6AT Post shift timing corrections - lets end this.

RSL

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That last log wasn't as bad and pre/post shift loads were closer together, so may give some weight to the closer the better. I know AT AWDs are extremely picky about torque output to avoid corrections on shifts and they are usually sub-700nm max (maybe 650-700). AT RWD aren't as bad, but you may just need to dial yours in. You can try some quick tests to see if reducing your torque output pre/post shift and/or getting them closer together helps at all. Quickest way to drop overall torque output would be to increase the load break points (in the 160-max loads for now) by say 5-10 at a time, log torque output and corrections and repeat with another 5-10 if needed. If you see slippage anywhere in the logs though, stop and move tq output back up.

Someone looked at the timing ramp rates post-shift (brad I think), but not sure if anything came of it. If Jake Y is adding them to the XDFs though, they may have some merit.

I've never run any OTS MHD maps, so can't say, but I thought they knocked that desensitized crap off after some version. On 93 and 20+psi on hybrids, I almost always have a least 1 correction and I'd rather see them and know it's doing it's job. Look at stock bin logs some time, even or especially at cruise...corrections galore. Timing corrections are keeping things safe, so while no one likes seeing them, better to have them than need them and not have them ;)
 

all4bspinnin

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Jun 12, 2017
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That last log wasn't as bad and pre/post shift loads were closer together, so may give some weight to the closer the better. I know AT AWDs are extremely picky about torque output to avoid corrections on shifts and they are usually sub-700nm max (maybe 650-700). AT RWD aren't as bad, but you may just need to dial yours in. You can try some quick tests to see if reducing your torque output pre/post shift and/or getting them closer together helps at all. Quickest way to drop overall torque output would be to increase the load break points (in the 160-max loads for now) by say 5-10 at a time, log torque output and corrections and repeat with another 5-10 if needed. If you see slippage anywhere in the logs though, stop and move tq output back up.

So youre saying to keep the load actual close to the same pre/post shift?

When you say to reduce overall torque output, youre referring to lowering the appropriate cells in load to torque 1-3?
 

RSL

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Aug 11, 2017
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So youre saying to keep the load actual close to the same pre/post shift?

When you say to reduce overall torque output, youre referring to lowering the appropriate cells in load to torque 1-3?
Yes on keeping loads closer together before/after shifts. The thought there is many tables are load based and 20 load/1500rpm difference pre/post shift could be widely different values, causing things to act up. Based on the log, shifting by 5500rpm should maintain load in the 190s (likely not jumping columns in load axis tables) and only change RPM. If the corrections remain or disappear, you’ll have a better idea where to focus. If they don’t go away, will need to dig further and that first step would probably be torque output.

I wouldn’t reduce the z-cells individually in L2Ts right now, I’d just increase the load break points themselves. That will maintain the Nm/RPM curve currently in the tables, but will reduce the output at current actual loads. So, if actual load is 170 and you move up the L2T load break points, 170 actual will then fall in a lower value rows and reduce tq output. I'd only move the break in the last 2 rows, maybe 3 if needed, since we're only looking at WOT. Don't mess with loads you're hitting for normal part-throttle driving.
 

all4bspinnin

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shifting at 5500 had no effect. Corrections were still there. im testing the torque modifications now. I'll keep you guys posted.
 

bradsm87

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Dec 15, 2016
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I've been out of the game for around 7 months but I finally have my diff back and will be doing more testing soon once the diff is in.

I think the answer is slightly delaying the re-introduction of torque (which means ignition timing when it's a petrol engine) post-shift. It's easy to see in logs that this is happening before the shift is even finished. When xHP very first said they'll be introducing TCU flashing and asked for features, this is the first thing I said but I still don't think xHP have shown much interest in working on this.

As soon as my car is going, I'll be doing further work in discovering the tables for both rate or torque re-introduction and also the point at which it starts re-introducing torque.
 

all4bspinnin

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Id like to see Jeff's log on non desensitized knock tables. I would be curious to see the difference.

Jeff, youre wgdc is pretty high overall. Some inlets/outlets should help lower it a bit.
 

all4bspinnin

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Brad, how can I help with the torque re-introduction via the TCU? I'd like to help you with research and digging through the BIN file.
 

bradsm87

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Brad, how can I help with the torque re-introduction via the TCU? I'd like to help you with research and digging through the BIN file.

I'm still way out of the game. I'll have to put the diff in, run the bad fuel out, catch up with a few other urgent things on my to-do list then get back in to the TCU table discovery in a couple of weeks. Not long now.

In the meantime, I'd highly recommend to ask XHP for more delay before torque re-introduction after intervention. Honestly, if they sort out these couple of remaining things in the Stage 3 OTS, I'd be tempted to just run that myself and save myself a lot of tuning time.
 
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Jeffman

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Id like to see Jeff's log on non desensitized knock tables. I would be curious to see the difference.

Jeff, youre wgdc is pretty high overall. Some inlets/outlets should help lower it a bit.
I purchased RB Inlets...they're still in the box lol. No time to install on my xi. Thought about having VAC do it with some other suspension upgrades while the subframe is down but that got way too expensive.
 

all4bspinnin

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Its worth it for sure. I havent mentioned this here, but im having custom metal high flow outlets created. Im waiting on the machine shop prices but i have a production run of 5 that will be made. I'll post more info when i get closer. Maybe you could run one. It will definitely lower your wgdc.
 

Jeffman

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Looks pretty good but if torque re-introduction point and rate was slightly slowed, that increase in RPM at the end of the shift would go away and be a lot better on the clutches.
Agreed, Brad.
Interesting that I got the exact same effect using the Alpina flash I had reported 6-12 months ago on bummerboost. (And coincidentally, you also commented on the same thing about my rpm blip during shift and it not being good for the clutches.) :)
I switched from Alpina to xHP for faster, firmer, DCT-like shifts. So there's a trade-off here.

[Edit: interesting alternative spelling fact-checker fake news subroutine built into this forum... I typed "B i m m e r b o o s t" and it's really what I typed and see it in my edit screen, but it gets converted to bummerboost. Cool.]
 
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all4bspinnin

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You guys need to contact Trebila. When he tuned my stock turbo AT he completely eliminated post shift timing corrections.

Are you stacked on Jb4? I've read every post he's made talking about it. He's said both vanos and fueling. I've tried both... its not the case. Most people desensitize knock sensors or stack with jb4 (not a fan of this)


edit: after some research it does appear that trebila does lower knock sensitivity as well. http://www.n54tech.com/forums/showpost.php?p=403976&postcount=39
 
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Cheezy

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I have this issue and i was super concerned with it. Im not tuning expert by any means so i changed all the typical hardware, coils, plugs, injectors, walnut blast. It didnt help any. I was working with David Shoup having him review my logs, but we never made any changes. He said a car local to him was having the same issue and being a PITA. Ive since developed a misfire anytime I cross 6000rpm in 4th gear. Only then, and only in cyl6. I have a feeling this is something tune related or trans tune related, and eventually when we find it we'll be able to tune it out. Until the misfire is gone, the timing issue will have to wait, that is unless they're related in cause.
 

bradsm87

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Dec 15, 2016
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You guys need to contact Trebila. When he tuned my stock turbo AT he completely eliminated post shift timing corrections.

There are things you can do in the DME tune to help and compromised things you can do in the DME tune to completely eliminate it but the BEST way will be to slightly delay the re-introduction of torque requested by the TCU.
 

all4bspinnin

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I have this issue and i was super concerned with it. Im not tuning expert by any means so i changed all the typical hardware, coils, plugs, injectors, walnut blast. It didnt help any. I was working with David Shoup having him review my logs, but we never made any changes. He said a car local to him was having the same issue and being a PITA. Ive since developed a misfire anytime I cross 6000rpm in 4th gear. Only then, and only in cyl6. I have a feeling this is something tune related or trans tune related, and eventually when we find it we'll be able to tune it out. Until the misfire is gone, the timing issue will have to wait, that is unless they're related in cause.

Cheezy, what gap are you running on your plugs?