shift timing..oh boy

[Redbowties88]

oh long story but here goes...ill try and sum up as much as possible.


step 1: got my trans built by George... he says i should run a stock TCM tune so i flash one in, only i used an 01. i didn't mind it, took FOREVER to relearn anything but other then that was fine..i liked the shifts alot they were very crisp and smooth.

step 2: winter rolled around..got tired of no ODLO and no elevated idle...so i flashed in a mostly stock version of my original OS... all i changed was i went threw the TCC apply and made it lower in the 2nd and 3rd and went through the shift timing and took the quickest shifts (whether or not it be T/H or normal) and added it to the other.. so basically i got the best f both worlds.

that was all fun and good, i also really like the part throttle part of this (05) os however i've noticed the shifts aren't quite as good. i went back into the 01 os i was running and found the shift timing was MUCH quicker in some instances.


so what i would like to know is, if i copy that timing into the 05 os im running now i should be in no danger of binding correct? as ive already run the 01 os with great success.


yea i know im crazy and overthink everything

thanks for the help everyone

 

[Redbowties88]

oh and another thing,...


does a clutch pack take longer to disengage at a lower throttle? or are the longer low throttle shifts purely for smoothness?

 

[GeneralTJI]

went through the shift timing and took the quickest shifts (whether or not it be T/H or normal) and added it to the other

I did this as well...

I also would think if you are running values that are the same as the earlier OS it should work ok? (someone else may have more info here)....

You probably already know this but there is a base shift time value, and then the modifier values (not sure how they are laid out in EFI since I use HP). Make sure you look at both to find the total value (assuming they both differ from the differet os's?)

 

[Redbowties88]

i don't know where to find the base shift

 

[GeneralTJI]

I'll could get a screen shot when I get on my tuning laptop. Then again that isn't going to do anything for you... think you would have found them if they existed for you.

(Base and Adder for each shift in both normal and t/h is how they are layed out for me IIRC.)

I'm wondering if this is an HP vs. EFI thing or because I have a 6 speed? Any EFI guys on a 6 speed see these?

 

[JoshH]

Yes

 

[Redbowties88]

Yes

to what?

sorry just a little confused

 

[TrentNell]

Shift timing is kind of a mute point to play with as the taps can and will learn around anything you set if it does not like it , I also have never had to change the factory shift timing to get good quality shifts .

 

[Redbowties88]

Shift timing is kind of a mute point to play with as the taps can and will learn around anything you set if it does not like it , I also have never had to change the factory shift timing to get good quality shifts .

as i understand it changing the shift timing is what the trans shoots for after the tap learn everything... but i could be wrong.


basically, im trying to get shifts as good as i did on that 01 os on my 05 os...possibly even better

 

[Mike_S]

I'm with Trent on this one. I've never had to do anything within the TCM other than changing shift points, never shift timing. Any poor shifts I have dealt with have always been due to poorly set defueling tables, or otherwise piss poor tuning that I have repaired second hand. The shifts on my '04 TCM tune with stock timing and a SC4 are nice smooth and crisp.

 

[MMLMM]

The shift timing value is what the trans will go to right after a reset, but then will learn to shift when it wants too..

Playing with shift timing is a very good way to cause a hang up and doesnt matter who built your trans, they will get to do it again.

 

[Redbowties88]

well i found the base timing. im an idiot it was right under my nose



mike, you say changing that shit timing wont do any good cause it will just will just learn around it but in the same breath you say it will cause a hangup?

so far ive noticed a bit of an improvement just changing up the normal and t/h tables... if it learns around it then so be it but im noticing a change

 

[SSchmi5519]

well i found the base timing. im an idiot it was right under my nose



mike, you say changing that shit timing wont do any good cause it will just will just learn around it but in the same breath you say it will cause a hangup?

so far ive noticed a bit of an improvement just changing up the normal and t/h tables... if it learns around it then so be it but im noticing a change

Before it gets a chance to adjust, you will have a tie up and a literal explosion. Hope you have a trans blanket.

 

[GeneralTJI]

I don't think this is your typical "How do I make my Allison shift fast like my turbo350??!!"... "can I 0 out my desired shift time values blah blah" topic. I think he is trying to replace some settings with other factory shift numbers from a different year/os tune. Now that may cause issues, I have no idea....

I figure if the base plus adder equal a factory number from another year tune he had previously ran it should be safe.

Maybe not worth messing with on a nice built trans though

 

[MMLMM]

well i found the base timing. im an idiot it was right under my nose



mike, you say changing that shit timing wont do any good cause it will just will just learn around it but in the same breath you say it will cause a hangup?

so far ive noticed a bit of an improvement just changing up the normal and t/h tables... if it learns around it then so be it but im noticing a change

No, I am saying that if you change your shift time, it needs time to learn, or it will use what you mess with, which can cause a hang up until it learns...Since when does it learn when you turn the key on after a reset????

And for the fact that it does learn around it, why would yo change it? So you can hurry up and go cause a tie up before it learns

You make no sense in what you are trying to accomplish. You should do some reading before you start messing with stuff.

 

[SSchmi5519]

I don't think this is your typical "How do I make my Allison shift fast like my turbo350??!!"... "can I 0 out my desired shift time values blah blah" topic. I think he is trying to replace some settings with other factory shift numbers from a different year/os tune. Now that may cause issues, I have no idea....

I figure if the base plus adder equal a factory number from another year tune he had previously ran it should be safe.

Maybe not worth messing with on a nice built trans though

As was said above it uses these values until the taps make their own decisions during the learning process. If its going to do what it wants anyway why risk it for no change?

IF you look at the base vs mod tables and do the math you can see that they are all the same except one that is only 50ms difference.

I'll take the microseconds on my ET before ill grenade my trans and possibly kill myself.

 

[MMLMM]

The trans shifts quick enough, Why do you want it to shift faster? What are you trying to gain out of a few more ms of shift time? Do you know why the shift times are set the way they are, or do you just think in your head, "hey faster shift = faster track time"??

 

[Redbowties88]

yea i know why they are what they are im not as dumb as you give me credit for....


i still think there's leeway in them.... if they were set to the absolute quickest time it takes the clutch to disengage they would all be the same given x gear...


that being said,...anyone have an answer to the second bit of my question?

 

[Redbowties88]

also, the only gear thats set differently for t/h and normal in the base setting is 5th.


being in t/h cant have an actual effect on the time it takes the clutch to disengage right?

 

[MMLMM]

yea i know why they are what they are im not as dumb as you give me credit for....


i still think there's leeway in them.... if they were set to the absolute quickest time it takes the clutch to disengage they would all be the same given x gear...


that being said,...anyone have an answer to the second bit of my question?

Then go ahead and put in the leeway that you assume it will have and have at it. I could care less if your trans explodes. Maybe we'll all get a kick out of it when George laughs in your face and reads this thread and says you were told by us and him not to run a tune when you come crying "my trans is broke, fix it". And the funny thing is once the trans re-learns, you gained nothing but a potential chance of a hang up.

And why would anyone answer the second question after you ask, we tell, and you say well, I'm smarter than you give credit for, Ill do it like this anyway. Figure #2 out on your own dude :thumb: