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Thread: VR30DDTT multiple table explanation help

  1. #1
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    VR30DDTT multiple table explanation help

    Could someone please explain what several of these tables do?

    ECM 11899 IAT timing correction reference has values of temperature in the cells. Does it look for these temps to trigger ECM 11898 IAT base timing correction as is this multiplier subtracted from base timing?

    ECM 44173 MBT Spark Advance (SCV close)- What does SCV mean?

    ECM 35180 Max intake pressure - are these pressures including atmospheric (14.7) on top of actual boost?

    ECM 29407/29417/29429 map/boost feedback- Can you explain how these work?

    ECM 11575- throttle position request- Are the values in the cell the desired throttle percent opening vs. speed and pedal position? So you can increase these to make the car more responsive? How do I stop the throttle limit when trying to launch?

    Several tables have a basic table and then a "(Link)" table. Why are there 2?

    Is there a way to disable the EGR for those that don't run cats? Is there a way to shut off the open wastegates at cold start?

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    Bump for assistance please.

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    Post the tune.

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    Quote Originally Posted by 4wheelinls1 View Post
    Post the tune.
    Here's a stock tune.
    2018 Q50 LUXE VR30 Stock.hpt

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    Could someone please explain what several of these tables do?

    ECM 11899 IAT timing correction reference has values of temperature in the cells. Does it look for these temps to trigger ECM 11898 IAT base timing correction as is this multiplier subtracted from base timing?I would say yes but it appears there may be a table or threshold missing.

    ECM 44173 MBT Spark Advance (SCV close)- What does SCV mean? Swirl control valve would be my best guess

    ECM 35180 Max intake pressure - are these pressures including atmospheric (14.7) on top of actual boost?Don't know for sure but it would seem unlikely given the values at idle, seems more likely to be absolute. Set them to 100 kpa and see what boost is achieved

    ECM 29407/29417/29429 map/boost feedback- Can you explain how these work? This is the PID control for closed loop boost, although there appears to be no Proportional, this is how the wastegate control adjusts boost and would generally be fine for a stock turbo although Dump pipes and significant intake modifications can alter the turbo control efficiency

    ECM 11575- throttle position request- Are the values in the cell the desired throttle percent opening vs. speed and pedal position? So you can increase these to make the car more responsive? How do I stop the throttle limit when trying to launch?Yes, it looks as though you have 2 modes, normal and sport or cruise/winter. This requests full throttle at full pedal at 0 road speed so there is another table causing you to not be able to stall the car at full throttle, it may be a transmission request. Also what boost do you achieve at stall as it may be using the throttle to limit the boost which is common, you may need to raise the 35180 and 33510 to get the car to make boost stalled, however this may not work if there is a transmission or torque request we can't access.

    Several tables have a basic table and then a "(Link)" table. Why are there 2? link tables are for ECU self checks in may ecu's they appear as in inverse.

    Is there a way to disable the EGR for those that don't run cats? Is there a way to shut off the open wastegates at cold start?

  6. #6
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    Quote Originally Posted by 4wheelinls1 View Post
    Could someone please explain what several of these tables do?

    ECM 11899 IAT timing correction reference has values of temperature in the cells. Does it look for these temps to trigger ECM 11898 IAT base timing correction as is this multiplier subtracted from base timing?I would say yes but it appears there may be a table or threshold missing.

    ECM 44173 MBT Spark Advance (SCV close)- What does SCV mean? Swirl control valve would be my best guess

    ECM 35180 Max intake pressure - are these pressures including atmospheric (14.7) on top of actual boost?Don't know for sure but it would seem unlikely given the values at idle, seems more likely to be absolute. Set them to 100 kpa and see what boost is achieved

    ECM 29407/29417/29429 map/boost feedback- Can you explain how these work? This is the PID control for closed loop boost, although there appears to be no Proportional, this is how the wastegate control adjusts boost and would generally be fine for a stock turbo although Dump pipes and significant intake modifications can alter the turbo control efficiency

    ECM 11575- throttle position request- Are the values in the cell the desired throttle percent opening vs. speed and pedal position? So you can increase these to make the car more responsive? How do I stop the throttle limit when trying to launch?Yes, it looks as though you have 2 modes, normal and sport or cruise/winter. This requests full throttle at full pedal at 0 road speed so there is another table causing you to not be able to stall the car at full throttle, it may be a transmission request. Also what boost do you achieve at stall as it may be using the throttle to limit the boost which is common, you may need to raise the 35180 and 33510 to get the car to make boost stalled, however this may not work if there is a transmission or torque request we can't access.

    Several tables have a basic table and then a "(Link)" table. Why are there 2? link tables are for ECU self checks in may ecu's they appear as in inverse.

    Is there a way to disable the EGR for those that don't run cats? Is there a way to shut off the open wastegates at cold start?
    Much appreciated. Would you be able to help me with 1 more question related to logging? I've been trying to find an explanation for this and can't get anything. Please open this log and look at the Knock PID. I've never seen a knock PID that is constantly in oscillation similar to an O2 sensor. I've been trying to make heads or tails of how to actually filter and see what is real knock vs. what is not knock. Would you be able to explain this? I have a histogram setup to look at the average but it still makes no sense between the low detonation/high detonation spark tables, knock PID, and the actual timing. Thanks for any info you can lend. 1st full log-3.hpl

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    The Nissan knock strategy seem to vary a lot and HP are not on top of all of them, most of my experience is with Y62 and 370z, some won't log knock at all, many spark tables have no impact at all. I use knock ears so I am comfortable with what I am hearing when I start to play. Out of interest lower the knock threshold and see what that does to the Knock Feedback, in a 370Z the car looses significant timing and power, does this increase the feedback logging? You can't take Nissan degrees as gospel as they use some time based logic from ignition to peak cylinder pressure. You will probably fine the knock sensors are overly sensitive and with careful raising of the thresholds you will be able to see timing added, using knock ears to ensure that any legit knock is heard and adjusted for.

    Are you able to log the knock thresholds?

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    I had to flash an enhanced data stream to get knock to be a logged PID. It's 1 of the main reasons I went to an HPT flash, but as you can see I can't make heads or tails of that PID lol. I was told the VR30 tune has direct ignition control assuming you're on the low detonation table and small adjustments in timing seem to change what's in the log, but this knock thing is weird. It doesn't help that I have to pull the fan fuse or hook up a battery as the brilliant OEM decided to cause the fans to run during flashing which takes 5 minutes and a read takes 20 minutes lol. I believe this "knock feedback" PID is all we have access to.

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    Quote Originally Posted by 4wheelinls1 View Post
    The Nissan knock strategy seem to vary a lot and HP are not on top of all of them, most of my experience is with Y62 and 370z, some won't log knock at all, many spark tables have no impact at all. I use knock ears so I am comfortable with what I am hearing when I start to play. Out of interest lower the knock threshold and see what that does to the Knock Feedback, in a 370Z the car looses significant timing and power, does this increase the feedback logging? You can't take Nissan degrees as gospel as they use some time based logic from ignition to peak cylinder pressure. You will probably fine the knock sensors are overly sensitive and with careful raising of the thresholds you will be able to see timing added, using knock ears to ensure that any legit knock is heard and adjusted for.

    Are you able to log the knock thresholds?
    I cranked up the sampling rate on the PID and it looks like its a constant chop and looks identical regardless of throttle. Guessing at least that means its not detecting knock lol. See what you think.1st full log-6.hpl

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    Quote Originally Posted by ddnspider View Post
    I cranked up the sampling rate on the PID and it looks like its a constant chop and looks identical regardless of throttle. Guessing at least that means its not detecting knock lol. See what you think.1st full log-6.hpl
    It almost appears unrelated, I'd would still lower the knock threshold and see if the activity goes up, you could look at the difference between the spark table and the actual run spark, lower the knock threshold and see what impact that has on the spark and the knock feedback, that value may just float as it is the cushion the ecu uses to determine knock, if the spark drops with a lower knock threshold but the feedback does not change I'd say that is a sign that its more of a filter value than an actual reference to the level of knock.

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    Quote Originally Posted by 4wheelinls1 View Post
    It almost appears unrelated, I'd would still lower the knock threshold and see if the activity goes up, you could look at the difference between the spark table and the actual run spark, lower the knock threshold and see what impact that has on the spark and the knock feedback, that value may just float as it is the cushion the ecu uses to determine knock, if the spark drops with a lower knock threshold but the feedback does not change I'd say that is a sign that its more of a filter value than an actual reference to the level of knock.
    Agree, I'll have to try it and see what happens. Right now I've got my hands full trying to understand the wastegate/boost strategy. It's so unnecessarily complex lol. I get commanded boost once I've got enough rpm and flow, it's just lazier than I want on tip in at low rpm. It appears to start you set the default wastegate position EGR on/off tables, and then tweak the boost integral and boost feedback PID based on over/under boost from commanded l. I believe "0" is wastegate fully closed and 8 as in 8mm is WG fully open. Trying to close the default WG position and then crank up the boost integral and PID for low rpm low boost regions to get the turbos to light off faster.

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    @4wheelinsl1 would you be able to provide some suggestions on this log? Really struggling to get the turbo lit on tip in. Boost is very lazy to kick in.

    1st full log-7-wastegate changes2.hpl

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    Quote Originally Posted by ddnspider View Post
    @4wheelinsl1 would you be able to provide some suggestions on this log? Really struggling to get the turbo lit on tip in. Boost is very lazy to kick in.

    1st full log-7-wastegate changes2.hpl
    With what is in the tune and in the log it appears to be torque limiting, Traction control is off? You don't appear to be at any boost limits, it also pulls spark suggesting a limit.

    It is likely you are missing some limits, could be torque, airflow, rate of turbo acceleration, transmission. Hard to know. Probably best to log a support ticket with all the details, infolog, debug, logs, tune file and see if they can locate and add. I do see when we supercharging the Y62 similar limiting on the throttle in 1st that we don't have access to, but it is worse with traction control on.

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    Quote Originally Posted by 4wheelinls1 View Post
    With what is in the tune and in the log it appears to be torque limiting, Traction control is off? You don't appear to be at any boost limits, it also pulls spark suggesting a limit.

    It is likely you are missing some limits, could be torque, airflow, rate of turbo acceleration, transmission. Hard to know. Probably best to log a support ticket with all the details, infolog, debug, logs, tune file and see if they can locate and add. I do see when we supercharging the Y62 similar limiting on the throttle in 1st that we don't have access to, but it is worse with traction control on.
    I posted a stock tune earlier not my latest tune but I've tried everything from raising torque tables, decreasing default wastegate position, having the PID add boost aggressively for under boost situations, etc. What doesn't make sense is the wastegate positions in that log. One is almost closed and 1 is trying to stick open like I can't control banks. I submitted a help ticket for the knock sensors and the general response is that they'll look at it but they aren't tuners so they can't tell me how to use the knock feedback parameter. I'm not very confident that they'll suddenly find a missing table..... extremely frustrating to the point I want to dump the platform. I have several others interested in the outcome of this too.

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    Quote Originally Posted by ddnspider View Post
    I posted a stock tune earlier not my latest tune but I've tried everything from raising torque tables, decreasing default wastegate position, having the PID add boost aggressively for under boost situations, etc. What doesn't make sense is the wastegate positions in that log. One is almost closed and 1 is trying to stick open like I can't control banks. I submitted a help ticket for the knock sensors and the general response is that they'll look at it but they aren't tuners so they can't tell me how to use the knock feedback parameter. I'm not very confident that they'll suddenly find a missing table..... extremely frustrating to the point I want to dump the platform. I have several others interested in the outcome of this too.
    Yes I fully understand, I have found the more specific and detailed the request and the more information you can give the better, Nissan and Toyota map definitions are not as easily available as the big 3 and the Euro stuff so there is a lot more reverse engineering.