display,
    - keep pid channel count at 24 or less (to maintain fastest frame sampling rate).
    Attached Files Attached Files

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    Default Additional info as promised

    First, big thanks to you, joecar, for taking the time to synthesize all that great info into this thread.

    I wanted to post up some more info, and the tune files, so I can get into concise and specific questions; I know that first post was long, but I wanted to get the background info out of the way. I have done a ton of reading on this forum since at least 2009, and thus I have no posts to date, because I usually find what I need using search and patient reading. I say this in hopes that you won't think I am a lazy newcomer that just wants people to do their basic homework and research for them.


    1. Here is the original bone-stock 2002 factory calibration that I pulled off the truck: 96SWB's '02 Silverado LM7 Factory Cal.ctz.
    2. Here is the most recent version of the cal I came up with using CALC.VET and a serial WO2. The truck went into a professional dyno tuning shop with this file in it: 96SWB's Inital CALCVET Pre-Dyno Cal.ctz.
    3. Here is the cal that was in the truck after return from a 6 hour day spent at a dyno shop being allegedly "professionally" tuned for $450:96SWB's Current Dynoshop Cal.ctz.
    Last edited by 96SWB; June 18th, 2015 at 08:42 AM. Reason: fixing links

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    Default Dyno Graph

    Additionally here is the dyno graph provided by the tuner/dyno shop guy, which supposedly shows what the truck did when he started (with the tune file I did---see above post), and what the truck did when he was finished (again--see above post for his file):

    Click image for larger version. 

Name:	96SWB Dyno Sweep.jpg 
Views:	1051 
Size:	295.2 KB 
ID:	18532

    Now, looking at this dyno graph, and looking at the tune files in my previous post, can someone explain what changes the tuner made to account for the 26hp/13tq gain shown in this graph?

    These numbers seem very low for a 30,000mile LM7 with 220R cam, ARH stainless longtubes, resonance-tuned air intake, and dual 3" full catback?

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    Quote Originally Posted by joecar View Post
    You meant Calc.VET, right...?

    Leave spark tables as stock (for daily driver this gives you sufficient room to avoid knock given the variation in gasoline quality).
    Quote Originally Posted by joecar View Post
    You meant Calc.VET, right...?

    Leave spark tables as stock (for daily driver this gives you sufficient room to avoid knock given the variation in gasoline quality).
    .
    Joecar, to address your points:

    Yes, sorry, typo, I meant calc.vet. I've done calc.vet several times over. MAF correction multipliers were always exactly 1.0 even on the first try.

    The truck isn't a daily driver, the owner only drives it occasionally "for fun". He runs 92 octane ethanol-free fuel. With a cam swap, I thought it was pretty safe to assume that spark mapping will need pretty substantial changes due to the interrelated nature of charge density (g/cyl) and optimum advance. Aren't we leaving a lot of TQ on the table in the mid-upper RPMS by running the stock truck engine spark curves? Again his use of the truck is to play with it maybe once a month in nice weather with fresh 92oct, always from the same known source. It's not a fleet truck burning 87 pulling heavy loads all day, he wants this thing tuned for performance and fun.


    Next question: Since CALC.VET has consistently demonstrated that the MAF Cal is exactly correct (no change from stock cal) is CALC.VET really the best way to go (most accurate) tool to get my {B101} Main VE dead-nuts on, or would I be better off doing something like OL/MAFless/AutoVE on the dyno on Saturday?

    Furthermore, I think the fueling is pretty darn close at least at every RPM/MAP i was able to measure on the streets. I didn't do much work above 4000/low KPa, because the truck was accelerating way too fast to collect frame counts up. Hopefully getting into those cells on the dyno will increase the peak #'s?

    My main problem at this point are:

    • the HP/Tq numbers seem low on the dyno chart I have. 295rwhp?
    • I'm getting some KR at low-mid RPM's under high-load/low-MAP scenarios. And the truck definitely feels sluggish going up hills under normal and heavy TP/acceleration.
    • Idle throws misfire code unless set way high


    Sorry, tough to stay on point. Thanks though!

  7. #7
    Joe (Moderator) joecar's Avatar
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    Correction to post #2:

    - set PE table B3618 to something like 1.175 EQR;
    ( my fingers had typed ahead of my brain )

  8. #8
    Joe (Moderator) joecar's Avatar
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    Quote Originally Posted by 96SWB View Post
    First, big thanks to you, joecar, for taking the time to synthesize all that great info into this thread.

    I wanted to post up some more info, and the tune files, so I can get into concise and specific questions; I know that first post was long, but I wanted to get the background info out of the way. I have done a ton of reading on this forum since at least 2009, and thus I have no posts to date, because I usually find what I need using search and patient reading. I say this in hopes that you won't think I am a lazy newcomer that just wants people to do their basic homework and research for them.


    1. Here is the original bone-stock 2002 factory calibration that I pulled off the truck: 96SWB's '02 Silverado LM7 Factory Cal.ctz.
    2. Here is the most recent version of the cal I came up with using CALC.VET and a serial WO2. The truck went into a professional dyno tuning shop with this file in it: 96SWB's Inital CALCVET Pre-Dyno Cal.ctz.
    3. Here is the cal that was in the truck after return from a 6 hour day spent at a dyno shop being allegedly "professionally" tuned for $450:96SWB's Current Dynoshop Cal.ctz.
    I don't like some of the values in the stock truck tune files, we'll have to edit some of those to be safer and/or make better sense.

  9. #9
    Joe (Moderator) joecar's Avatar
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    Quote Originally Posted by 96SWB View Post
    Additionally here is the dyno graph provided by the tuner/dyno shop guy, which supposedly shows what the truck did when he started (with the tune file I did---see above post), and what the truck did when he was finished (again--see above post for his file):

    Click image for larger version. 

Name:	96SWB Dyno Sweep.jpg 
Views:	1051 
Size:	295.2 KB 
ID:	18532

    Now, looking at this dyno graph, and looking at the tune files in my previous post, can someone explain what changes the tuner made to account for the 26hp/13tq gain shown in this graph?

    These numbers seem very low for a 30,000mile LM7 with 220R cam, ARH stainless longtubes, resonance-tuned air intake, and dual 3" full catback?
    Dyno graph neglects to show AFR (or Lambda).

  10. #10
    Joe (Moderator) joecar's Avatar
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    I don't see how the gains were gotten... PE is very rich, which does favor TQ, altho it may be too rich for that, but timing was dropped a degree or two.


    I think spark timing can be advanced, use 2002 Camaro HO/LO/Base timing tables for reference, keep an eye on knock.

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