Does anyone else see random drops in timing advance??

danielblack60 · 03-25-2017, 05:05 PM

I've only seen it happen a few times, but at the track today it happened again. I normally see 28-30 degrees at wot on e85. Today at the track it dropped as far as 12 degrees! When this happens, nothing in my logs show the reason behind the pulled timing. I am logging every channel available in regards to spark advance and I can't find anything that would cause it.

PRAY · 03-25-2017, 07:23 PM

Where did you see it? If you haven't upped your torque table 1 you are hitting limits and it will dip. It won't show in your PID's as to why. I like your style on the amount of advance on E. Do you have EFI Live? I will send you my tunes.

danielblack60 · 03-25-2017, 08:20 PM

Quote:

Originally Posted by PRAY

Where did you see it? If you haven't upped your torque table 1 you are hitting limits and it will dip. It won't show in your PID's as to why. I like your style on the amount of advance on E. Do you have EFI Live? I will send you my tunes.

It normally happens right after the 1-2 shift and lasts through the duration of the pull. I was looking on my laptop thinking I saved the log file but i guess I didn't. I haven't messed with the driver demand tables or any engine torque management really. I figured as close to stock I was it wouldn't have made much of a difference if any. Transmission tq management is all I've messed with.

On the pass it happened, I trapped 115. The next pass I changed absolutely nothing in the tune and it trapped 119 at full advance in +1800 DA. It doesn't happen often but it is a real PITA when it does lol.

PRAY · 03-28-2017, 05:40 PM

Sorry I left you hanging on this bro. You may need to detune you knock sensors which I know is a huge no, no. I know Tim had some resonance issues with his cat delete stuff and narrowed it down to a certain cell in cylinder 4 sensor table. He had to raise that one a bit to take care of it. I noticed I get some KR after shifts on pump gas. It isn't in the motor. If your knock recovery rates are set to stock then the decay rate could take forever even after the "noise" is gone. I diminish my decay rate substantially or another way to look at it is I force the motor to recover as soon as the perceived KR event is over.

cmitchell17 · 06-14-2017, 09:41 PM

I'm not sure what PID "Torque Reduction Spark Retard" cooresponds to in HP Tuners but I'm using EFI Live since it seems a little easier and more intuitive to log with.

So I posted a screenshot where the first red circle is random timing getting pulled I'm thinking. It shouldn't be traction control since that is off and I'm in Stabilitrack Competitive Mode and its not during a shift. You can see in the second red circle timing is getting pulled for the shift.

In the first red circle you can see where the actual and commanded wheel torques are staying the same as well. I guess the good thing is its only lasting about a half a second.

Megahurtz · 08-31-2017, 12:47 PM

Reviving this thread. I get the exact same Torque Management Advance killing my 5th gear. It does not happen in any other gear, well atleast not 1-4. I have not dared to take my A8 into 6th gear at WOT. 5th and I'm already doubling the speed limits on the highway.

What I see is during the shift into 5th , TMA kicks in like it should, but after the shift is done it doesn't go away, it keeps pulling about 10-12 degrees. Then it disappears and comes back in short little spurts all through 5th gear. I can literally feel the car losing and gaining power. Sucksssssss

PRAY · 08-31-2017, 02:58 PM

Quote:

Originally Posted by Megahurtz

Reviving this thread. I get the exact same Torque Management Advance killing my 5th gear. It does not happen in any other gear, well atleast not 1-4. I have not dared to take my A8 into 6th gear at WOT. 5th and I'm already doubling the speed limits on the highway.

What I see is during the shift into 5th , TMA kicks in like it should, but after the shift is done it doesn't go away, it keeps pulling about 10-12 degrees. Then it disappears and comes back in short little spurts all through 5th gear. I can literally feel the car losing and gaining power. Sucksssssss

The stuff in the tune I sent you didn't help?

1LE Red Dragon · 09-05-2017, 12:05 PM

Quote:

Originally Posted by Megahurtz

Reviving this thread. I get the exact same Torque Management Advance killing my 5th gear. It does not happen in any other gear, well atleast not 1-4. I have not dared to take my A8 into 6th gear at WOT. 5th and I'm already doubling the speed limits on the highway.

What I see is during the shift into 5th , TMA kicks in like it should, but after the shift is done it doesn't go away, it keeps pulling about 10-12 degrees. Then it disappears and comes back in short little spurts all through 5th gear. I can literally feel the car losing and gaining power. Sucksssssss

When you say you can feel the car gaining and losing power. Does it cycle like this while you are at WOT? I have the same thing that happens to me on occasion, but it happens in 3rd gear and up. I can hear it in the exhaust sound too, sounds like a surging up an down cyclical sound. Does that sound like what yours is doing?

Brian

cmitchell17 · 01-17-2018, 09:52 PM

Have we made any more progress on this? I'm just wondering for people that are running E85 and bolt ons what they need to adjust as far as torque coefficients and demanded torque go? I don't think I'm having as bad of timing pull some of y'all are having but I think it is definitely slow to ramp in and out of timing when shifting and also I think something is making it short shift at WOT. I know the E85 tables are populated but it doesn't make them correct also the torque coefficients for E85 appear to be the exact same for gas on my stock tune. I'm wondering if we should be looking at a5.3 flex fuel tune and adjusting our torque coefficients based on that?

Megahurtz · 01-18-2018, 01:30 PM

For E85 you probably need to adjust your Peak Torque tables at least. Some adjust the Torque Coefficients and some don't. It's really about making sure you stay under the limiting torque value. If you have an A8 you will need to tune your TCM as well.

Changing the Torque Coefficient tables will trick the car into seeing less torque thereby staying under the limit. You raise one set and lower the other. However, most tuners I have seen talk about this usually suggest changing Peak Torque and/or Driver Demand tables.

The issue I was seeing with the car in my OP was not related to nay of what I just said. Instead something was wrong with the TCM possibly or 2017 cars had some sort of extra Torque Management in the TCM that I couldn't see as I never had the TCM unlocked. The car still had the issue bone stock with stock tune. I've since sold the car and now have a C7 Z51 with a M7 transmission. No more TCM issues for me. I had had enough and really wanted to get back into a Vette. The Camaro is nice, but it's just not a Corvette.

cmitchell17 · 01-18-2018, 03:21 PM

Thanks for the help, I've tried both methods I haven't seen the random timing drop lately and I do have a 17. It does seem really slow on the ramp in and out of the WOT shift timing which makes it feel like it loses a lot of high rpm power. Also I heard that if your coefficients are not adjusted for e85 it will throw off WOT shift rpm which is why I think I am seeing shifts too early. This is supposed to happen even if you just copy you gas coefficients over to the e85 coefficients.

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03-25-2017, 05:05 PM	#1
danielblack60 Drives: 2016 Camaro 1SS A8, 1998 K1500 5spd Join Date: Aug 2010 Location: Russell Springs, Kentucky Posts: 172 View My Garage	Does anyone else see random drops in timing advance?? I've only seen it happen a few times, but at the track today it happened again. I normally see 28-30 degrees at wot on e85. Today at the track it dropped as far as 12 degrees! When this happens, nothing in my logs show the reason behind the pulled timing. I am logging every channel available in regards to spark advance and I can't find anything that would cause it. __________________ *2016 1SS A8-12.100 @115 Bone Stock. 11.54 @116 with cat delete, converter and dr's Previous Rides 2010 Camaro 1SS M6-12.14 @114 Bolt Ons 2014 GMC Sierra SLT 5.3/6L80

03-25-2017, 07:23 PM	#2
PRAY Drives: 2016 2SS Join Date: Jul 2016 Location: Sanford NC Posts: 2,766	Where did you see it? If you haven't upped your torque table 1 you are hitting limits and it will dip. It won't show in your PID's as to why. I like your style on the amount of advance on E. Do you have EFI Live? I will send you my tunes. __________________ 2016 2SS. H/C SBE 1.37 60ft, 6.36@109.49, 9.97@136+. Nuff Said.

03-28-2017, 05:40 PM	#4
PRAY Drives: 2016 2SS Join Date: Jul 2016 Location: Sanford NC Posts: 2,766	Sorry I left you hanging on this bro. You may need to detune you knock sensors which I know is a huge no, no. I know Tim had some resonance issues with his cat delete stuff and narrowed it down to a certain cell in cylinder 4 sensor table. He had to raise that one a bit to take care of it. I noticed I get some KR after shifts on pump gas. It isn't in the motor. If your knock recovery rates are set to stock then the decay rate could take forever even after the "noise" is gone. I diminish my decay rate substantially or another way to look at it is I force the motor to recover as soon as the perceived KR event is over. __________________ 2016 2SS. H/C SBE 1.37 60ft, 6.36@109.49, 9.97@136+. Nuff Said.

06-14-2017, 09:41 PM	#5
cmitchell17 Drives: 17 2SS, 8L90, Cam, Heads, E85 Join Date: Dec 2016 Location: US Posts: 1,201	I'm not sure what PID "Torque Reduction Spark Retard" cooresponds to in HP Tuners but I'm using EFI Live since it seems a little easier and more intuitive to log with. So I posted a screenshot where the first red circle is random timing getting pulled I'm thinking. It shouldn't be traction control since that is off and I'm in Stabilitrack Competitive Mode and its not during a shift. You can see in the second red circle timing is getting pulled for the shift. In the first red circle you can see where the actual and commanded wheel torques are staying the same as well. I guess the good thing is its only lasting about a half a second. Attached Images

08-31-2017, 12:47 PM	#6
Megahurtz Snackbar Tuning Drives: 2023 SGM ZL1 Join Date: Oct 2016 Location: Florida Posts: 1,108	Reviving this thread. I get the exact same Torque Management Advance killing my 5th gear. It does not happen in any other gear, well atleast not 1-4. I have not dared to take my A8 into 6th gear at WOT. 5th and I'm already doubling the speed limits on the highway. What I see is during the shift into 5th , TMA kicks in like it should, but after the shift is done it doesn't go away, it keeps pulling about 10-12 degrees. Then it disappears and comes back in short little spurts all through 5th gear. I can literally feel the car losing and gaining power. Sucksssssss

01-17-2018, 09:52 PM	#9
cmitchell17 Drives: 17 2SS, 8L90, Cam, Heads, E85 Join Date: Dec 2016 Location: US Posts: 1,201	Have we made any more progress on this? I'm just wondering for people that are running E85 and bolt ons what they need to adjust as far as torque coefficients and demanded torque go? I don't think I'm having as bad of timing pull some of y'all are having but I think it is definitely slow to ramp in and out of timing when shifting and also I think something is making it short shift at WOT. I know the E85 tables are populated but it doesn't make them correct also the torque coefficients for E85 appear to be the exact same for gas on my stock tune. I'm wondering if we should be looking at a5.3 flex fuel tune and adjusting our torque coefficients based on that?

01-18-2018, 01:30 PM	#10
Megahurtz Snackbar Tuning Drives: 2023 SGM ZL1 Join Date: Oct 2016 Location: Florida Posts: 1,108	For E85 you probably need to adjust your Peak Torque tables at least. Some adjust the Torque Coefficients and some don't. It's really about making sure you stay under the limiting torque value. If you have an A8 you will need to tune your TCM as well. Changing the Torque Coefficient tables will trick the car into seeing less torque thereby staying under the limit. You raise one set and lower the other. However, most tuners I have seen talk about this usually suggest changing Peak Torque and/or Driver Demand tables. The issue I was seeing with the car in my OP was not related to nay of what I just said. Instead something was wrong with the TCM possibly or 2017 cars had some sort of extra Torque Management in the TCM that I couldn't see as I never had the TCM unlocked. The car still had the issue bone stock with stock tune. I've since sold the car and now have a C7 Z51 with a M7 transmission. No more TCM issues for me. I had had enough and really wanted to get back into a Vette. The Camaro is nice, but it's just not a Corvette.

01-18-2018, 03:21 PM	#11
cmitchell17 Drives: 17 2SS, 8L90, Cam, Heads, E85 Join Date: Dec 2016 Location: US Posts: 1,201	Thanks for the help, I've tried both methods I haven't seen the random timing drop lately and I do have a 17. It does seem really slow on the ramp in and out of the WOT shift timing which makes it feel like it loses a lot of high rpm power. Also I heard that if your coefficients are not adjusted for e85 it will throw off WOT shift rpm which is why I think I am seeing shifts too early. This is supposed to happen even if you just copy you gas coefficients over to the e85 coefficients. Sent from my LG-H872 using Tapatalk

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