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Thread: Understanding the Dodge ETC system: Tuning for a linear throttle response with a S/C?

  1. #21
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    Thanks tbr.

    I don't suppose you have a screen shot or table ID for that one from another Dodge platform? Is it [ECM] 35100 - Maximum Flywheel Torque? I have requested this particular table a month or so a go but still no luck yet. Does anyone know if its exists on a 3.6 pentastar platform?

  2. #22
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    Some slight progress to report:

    I managed to get a descent increase in lower RPM throttle openings by significantly decreasing the throttle body airflow values from 0.2V upward.
    ThrottleAirflowReduction.JPG

    Previously (blue) I was maxing out at:

    0.64V throttle @ 1250rpm
    1.22V throttle @ 1850rpm

    With further airflow reduction (red) I'm now able to get:

    1.1V throttle @ 1250rpm
    1.7V throttle @ 1850rpm

    But it is still clipping with what seems to be a torque or airflow limit vs RPM. Increasing the DD or flywheel power request tables here does not increase the throttle opening here.
    The reason this is still an issue is when the trans downshifts, the RPMs jump up and so does this limit. Since pedal (and DD) has already been pushed past this limit you end up with a large step increase in the throttle opening and unwanted surge of acceleration.

    I'm still waiting on support to map out/add [ECM] 35100 - Maximum Flywheel Torque which I'm hoping will help solve this issue. Are there any other tables such as a Max Airflow vs RPM that anyone else is aware of on another Dodge platform?

    While I managed to get the throttle to open up more at lower RPMs by lowering the airflows (and this currently seems to be the only way to achieve that) the "rev-hang" or "cruise control" effect, when you let of the pedal at higher RPMs (4000+), is worse than ever! Now it will feed itself and start to runaway (throttle opening up further with RPM at 0 pedal). The only way to stop this is to upshift, brake or cut the ignition.

    I tweaked [ECM] 12882 - Friction Torque, giving it negative values at high RPMs and high torque areas (as suggested in one of the threads in this forum) but that didn't do a thing.

    I also tweaked [ECM] 35101 - Minimum Flywheel Torque and as the description suggests: "Represents the minimum flywheel torque request. This is the torque requested for a 0% flywheel request." it should solve this issue but it does not seem to help either.
    Because reducing the minimum flywheel torque table did not help I'm assuming that I'm running into a minimum airflow limit?

    Trawling though a heap of random tunes on here I found [ECM] 35026 - Desired Airflow Minimum: "The minimum desired airflow allowed." in an SRT-8 file. Its minimum airflow based off RPM where the airflow increases with RPM. Anyone tweaked this table before? Could this be the real cure for this darn rev-hang? I'll ask support to see if they can map/add that too.

  3. #23
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    Still been struggling with this issue.

    I had support try to find/map out [ECM] 35026 - Desired Airflow Minimum or its equivalent but they have been unable to find this parameter or similar tables on my controller..

    The did manage to add some more torque channels to the scanner:

    Indicated Torque Per Cylinder
    Actual Torque
    Torque Request
    Max Flywheel Torque
    Desired Accelerator Pedal Torque

    I still have yet to grasp the influence of these new parameters.

    One Q I do have through all this:
    Does the throttle body airflow table have to be the exact inverse of the desired throttle small and large range tables and whats the reasoning behind this?

    Conventional wisdom would say they have to match but if that's the actual case then why have these 2 sets of tables (throttle body airflow vs small/large range)? The required data already exists in the small and large range tables.

  4. #24
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    I dont know if you are trying to make this thing act like a diesel stump puller but it will never do that.
    The ETC system on these is to make the pedal FEEL linear....to get a nice, smooth, even flow of torque relative to pedal.
    That is why I say you must mess with it till it feels right...you can datalog all you like but that wont tell you what tq you are feeling.
    The tq numbers are just that...numbers....they are needed to feed into the systems related to the driveline (engine/trans etc) to get you the tq you are requesting.
    It is a request based on percentage of available tq. The tq comes from a (now supercharged) combustion engine (the tq is not linear).
    The numbers are there to quantify the tq so the pcm/tcm can make sense of the requested tq.
    The trans and the engine work together to satisfy the request.
    So when you are at 1500rpm there is not a great deal of tq available (on a 3.6l 4v enginewith peak tq at 5k) so you need to tell it to deliver a high percentage (or all) of available tq at small pedal percents.
    After this pedal percentage there is no more tq to satisfy the increasing request so ideally the trans will help out and drop a ratio (or 2), the engine will deliver more tq as will the lower trans ratio.
    As you now have more tq from the engine and the trans tq multplication of a lower gear ratio you will FEEL a heap more tq.
    The ETC system (if set up correctly) will close the TB at this higher rpm at the same pedal % so tq doesn't ramp up and you have to get out of the pedal (cable style).
    Dunno about you but the auto pentastars I do are rarely below 2000rpm unless coasting or at super-light throttle.
    It will perform waaaaay better if you utilise the trans/boost and rpm (with a blower peak power is at 7k ish) they are capable of.
    Yes they make reasonable tq down low, but they love revs and in a heavy vehicle like a wrangler they go best if you have them rev most all the time.
    Pretty sure at 100kmh with stock gearing they run like 2200rpm........keep em in this (1800-2200) zone and above.
    They pull pretty good at this rpm with boost but with a bit more pedal it should smoothly unlock the converter or drop a gear and give just a little more acceleration.
    If you need further acceleration, more pedal will give you that until again no more is available from the engine and we need more rpm and a lower ratio...a bit more pedal
    and the trans will drop another gear and off you go.
    It doesnt matter how much boost you feed it at 1500rpm, it will not stay with one that is a gear lower ( tq multiplication) and at 2500rpm.
    You dont need anymore tables than are available currently to tune these things to get a wow driving experience....
    You do need to work with the system tho and not against it ...I have tried virtually every which way tuning these and this is what I have found drives/performs the best by far.
    The small/large tables are the commanded tables, the TB table is what it thinks it is getting from the TB and feeds into the actual airflow/tq numbers ( which are not actually the actual airflow/tq, just the airflow/tq it believes it is getting/making)
    I have found best results when using stock TB if small/large tables are identical and TB table is same/very close to them.
    (you do need to fudge TB tables sometimes if you are playing with much bigger TB's, cams)
    Last edited by Hemituna; 01-03-2021 at 03:46 PM.

  5. #25
    Not sure my problem is the same, tuning NA 3.6 JK

    but if you look in attached log screenshot, i"m getting the TCM eng torque around 200-220 NM then airflow starts to bounce

    guess i"m hitting torque limit ?

    attached log file also, appreciate your feedback

    2020-09-12 00_18_21-VCM Scanner_ 2014 Jeep Wrangler Sport, 3.6 L, V6, 1C4BJWDG4EL300842 [Cutoff_.jpg
    Attached Files Attached Files

  6. #26
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    I have found once you have close to linear response tunning the air flow tables, throttle voltage vs Rpm table and DD table, the finishing touches can start to be added with Transmission tunning. My JT seems to stay at driver mode 0 and trans mode 0 most of the time and I have made changes to this table and the the adjacent ones, to downshift faster and stay in higher gears. I also tweaked the Oss limits in order to help keep the rpm over 1800 most of the time. My only issue so far is some oscillation on the throttle body at light throttle. This started happening when I made the large airflow table close to what was being dataloged from 2000 to 2800 and also adjust the TB voltage table. It worked to tame the bypass kick, but I think I am on the razors edge as the oscillation coincides with the map sensor going from 98 to 102, until load is changed. It drives well but I have popped and autostart light set like this. The surge is almost imperceptible. But it is there.

  7. #27
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    Need Help Magnuson Ram 1500 5.7

    Im having similar issues on a Magnuson Supercharged Hemi 5.7 Ram that seems to close its TPS at around 60 to 70% Accelerator Position. Starts spluttering and AFR goes WAY rich... Seriously need some help getting that ironed out.

    Quote Originally Posted by Hemituna View Post
    I dont know if you are trying to make this thing act like a diesel stump puller but it will never do that.
    The ETC system on these is to make the pedal FEEL linear....to get a nice, smooth, even flow of torque relative to pedal.
    That is why I say you must mess with it till it feels right...you can datalog all you like but that wont tell you what tq you are feeling.
    The tq numbers are just that...numbers....they are needed to feed into the systems related to the driveline (engine/trans etc) to get you the tq you are requesting.
    It is a request based on percentage of available tq. The tq comes from a (now supercharged) combustion engine (the tq is not linear).
    The numbers are there to quantify the tq so the pcm/tcm can make sense of the requested tq.
    The trans and the engine work together to satisfy the request.
    So when you are at 1500rpm there is not a great deal of tq available (on a 3.6l 4v enginewith peak tq at 5k) so you need to tell it to deliver a high percentage (or all) of available tq at small pedal percents.
    After this pedal percentage there is no more tq to satisfy the increasing request so ideally the trans will help out and drop a ratio (or 2), the engine will deliver more tq as will the lower trans ratio.
    As you now have more tq from the engine and the trans tq multplication of a lower gear ratio you will FEEL a heap more tq.
    The ETC system (if set up correctly) will close the TB at this higher rpm at the same pedal % so tq doesn't ramp up and you have to get out of the pedal (cable style).
    Dunno about you but the auto pentastars I do are rarely below 2000rpm unless coasting or at super-light throttle.
    It will perform waaaaay better if you utilise the trans/boost and rpm (with a blower peak power is at 7k ish) they are capable of.
    Yes they make reasonable tq down low, but they love revs and in a heavy vehicle like a wrangler they go best if you have them rev most all the time.
    Pretty sure at 100kmh with stock gearing they run like 2200rpm........keep em in this (1800-2200) zone and above.
    They pull pretty good at this rpm with boost but with a bit more pedal it should smoothly unlock the converter or drop a gear and give just a little more acceleration.
    If you need further acceleration, more pedal will give you that until again no more is available from the engine and we need more rpm and a lower ratio...a bit more pedal
    and the trans will drop another gear and off you go.
    It doesnt matter how much boost you feed it at 1500rpm, it will not stay with one that is a gear lower ( tq multiplication) and at 2500rpm.
    You dont need anymore tables than are available currently to tune these things to get a wow driving experience....
    You do need to work with the system tho and not against it ...I have tried virtually every which way tuning these and this is what I have found drives/performs the best by far.
    The small/large tables are the commanded tables, the TB table is what it thinks it is getting from the TB and feeds into the actual airflow/tq numbers ( which are not actually the actual airflow/tq, just the airflow/tq it believes it is getting/making)
    I have found best results if small/large are identical and TB table is same/very close to them (you can fudge it sometimes if you are playing with the tq model, but best not to generally tho)

  8. #28
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    DAVECS2,

    Any luck with this yet? I'm finding from talking to folks that this is a pretty common issue. I have a supercharged charger that does this like a light switch in the same kPa/map range. I'm still looking for the wall it keeps hitting. I've had some luck adjusting aircharge/tourque tables and some torque modeling, but nothing I'm happy with or that leads me to an aha! moment. But it is no doubt a torque limit caused by something.

  9. #29
    Quote Originally Posted by HaasExp View Post
    3. Indicated Aircharge to Torque per Cylinder - [ECM] 19645. This is the maximum torque per cylinder model. The torque request is determined by applying the power % request flywheel to this maximum torque.
    Does anyone know how this is done? Does the PCM apply WOT VE to the above 19645 table to it to get maximum torque? It doesn't seem to be doing this in my case. I'm having the same problem as HaasExp:

    Quote Originally Posted by HaasExp View Post
    With all these changes and variables eliminated the throttle opening (throttle voltage in white) is still effected by RPM and aircharge/manifold pressure/pressure ratio even though the pedal voltage (red) remains fairly constant:
    Attachment 100286
    I can't get the PCM to give me anywhere near WOT throttle voltages unless I'm WOT. This makes it impossible to modulate the throttle, because it creates a sharp transition between TPS voltages of say 1.5V (part-throttle) and 3.8V (WOT). As a result it's impossible to drive the car smoothly (or quickly in the lower gears). In the below log I've set WOT voltage to 5V, so it's easy to see how the ETC system is holding the car back:

    ussm_ngc4c_7.PNG

    Take 4,000 rpm in this log. WOT at 4,000 RPM implies an aircharge of 1,080 mg, which should produce 869 Nm of torque. However despite what should be a 100% flywheel torque request, I'm only getting 535 Nm, and 1.53 volts from the TPS. Does anyone know what's going on here?

    Thanks for any help. The car is a manual-swapped SRT8 Magnum with a 2009 manual Challenger PCM and a 7.36L naturally aspirated motor. Most of the tune is copied over from my old NGC3 (automatic) PCM, where this behavior was not exhibited.

    ussm_ngc4c_7_pt-only.hpl
    ussm_ngc4c_7_5v-pedal-wot.hpt

    (note in the above tune you'll see I've lengthed the Pedal Percent Power Request table out to 3.7V. This was an attempt to make throttle modulation easier, since the pedal goes all the way out to 3.8V. It did not have any affect on the above misbehavior)

  10. #30
    I tried changing Throttle WOT to it's NGC3 value of ~1.5 V, but that didn't seem to do anything. Same goes for messing with the Power % Request (Flywheel) table.

    Total Airflow's behavior is strange. It reads exactly as expected (given MAP, VE, RPM and IAT) during part throttle operation, but goes nuts at WOT.

  11. #31
    One thing I've noticed is that Calculated Load quickly hits 100% as you're rolling the throttle on. This seems significant, since the PCM appears to have an artificially low load / airflow limit. I'm not sure if it hits 100% exactly when TPS voltage peaks for a given RPM point or not. Edit: Nope this doesn't seem to be the case, so maybe Calculated Load is meaningless here.

    ussm_ngc4c_7_calc-load.PNG
    Last edited by Grant; 01-02-2021 at 05:05 PM.

  12. #32
    I tried two things tonight:

    1) Doubling the Power % Request (Flywheel) table. This had no effect on peak part-throttle body voltage for a given RPM.

    At WOT with Pedal WOT = 5 volts, I did notice Aircharge stays fairly flat at 750-770 mg/cyl. The factory Aircharge to torque Y axis maxes out at 800 Nm (though mine go higher); maybe this has something to do with the hidden limit I'm hitting?

    2) Halving everything to do with torque in the tune. Aircharge to Torque, Torque Airflow Factor, all the idle torque settings, etc. The idea here was to bypass a hidden torque limit. Maybe I missed something, but this didn't work quite right. Expected torque at idle was negative, and it idled and drove like crap. I'm guessing there are torque values in the tune we can't access.

    Anyway this made things worse. Peak part-throttle body voltageat say 2,000 RPM was roughly cut in half. Aircharge peaked at 450 Nm.

    This confused me more, but I could try going the opposite way and increase all torque values by say 50%. I'd probably have to spend a lot of time adjusting the rest of the tune to repair drivability though.
    Attached Files Attached Files
    Last edited by Grant; 01-08-2021 at 03:39 AM.

  13. #33
    Quote Originally Posted by HaasExp View Post
    From this airflow request I believe that the throttle body opening (voltage) is determined by the following throttle volts vs mass airflow tables which have to be equal and inverse to each other.:

    7. ETC Throttle Body Airflow - [ECM] 35035
    8. Desired Throttle Small Range - [ECM] 44388
    9. Desired Throttle Large Range - [ECM] 44387
    This is not the case with my car. Pedal inputs which should result in an airflow request of say 127 g/s do not correspond to the 127 g/s throttle body voltage. This is because the throttle body voltage tables are in volts vs. sonic airflow. To see what the actual flow would be the PCM needs to also use the ETC Throttle Phi Outflow Equation table, which means it needs to know PRatio, which means it needs some way to map an engine airflow request to a desired manifold pressure.

    It could do this with some math on the existing (VE) tables, but that's not done in other areas (TB and injector flow, Power % Request and Expected Pedal). I have a feeling there's a table or two here we cannot access in HPTuners, which makes proper throttle tuning impossible. Or at least much more difficult than it needs to be; everything I do to fix this problem creates more problems elsewhere.

    e.g. at 5,000 RPM with pedal voltage at 3.8 (WOT set to 5V; disabled), I'm seeing 1.49 throttle body volts, 69 kPA of MAP, 769 mg/cyl of aircharge and 255 g/s of total airflow. This should be a 100% torque request (wish I could log that), which the Aircharge to Torque table says would be 1,020 Nm. Per the Torque/Airflow Factor tables that would be 420 g/s of airflow, requiring more than that in sonic airflow. At 1.49 TBV I'm only getting 275 g/s of sonic airflow though.
    Last edited by Grant; 01-09-2021 at 11:03 PM.

  14. #34
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    I can't get the PCM to give me anywhere near WOT throttle voltages unless I'm WOT. This makes it impossible to modulate the throttle, because it creates a sharp transition between TPS voltages of say 1.5V (part-throttle) and 3.8V (WOT). As a result it's impossible to drive the car smoothly (or quickly in the lower gears). In the below log I've set WOT voltage to 5V, so it's easy to see how the ETC system is holding the car back:

    Take 4,000 rpm in this log. WOT at 4,000 RPM implies an aircharge of 1,080 mg, which should produce 869 Nm of torque. However despite what should be a 100% flywheel torque request, I'm only getting 535 Nm, and 1.53 volts from the TPS. Does anyone know what's going on here?




    You are getting exactly what you have asked for.
    These are a tq based system not airflow. The airflow numbers are needed to quantify the desired/actual tq from the powertrain (PCM & TCM).
    Somewhere deep in the tq tables, 535nm will equate to 250ish g/s at that rpm and the PT airflow limit at 4000 is probably something like 230-250gs..
    After the ETC has converted your tq request into a desired airflow the tb will open that amount.
    If you look at your airflow tables 250ish g/s is 1.5v.....and that is what you are getting.
    Simplest way around this is to make the airflow numbers smaller (PCM thinks the TB is smaller)
    This will make it open more for same desired g/s (if your current 250g/s was 2v or 2.5v it will open more) and the tq cal will be lower as it sees less airflow.
    Obviously you cant just change one value but rather most of the table above .3-.5v
    More complex (but ultimately better) is to rework the tq/aircharge, aircharge/tq, tq/airflow/factor tables so that more aircharge makes the same tq number.
    Then the same tq request gives you more airflow from the TB....but you have to rework the trans settings as tq numbers will now be lower for same real tq.
    If you look at the airflow limits found in diagnostics from a factory tune...you will see how small the airflow limits are.
    Raising them seems to do nothing PT so you are best to stay below them (or get more actual airflow for same number)
    Last edited by Hemituna; 01-11-2021 at 07:59 PM.

  15. #35
    Quote Originally Posted by Hemituna View Post
    If you look at your airflow tables 250ish g/s is 1.5v.....and that is what you are getting.
    1.5V of sonic airflow airflow yes, but you should need much more voltage in real-world conditions (per the phi table). I've modeled all this out and there's definitely a break at larger pedal voltages between the airflow required to fulfill the torque request and the TBV I'm seeing.

    Quote Originally Posted by Hemituna View Post
    Simple way around this is to make the airflow numbers smaller (PCM thinks the TB is smaller)
    This will make it open more for same desired g/s (if your current 250g/s was 2v or 2.5v it will open more) and the tq cal will be less as it thinks there is less airflow.
    Obviously you cant just change one value but rather most of the table above .3-.5v
    I've done this, and it solves the problem but creates others. Like getting way too much throttle at some RPMs, to where the car feels like it's going WOT all on its own, with little pedal input.

    Quote Originally Posted by Hemituna View Post
    More complex (but ultimately better) is to rework the tq/aircharge, aircharge/tq, tq/airflow/factor tables so that it takes more airflow to make the same tq number.
    I did try cutting all torque values in half, on the airflow->tq and tq->airflow tables (https://forum.hptuners.com/attachmen...2&d=1610097201), but oddly this reduced TBV. I will try only adjusting the airflow factor; since this is RPM dependent maybe I can get it to request more airflow only where I want it? Will the PCM freak out if aircharge implies a lot more than the requested airflow? Thanks!

    Quote Originally Posted by Hemituna View Post
    Then the same tq request gives you more airflow from the TB....but you have to rework the trans settings as tq numbers will now be lower for same real tq.
    If you look at the airflow limits found in diagnostics from a factory tune...you will see how small the airflow limits are.
    Raising them seems to do nothing PT so you are best to stay below them (or get more actual airflow for same number)
    Thankfully I don't have an automatic transmission to worry about. Sounds like there's some hidden airflow limit somewhere.

  16. #36
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    [QUOTE=Grant;637459]1.5V of sonic airflow airflow yes, but you should need much more voltage in real-world conditions (per the phi table). I've modeled all this out and there's definitely a break at larger pedal voltages between the airflow required to fulfill the torque request and the TBV I'm seeing.

    I wouldn't worry about the phi table....I have never had a problem hitting the targets I need with just plain old airflow numbers (keep it simple).
    Maybe the PCM uses the phi table and so does the calcs internally based on PR (so then the airflow numbers we see are basically already corrected for PR)
    Whatever, I can get the TB to behave the way I want so don't get too caught up in all the sonic flow bs.

    The max airflow on a 6.4 is set from factory at 353gs and makes 475hp.
    I see lots of guys commanding 1000+gs and have TB airflow tables similarly as big so you must all be making 2000hp..right.
    At PT the system will ignore such crazy requests and only give you up to the PT airflow limit.
    At 4000rpm this is probably around 250gs so it only opens the TB this gs amount.
    You can command more via DD etc but it will ignore you. This is the secret set-up to having a horrid stepped transition from PT into WOT that everyone loathes.
    You dont notice that this is how it works until you log it, as you usually keep pressing the pedal until you reach WOT threshold.
    Once past this threshold it barely cares about the numbers and just opens the TB fully except for max total flow or tq limits
    If you get it sorted under the limit, you can CHOOSE how much TB you want for how much pedal.
    Obviously when you now get much more TB/engine tq per pedal V, you will need to redo the ETC tables, DD and flywheel tq/rpm etc to make this all work nice.



    I've done this, and it solves the problem but creates others. Like getting way too much throttle at some RPMs, to where the car feels like it's going WOT all on its own, with little pedal input.

    You will need to adjust the other tables I mentioned above and back some of them off to work with the extra tb opening you now get (you can command less).
    Also when reducing airflow numbers you shouldn't really change the idle, off idle, overrun areas or it will cruise control or run off by itself.


    I did try cutting all torque values in half, on the airflow->tq and tq->airflow tables (https://forum.hptuners.com/attachmen...2&d=1610097201), but oddly this reduced TBV. I will try only adjusting the airflow factor; since this is RPM dependent maybe I can get it to request more airflow only where I want it? Will the PCM freak out if aircharge implies a lot more than the requested airflow? Thanks!

    Aircharge and airflow are different animals and you can have high or low of either depending on how you want to do things.
    Be aware that you are making a TORQUE request not an airflow request and the airflow/aircharge tables job is to help quantify that request.
    So you cant just cut the tq values in half unless you actually have twice as much real engine tq (think 426 4.5 whipple 25psi )
    Even then you still have to scale it using similar numbers at idle as base and then reduce tq vs aircharge thru the rest of the table so you dont go off the topend of the scale
    So same tq numbers but bigger aircharge to get to that tq.
    It needs to be nice and linear if you want a nice linear response.


    Thankfully I don't have an automatic transmission to worry about. Sounds like there's some hidden airflow limit somewhere.[/QUOTE]
    Last edited by Hemituna; 01-13-2021 at 04:11 PM.

  17. #37
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    I need to get some of my datalogs posted. I have been able to minimize the oscilation issue, but ot is nothing revolutionary, just logging and small changes to the TB airflow tables and adjusting the gains in small increments. Then tuning my shift points to stay away from areas that cause issues. It is a bit frustrating as I have a trans tune that works exceptionally well, allowing my gladiator to hold higher gears and drive very smoothly through town and traffic. The problem is when you apply moderate throttle, with this tuning and 3rd and 4th require boost and power to pull the vehicle. The throttle at first responds, but then goes into oscillation. Not sure if I am oit running the control with a proportional gain set to aggressive or if it is hiting a limit and trying over and over again. The problem only happens in third and fourth on medium to moderate throttle. I have a couple tunes where I let the engine rev and this does not happen. I loose about 2 mpg and in town and light throttle are a bit clunky as it is 2nd and third most the time.

  18. #38
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    (Quote DavecS2) I need to get some of my datalogs posted. I have been able to minimize the oscilation issue, but ot is nothing revolutionary, just logging and small changes to the TB airflow tables and adjusting the gains in small increments. Then tuning my shift points to stay away from areas that cause issues. It is a bit frustrating as I have a trans tune that works exceptionally well, allowing my gladiator to hold higher gears and drive very smoothly through town and traffic. The problem is when you apply moderate throttle, with this tuning and 3rd and 4th require boost and power to pull the vehicle. The throttle at first responds, but then goes into oscillation. Not sure if I am oit running the control with a proportional gain set to aggressive or if it is hiting a limit and trying over and over again. The problem only happens in third and fourth on medium to moderate throttle. I have a couple tunes where I let the engine rev and this does not happen. I loose about 2 mpg and in town and light throttle are a bit clunky as it is 2nd and third most the time.

    it is hitting a limit and trying over and over again.

    This
    Last edited by Hemituna; 01-12-2021 at 05:34 PM.

  19. #39
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    Just as a reference of what to aim for, here is a log file.
    Main things to watch are relative pedal vs relative throttle (tb)....then see the dd tq request and how actual tq chases that target.
    Watch the desired and actual total airflow and how they facilitate the tq number.
    Note the aircharge and how little airflow is really needed.....the airflows most use are waaaay bigger than ever needed in reality.
    This is just an early tuning log...with a bit more work the numbers will line up even better.
    FYI, this one is a 426 with 4.5 whipple, big oval TB on E85 flex (makes about 1300hp)....so about as far from the original tq model as you can get!
    Attached Files Attached Files
    Last edited by Hemituna; 01-15-2021 at 05:33 PM.

  20. #40
    Tuner in Training
    Join Date
    Jun 2020
    Posts
    34
    evo 7 data log example.png

    Here is an example of the issue I am seeing. If I could sort this out it would drive pretty well. I have attached the tune and datalog this screen shot came from

    GladiatorSCEVO7.3.hpt7.2 drive.hpl