Ultra-strange timing behavior with Cobb - any ideas ? Pics and logs inside

[cstavaru]

@cstavaru , how are your load actual and requested in this last log posted? Can you give it a bit more resolution/scaling as well?

Very good question ! Attached to this post is a WOT log (gears 2-3) in which you can see that the load target oscillates...but in the original log posted (without increased torque limits) it does not oscillate. This can explain the timing oscillation in this log, I suppose.

As for the resolution and scaling, I am not sure what you meant so I have attached a zip containing the CSV.

[cstavaru]

Is this occurring in all cylinders? Normally we only log Cyl 1 Timing, but it might be worthwhile to log all 6.

I have logged one more cylinder (1 and 6 logged) and the timing is the same on both. So I can safely conclude that the timing is doing this on all cylinders.

[JoshBoody]

This leads me to believe that the torque limits may need DEcreasing instead of INcreasing to provide timing and boost target stability ! But this is just a supposition of mine...

From your log pics timing in the "so-so" map is much lower when not oscillating, so I think you are on to something in reducing the torque limits table values. I have thought before that this table is named incorrectly and this is more a torque to load lookup table instead of a limit. But we can only trial and error to find out.

Can you clarify the mapping:
"bad" map = only change to "good" map is higher timing targets
"so-so" = only change is torque limit table from "bad" map
"good" = based on stg2+ with altered load, timing, fuel only.
which ROM?

Good thorough testing!

[cstavaru]

From your log pics timing in the "so-so" map is much lower when not oscillating, so I think you are on to something in reducing the torque limits table values. I have thought before that this table is named incorrectly and this is more a torque to load lookup table instead of a limit. But we can only trial and error to find out.

Can you clarify the mapping:
"bad" map = only change to "good" map is higher timing targets
"so-so" = only change is torque limit table from "bad" map
"good" = based on stg2+ with altered load, timing, fuel only.
which ROM?

Good thorough testing!

Exactly, this is what I thought today too, the Load to Torque Limit may in fact be used to look up a load target from the requested torque. However Cobb did not significantly alter this map compared to the Stage 0 map. They did modify the table headers probably due to the fact that it is used to create load target from torque. But why the little modifications from lets's say 100Nm to 100.8Nm ? Doesn't make sense to me at this point. And where can you set the torque targets then ? And why is the Requested Torque always 510 ?

PS: You are correct about all the map meanings. ROM is IJE0S.

[cstavaru]

Exactly, this is what I thought today too, the Load to Torque Limit may in fact be used to look up a load target from the requested torque. However Cobb did not significantly alter this map compared to the Stage 0 map. They did modify the table headers probably due to the fact that it is used to create load target from torque. But why the little modifications from lets's say 100Nm to 100.8Nm ? Doesn't make sense to me at this point. And where can you set the torque targets then ? And why is the Requested Torque always 510 ?

PS: You are correct about all the map meanings. ROM is IJE0S.

I just realized that you can set the torque in the throttle maps ! So the circle could be complete: Press the accelerator, request a certain torque via the throttle maps, the the ECU looks up the Load to Torque Limit map (whose correct name is Torque to Load Target) and a load target is created. Just a theory.

[Josh@Cobb]

I just realized that you can set the torque in the throttle maps ! So the circle could be complete: Press the accelerator, request a certain torque via the throttle maps, the the ECU looks up the Load to Torque Limit map (whose correct name is Torque to Load Target) and a load target is created. Just a theory.

CSR sent me a notification that you contacted them. Since I already posted in here, I told them I'd just help you out directly. Sorry I didn't reply yesterday, I've been really busy catching up from the holiday weekend. Shoot me the logs and associated maps and I'll see if there's anything jumping out at me. josh.dankel@cobbtuning.com

[boosted-M]

@cstavaru

Did you figure this out?

[cstavaru]

@cstavaru

Did you figure this out?

Not yet, but Josh@Cobb sent me a map with the Timing (Fail Safe) table being more or less identical to the Timing (Main) table. So he probably thinks the ECU enters a failsafe mode. I will have to test this out, but the big question (if it works) is why does the ECU enter failsafe mode. Are some important engine health monitors missing from the Cobb logging parameters ? Also the fail safe table timing is not so close to 0 as in my logs, so I have some doubts of this being the problem. But I will have to test it out these days.

Anyway, if you have this problem you may do the tweak above and see if it works.

[boosted-M]

Not yet, but Josh@Cobb sent me a map with the Timing (Fail Safe) table being more or less identical to the Timing (Main) table. So he probably thinks the ECU enters a failsafe mode. I will have to test this out, but the big question (if it works) is why does the ECU enter failsafe mode. Are some important engine health monitors missing from the Cobb logging parameters ? Also the fail safe table timing is not so close to 0 as in my logs, so I have some doubts of this being the problem. But I will have to test it out these days.

Anyway, if you have this problem you may do the tweak above and see if it works.

I had the "Flatline" issue but then stacked with the JB4 G5 ISO and timing recovery post shift is MUCH better.
I went back and forth with Josh earlier this year and asked if they could implement a “TIMING MODE” to view in a datalog just like they have a “FUEL MODE” to tell which fuel map the DME reading from.
I also tried copying the MAIN timing map to the FAILSAFE and this did not help me..

Hopefully you have better luck!

[cstavaru]

I had the "Flatline" issue but then stacked with the JB4 G5 ISO and timing recovery post shift is MUCH better.
I went back and forth with Josh earlier this year and asked if they could implement a “TIMING MODE” to view in a datalog just like they have a “FUEL MODE” to tell which fuel map the DME reading from.
I also tried copying the MAIN timing map to the FAILSAFE and this did not help me..

Hopefully you have better luck!

Josh@Cobb just said he also modified other tables that are not available in ATR/ATP, so it's not just the failsafe timing table. Now I'm really anxious to try the map

[boosted-M]

Josh@Cobb just said he also modified other tables that are not available in ATR/ATP, so it's not just the failsafe timing table. Now I'm really anxious to try the map

Sweet,get out there and give her hell..!!