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Torque mgmt timing during coastdown?

2K views 19 replies 5 participants last post by  bluegoat06 
#1 ·
With my recent cam install, I have found that my car uses the TqMgt timing during closed throttle coastdown at low speeds, like under 25. If i keep the TqMgt reasonable like 0* the timing oscillates between 0 and something like 20* while coasting and then the car will surge when I come to a stop and it downshifts into 1st. If I increase it to 8*, then the timing is 8* during coastdown and no surging but of course the shifts are harsh and tires bark.

I do have the Idle air dialed in and it doesn't surge on idle, so that's not the issue

Why does it use TqMgt timing and not coastdown timing table? In my logs, the timing pulled due to TqMgt matches what is occurring and I have experimented by changing TqMgt so I definitely know that is what is happening. But why?

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#3 ·
That's interesting Jeremy , do you have a log ?

Can you post a print screen with your Trans TM settings ? or post your tune, or email me your tune. ?

Mine was doing that after the verter install, but it was also affecting my initial WOT punch in any gear. Tqmgt was closing down my TB upon initial WOT, fairly ****ty feeling, especially after doing a mod, i thought something was messed up :)
 
#4 ·
Email sent.
 
#5 ·
Post results, I'd like to see what the reason is too. I believe I might have something similar.
 
#6 ·
Jeremy, this is something different than what i had. Your TB is not closing like mine, your engine timing is just bouncing, just after tqmgt kicks in, i guess from CT tqmgt because your tps remains shut constant.
 
#7 ·
I'll test it on the way home by disabling all CT Downshift TqMgt
 
#8 ·
Disable the master CT tqmgt and see what happens.
 
#11 ·
Disabling CT had no effect. Tried Sport shift and it was somewhat better. I'll send a log tonight

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#12 ·
Could have something to do with the torque follower tables. I haven't changed these from stock yet.

Here's a quick log from tonight with the CT TqMgt disabled.
 

Attachments

#13 ·
In the logs she seems to do this during the 4-3 downshift, with no throttle. it's interesting that the master switch didn't do anything. If it's not CT downshift, because the master TM switch didn't do anything, then perhaps it'll be flare tgmt ?
re-enable the CT tqmgt master, and set the flare tqmgt downshift to none, dang stupid trans TM parameters we have :), hope you get it resolved.
 
#14 ·
Thanks Dario. Ill try tomorrow.

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#15 ·
Looked at the tune again last night and realized I hadn't disabled the Master CT TqMgt switch. Tried that and it seems to have solved the issue.

Here's a log from this morning.
 

Attachments

#16 ·
:thumbsup:, glad to see you nailed this down Jeremy.
Now that you have figured the issue is the CT Downshift TM, you could try to re-enable the master switch, and disabled the tip in/flare CT downshift TM (set it to none) and see if that still prevent the CT TM from causing the issue. if that doesn't do it, then put this switches back to how you have them now, and disabled the CT downshift master switch again, it's better to use the smaller TM switches first, if that doesn't do anything, then the master will be fine. don't know why would we have TM in CT, but oh well, dang stupid trans TM parameters we have :), i'm sure some of them are there for a reason.

Have fun.
 
#17 ·
I was hoping this would help me as well. My ct downshift is already disabled.
 
#18 ·
Yeah next is determine why DOD is not engaging...

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#19 ·
Bluegoat informed me that DOD doesnt function if COT is disabled.

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#20 ·
Enjoy :driving:
 
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