6AT Post shift timing corrections - lets end this.

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all4bspinnin

Corporal
Jun 12, 2017
140
I'd like to call on all that have had any success eliminating post shift correction. Id like to get everyones opinion and start talking about what people are doing to eliminate this.

Some of these 6at cars are ok but every now and then, you get one thats an absolute bear.

Case: http://datazap.me/u/all4bspinnin/ruben-13-original-vanos-stage-3-trans-flash?log=1&data=3-7-9-10-11-12-13-14-25-28-29-31&zoom=19-67

http://datazap.me/u/all4bspinnin/ruben-14?log=0&data=3-9-10-11-12-13-14-25-28-29-31&zoom=41-89

So this is an ije0s 135i. 6at with with fbo (inlets, no outlets) downpipes plumbed to a single 3.5 inch exhaust. Car is well maintained with new plugs, coils, and walnut blast. The gas where the car fills up has tested to be good e85.

I've tried every combination of vanos, fueling, low boost, low/high timing. The car will pull a perfect 3rd gear log but the second you shift, things go to hell.

For testing, I tried an mhd e60 map and it pulled -3 on every cylinder (less boost and less timing).

Any suggestions would be greatly appreciated.
 

hassan_hamdan

Specialist
Aug 1, 2017
74
I cant seem to open either link on my pc, nor android, try reposting,

my suggestion would be to look at the load, o2 sensors, and try running data logs at different gears to see if there is any other corrections happening at WOT.

When you say "things go to hell" on 4th what do you mean by that exactly?
 

all4bspinnin

Corporal
Jun 12, 2017
140
I cant seem to open either link on my pc, nor android, try reposting,

my suggestion would be to look at the load, o2 sensors, and try running data logs at different gears to see if there is any other corrections happening at WOT.

When you say "things go to hell" on 4th what do you mean by that exactly?
weird...datazap isnt working for some reason. anyone else having trouble?

Whats happening is during a 2nd, 3rd gear, or 4th gear pull (without shifting) the logs are clean. No WOT correction. However, when the car shifts it see's heavy timing corrections (ie things go to hell).

When you say look at the load what are you referring to? The load stays back of target like it should. 02 sensors are new.

Have you successfully tuned this issue out?
 

hassan_hamdan

Specialist
Aug 1, 2017
74
weird...datazap isnt working for some reason. anyone else having trouble?

Whats happening is during a 2nd, 3rd gear, or 4th gear pull (without shifting) the logs are clean. No WOT correction. However, when the car shifts it see's heavy timing corrections (ie things go to hell).

When you say look at the load what are you referring to? The load stays back of target like it should. 02 sensors are new.

Have you successfully tuned this issue out?
Interesting, the reason im wondering is if the ecu is picking up the change in load, when the car shifts gears or if is not and feels the shift in gears as a "in neutral" so to speak, similar to when you press the clutch to change gears, if its thinking that when your shifting gears that the load is dropped suddenly and hence pulling back timing like crazy.

I had a friend who had a similar issue before where something was adjusting and timing was pulled back, cause was from a crack in the downpipe, which after solved his issue.
 

all4bspinnin

Corporal
Jun 12, 2017
140
Interesting, the reason im wondering is if the ecu is picking up the change in load, when the car shifts gears or if is not and feels the shift in gears as a "in neutral" so to speak, similar to when you press the clutch to change gears, if its thinking that when your shifting gears that the load is dropped suddenly and hence pulling back timing like crazy.

I had a friend who had a similar issue before where something was adjusting and timing was pulled back, cause was from a crack in the downpipe, which after solved his issue.
Timing drops during shift then recovers as it hits the next gear. Back when I was on Cobb AP using ATR, you could enable live tracing and that would allow you to see which cells you dropped down to during a shift. Sadly, with MHD I lost that capability. I know that it does drop to around 150 according to the datalogs but I think it may drop even lower for a split second and the logs do not pick it up as the sampling rate isnt fast enough to catch it... i could be wrong on that though. Whats interesting is if you look at the stock timing on say a 335is you can see how they have lowered timing in the areas where the car shifts.

I am personally of the opinion that timing is reintroduced a fraction of a second too quickly on the 6at cars. Sadly, I do not have any way to alter those tables in the ecu. Jake Y with MHD supposedly has a fix for this in the works but its still up in the air as to its release.
 

hassan_hamdan

Specialist
Aug 1, 2017
74
Timing drops during shift then recovers as it hits the next gear. Back when I was on Cobb AP using ATR, you could enable live tracing and that would allow you to see which cells you dropped down to during a shift. Sadly, with MHD I lost that capability. I know that it does drop to around 150 according to the datalogs but I think it may drop even lower for a split second and the logs do not pick it up as the sampling rate isnt fast enough to catch it... i could be wrong on that though. Whats interesting is if you look at the stock timing on say a 335is you can see how they have lowered timing in the areas where the car shifts.

I am personally of the opinion that timing is reintroduced a fraction of a second too quickly on the 6at cars. Sadly, I do not have any way to alter those tables in the ecu. Jake Y with MHD supposedly has a fix for this in the works but its still up in the air as to its release.
And this is one of the reasons why some people stack MHD with JB4 to allow you to get those types of logs.
Coming from a speed6 I know the cobb tuning and the ability to capture the live tracing. Again you get what you pay for haha,

I am crurious to see what Jake Y says about the issue.
 

all4bspinnin

Corporal
Jun 12, 2017
140
Datazap.me should be back up and running today if you wanted to look at the logs.

has anyone here had success with removing has anyone here had success with removing the shift Corrections
 

all4bspinnin

Corporal
Jun 12, 2017
140
Here you go. This forum doesn't allow us to upload *.bin files so I changed the extension to *.txt
Make sure to save it as *.bin

Good luck, and let me know how you make out.
Thank you for posting that. Which torque tables are you referring to specifically? Im comparing it with the bin i was using and im trying to see whats different. Load to torque looks the same. Im going to spend some time and dig though it.
 

Jeffman

Captain
Jan 7, 2017
1,340
LTT tables, I think. I could be wrong. @RSL and Jake Y have a firmer grasp of all the Torque tables. You'll see that this one uses the standard WGDC logic unlike the other bin I posted a few weeks ago which uses the simpler WGDC (RPM x Boost Set Point) logic.
 

all4bspinnin

Corporal
Jun 12, 2017
140
So after looking this over for a few i realized this was based on the old SPX mapping. If you look, you'll see the knock tables have been desensitized :(
 

Jeffman

Captain
Jan 7, 2017
1,340
A) Yes, I got an earlier version from spxxx.
B) Are you sure the knock tables are desensitized? I certainly do have timing corrections occasionally. But if you're correct ... Holy S&@t! I've been driving for the last two years on various tunes, some E50, many 93 oct, pushing 20-25 psi boost on shock turbos with no big issues (knock wood)!
 

all4bspinnin

Corporal
Jun 12, 2017
140
Yes, these tables are 100% desensitized.... The bottom pic is stock. You may want to check your current tune and make sure youre not running those same numbers. Sorry to scare ya jeff. lol
 

Attachments

Jeffman

Captain
Jan 7, 2017
1,340
Well look at that! My spark retard intensities are adjusted down, just a tad...
Again, never seemed to cause me any trouble for the last few years.
 

RSL

Sergeant
Aug 11, 2017
395
I don't have many issues with it on DCT, but also have enough problems just finding room to log through the top of 3rd out here, so it's not something I've spent a lot of time with, especially in higher gears. I'm on 93 and not running nearly those timing requests either. Definitely want to log torque limit active and torque output though. Torque and load do seem to be recurring themes in shift-related timing issues, so I'd start there.

All4bspinnin, try shifting earlier, say 5500-6000rpm or not long after load (boost) starts falling off. Your before/after shift loads and other things (remember, everything is load based) should be closer together and might yield some indication. As for why it only happens on some gears and not others, obviously, actual loads on the car are different, but there are also many shift-related tables in the bins and some are gear specific.
 

all4bspinnin

Corporal
Jun 12, 2017
140
Ross, glad to know I was thinking along the same lines. Ive actually logged torque request and torque limit active. During shift the torque limit never showed up. If i recall, torque was over 700. Ive heard that people have had limited success adjusting the load to torque tables either up or down in the problem rpm. Have you tried this?

Shifting around 6k does the same thing sadly. But i'll give it another try today.

This was a log on the same tune, except I let off during shift. No corrections except for one -3. I think this is something Jake is going to have to release in the next update. I think timing is just being re-introduced too quickly.
http://www.datazap.me/u/all4bspinnin/ruben-15-full-throttle-shift-vs-list-shift?log=0&data=3-23


 
Last edited:

all4bspinnin

Corporal
Jun 12, 2017
140
What really has me concerned is that people are just driving around like this. I logged this same car on mhd e60 and it pulled timing on every cylinder during the shift. Although not as much due to lesser timing and boost. I also think MHD e60 has slightly desensitized knock sensors. I was reading a thread from bummerboost talking about it a while ago.

For a while i was thinking it was octane related but ive tried multiple stations that tested to be true.
 

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