Knock retard after adding headers?

[8850]

Based on this log and tune, what should I change and how much to help eliminate knock retard? Before headers I had almost zero knock retard.

[TriPinTaZ]

There is a lot wrong with that tune.

1st - MAF table changes are not smooth at all
2nd - IAT multiplier has nearly been zero'd out where it shouldn't be. The logic in the IAT changes are wrong.
3rd - Your driver demand table hasn't been adjusted to request more torque where the car is making more torque.
4th - You've made no changes to the torque model for WOT operation
5th - Your startup idle tables are weird. I assume you are trying to minimize the startup flare and keep it quieter on cold starts. This isn't affecting the knock, but it is odd to be that aggressive. But thats just my subjective opinion.

Do you have an intake on the car? If not I imagine the car is running pretty rich at WOT.

[8850]

There is a lot wrong with that tune.

1st - MAF table changes are not smooth at all
2nd - IAT multiplier has nearly been zero'd out where it shouldn't be. The logic in the IAT changes are wrong.
3rd - Your driver demand table hasn't been adjusted to request more torque where the car is making more torque.
4th - You've made no changes to the torque model for WOT operation
5th - Your startup idle tables are weird. I assume you are trying to minimize the startup flare and keep it quieter on cold starts. This isn't affecting the knock, but it is odd to be that aggressive. But thats just my subjective opinion.

Do you have an intake on the car? If not I imagine the car is running pretty rich at WOT.

1. I was making an attempt to keep in line with the stock Eq ratio values. Not quite there on this log but a tad richer than prior to headers.
2. I'm using the GM IAT tune file for 100 octane. I'm running Boostane with enough to reach a little over 100 octane along with meth.
3. I've tried adjusting the DD table prior to headers but logged more kr at that time. I really don't know how to adjust that table other than add a couple %?
4. Correct, stock values. Can you help me with those changes?
5. Correct, just to reduce flare at start up. I did not like seeing 1500+ rpm at start up with a cold engine.

I have a BMS filter in the factory housing and a Katech ported throttle body. Based on my wideband readings in that log I'm actually a little on the lean side.
Thanks for the input!

[TriPinTaZ]

1. I was making an attempt to keep in line with the stock Eq ratio values. Not quite there on this log but a tad richer than prior to headers.
2. I'm using the GM IAT tune file for 100 octane. I'm running Boostane with enough to reach a little over 100 octane along with meth.
3. I've tried adjusting the DD table prior to headers but logged more kr at that time. I really don't know how to adjust that table other than add a couple %?
4. Correct, stock values. Can you help me with those changes?
5. Correct, just to reduce flare at start up. I did not like seeing 1500+ rpm at start up with a cold engine.

I have a BMS filter in the factory housing and a Katech ported throttle body. Based on my wideband readings in that log I'm actually a little on the lean side.
Thanks for the input!

Try the following to see if it helps KR

#1 On your Driver Demand Tables, increase in the following manner for all tables. Do not copy and paste between tables. Apply this to each individual table.
62% Pedal position increase by 3% for all values
74% Pedal position, increase by 5% for all values
86% Pedal position, increase by 7% for all values
100% Pedal position, increase by 10% for all values


#2 See if lowering your knock sensor multipliers help any since you're running 100 octane. I would try this separately though and probably after you take more logs with the below mentioned PID's.



Also, you need to log the following PIDs or your logs are useless in a torque based system:
Driver Demand Torque Request
Immediate Axle Torque Commanded
Actual Axle Torque
Peak Engine Torque
Maximum Engine Torque
Immediate Engine Torque
Engine Torque

I log more than this but these are the main ones that will tell if you have a torque limiting issue somewhere.

[8850]

Here's a few pics and a modified file of what you are referring. Will try the DD and the channels you suggest. I've snipped the config. that I've added. Is this the knock sensor multipliers tables as a second try? How much would you lower. Need to stay safe should I get real knock. If it ever stops raining here. lol Really appreciate the help!

[TriPinTaZ]

Here's a few pics and a modified file of what you are referring. Will try the DD and the channels you suggest. I've snipped the config. that I've added. Is this the knock sensor multipliers tables as a second try? How much would you lower. Need to stay safe should I get real knock. If it ever stops raining here. lol Really appreciate the help!

Spark>Knock Sensors>Knock Sensor Level
Multipliers Cyl 1-8
-Change any numbers below 4000 to 4000.

Under the Transient button
-Change any value that is 5.000 to 4.000

This should be a safe enough change to leave in the tune permanently. It is a little bit on the conservative side.

Also, if you are logging the right PID, your Throttle is only opening 39% while your foot (Driver Pedal) is asking for 100%. You definitely have some torque issues but we cant see whats up until you get a log with all of the PID's I've mentioned in this thread. This could actually be the primary cause of your Spark Knock. You need to get the Torque Tables, Torque Limits, and Driver Demand sorted out.

[[email protected]]

SUBBED to see what your outcome is.
keep us posted.

[paulsmithsr]

I don?t change knock settings. - be carefull dangerous if u de-sensitized knock sensor
Since tune is far off probably false knock

[8850]

Spark>Knock Sensors>Knock Sensor Level
Multipliers Cyl 1-8
-Change any numbers below 4000 to 4000.

Under the Transient button
-Change any value that is 5.000 to 4.000

This should be a safe enough change to leave in the tune permanently. It is a little bit on the conservative side.

Also, if you are logging the right PID, your Throttle is only opening 39% while your foot (Driver Pedal) is asking for 100%. You definitely have some torque issues but we cant see whats up until you get a log with all of the PID's I've mentioned in this thread. This could actually be the primary cause of your Spark Knock. You need to get the Torque Tables, Torque Limits, and Driver Demand sorted out.

I'm going to start with the DD changes and see if that helps eliminate kr. While logging with your added PIDs. We will see what that does for kr and go from there. Assuming it ever stops raining.

I know my log says 39% throttle opening but I ran a 137.51 mph before headers a couple weeks ago with bolt-ons. I did have more kr in that pass than I normally have on the street. Also hit the rpm limiter on the 1-2 but still managed a 10.36. 1.57 60'

[TriPinTaZ]

I don?t change knock settings. - be carefull dangerous if u de-sensitized knock sensor
Since tune is far off probably false knock

Agreed. I only suggested changing the knock sensor sensitivity because he was running 100 octane. And my changes aren't dangerous.

I'm going to start with the DD changes and see if that helps eliminate kr. While logging with your added PIDs. We will see what that does for kr and go from there. Assuming it ever stops raining.

I know my log says 39% throttle opening but I ran a 137.51 mph before headers a couple weeks ago with bolt-ons. I did have more kr in that pass than I normally have on the street. Also hit the rpm limiter on the 1-2 but still managed a 10.36. 1.57 60'

I am going to guess you are monitoring the wrong PID for TPS% then. Try re-adding the PID but do not let it tell you to use the general sensor, specify the PID and then say "yes I know what I am doing". This will give you an accurate reading of true throttle blade position. I still think your torque model/DD/ and limiters are off if you're running 137MPH in the 1/4 mile. How much more boost are you running than factory? Do you have a pulley(s)? Ported blower? Etc.

[Ghostnotes]

I had tons of false knock when I went forced. Scared the daylights out of me.Went as far as having a knock box hooked up so I could listen for it, was getting like 12* false starting around 2500ish

[8850]

I am going to guess you are monitoring the wrong PID for TPS% then. Try re-adding the PID but do not let it tell you to use the general sensor, specify the PID and then say "yes I know what I am doing". This will give you an accurate reading of true throttle blade position. I still think your torque model/DD/ and limiters are off if you're running 137MPH in the 1/4 mile. How much more boost are you running than factory? Do you have a pulley(s)? Ported blower? Etc.

May be right on wrong PID for TPS. These say ratio but are % when selected on my config.

I installed a 9% Innovators West crank pulley. It makes 1-2 psi over stock. Stock blower, upper pulley and snout. I do have a catless pipe too.

[8850]

Agreed. I only suggested changing the knock sensor sensitivity because he was running 100 octane. And my changes aren't dangerous.





I am going to guess you are monitoring the wrong PID for TPS% then. Try re-adding the PID but do not let it tell you to use the general sensor, specify the PID and then say "yes I know what I am doing". This will give you an accurate reading of true throttle blade position. I still think your torque model/DD/ and limiters are off if you're running 137MPH in the 1/4 mile. How much more boost are you running than factory? Do you have a pulley(s)? Ported blower? Etc.

Here are a couple pulls I ran this morning. Almost got rained out but got two in. Definitely less kr from a couple days ago! Maybe acceptable? The table and chart don't seem to match but that's nothing new. Still need a little more tweaking to my MAF table. Thanks again for all of your input Tri!

[TriPinTaZ]

You left out the PID "Driver Demand Torque Request". This is important to see what the ECU thinks the driver is asking for so you will want to add this. So I can't tell if there is an issue here or not. You will also want to monitor "Cam Spark", "Intake Cam Desired Angle", and "Intake Cam Angle(actual).

Based on the logs I saw though, your Peak Engine Torque value is too low below 5000 RPMs. The airmass changes has the ECU calculating a high amount of "Max Engine Torque" and it is too close to "Peak Engine Torque" below 5000 RPMs. This could also be why there is KR. Try raising the Peak Engine Torque by about 50-70 ftlbs below 5000 RPM.


I would make some suggestions on the Virtual Torque tables but I cannot without the PID's mentioned above.


A couple other suggestions:

Fuel>Oxygen Sensors> Rich/Lean vs Airflow
-Change the Max rich and Max lean values to 450mV. Since the O2's are further away from the exhaust ports on the heads this will help keep the O2's from reacting too slow. This is typically a standard change when adding headers.

Spark>Advance> Fuel > Gas (PE/COT Spark Advance Corrections)
-Typicality this table is zero'd out unless you are using it for additional timing logic. I prefer to not use this table at all, but I see in your logs this table is adding additional spark. If it is part of your timing logic there is nothing wrong with using this table.

[32vape]

On those last two logs, looks like that knock is coming from spark>retard>static retard>vs. cylinder table. The spikes are burst knock.

[8850]

You left out the PID "Driver Demand Torque Request". This is important to see what the ECU thinks the driver is asking for so you will want to add this. So I can't tell if there is an issue here or not. You will also want to monitor "Cam Spark", "Intake Cam Desired Angle", and "Intake Cam Angle(actual).

Based on the logs I saw though, your Peak Engine Torque value is too low below 5000 RPMs. The airmass changes has the ECU calculating a high amount of "Max Engine Torque" and it is too close to "Peak Engine Torque" below 5000 RPMs. This could also be why there is KR. Try raising the Peak Engine Torque by about 50-70 ftlbs below 5000 RPM.


I would make some suggestions on the Virtual Torque tables but I cannot without the PID's mentioned above.


A couple other suggestions:

Fuel>Oxygen Sensors> Rich/Lean vs Airflow
-Change the Max rich and Max lean values to 450mV. Since the O2's are further away from the exhaust ports on the heads this will help keep the O2's from reacting too slow. This is typically a standard change when adding headers.

Spark>Advance> Fuel > Gas (PE/COT Spark Advance Corrections)
-Typicality this table is zero'd out unless you are using it for additional timing logic. I prefer to not use this table at all, but I see in your logs this table is adding additional spark. If it is part of your timing logic there is nothing wrong with using this table.

I've added the PIDs with the exception of "Driver Demand Torque Request". Can't find that one. Revised Peak Engine Torque. Added 50#.

My 02s are in the stock position. I have the Hooker shorty headers. Should the 450mV still be changed?

Fuel, Gas zeroed. It had stock values in the table.

[TriPinTaZ]

I've added the PIDs with the exception of "Driver Demand Torque Request". Can't find that one. Revised Peak Engine Torque. Added 50#.

My 02s are in the stock position. I have the Hooker shorty headers. Should the 450mV still be changed?

Fuel, Gas zeroed. It had stock values in the table.

Ah Sorry I have the PID named something slightly different in my graphs. The actual Driver Demand PID is called "Driver Pedal Axle Torque Requested". As for the shorties, yes you should leave it at the stock values of 350/550. Only Mids and Longtubes need this change.

[8850]

Ah Sorry I have the PID named something slightly different in my graphs. The actual Driver Demand PID is called "Driver Pedal Axle Torque Requested". As for the shorties, yes you should leave it at the stock values of 350/550. Only Mids and Longtubes need this change.

No problem! Now to get the streets dry again.

[8850]

Here's a quick log TriPin. Had to let up and go back into it but hopefully you can determine something from this. Was in 3rd gear too.

Seems like the wideband reacts fairly slow as compared to the MAF sensor? We need a "Max rich and Max lean" control for the wideband! lol

[paulsmithsr]

If all Else —- fails Just IM me And I get u straight