Transmission tuning?

[Reverant GTP]

Are there any good write ups on how to get our trannies dialed in? I tried a search but could not find anything. Perhaps would i be better off buying say an overkill tune and modifying from there? Im specifically looking at fluid pressures, torque converter lock up table, and torque abuse. I can handle shift point modification but am very new to this so anything else that may help would be appreciated thank you.

[91parkave]

alot of this guide helped me to understand use it as a template make small changes an keep scanning till you have it where you need it. How To: 4L60/65E trans tuning. Shifting/TCC/TM (w/ Pics) - HP Tuners Bulletin Board but first and foremost you need to keep in mind that if your transmission has a lot of miles on it or has slipping issues already etc....you may just wana hold off tuning till your transmission is in proper order.

[Reverant GTP]

Thanks alot! It does have very high miles 200k+... wouldn't changing line pressure help with keeping the trans happy? Same as torque converter lock up points? I know torque management would kill it and higher shift points wouldn't help prolong anything.

[Reverant GTP]

Well did a quick read and it sounds like nothing can beat a good old shift kit. I was just goin off of what zzp put for benefits of their pcms. So i guess my only final question is torque converter lock up tables, would they help?

[91parkave]

yea very noticeable. my min table is all 50 but my max table i varied according to temp where the normal operating temps around a 100-185degrees are set to 97 and the rest i just added to the factory values by 10. removing the tourqe managment on the transmission side wont help its life any. iyts the pressure tables and times that will help it out.

[Impala131]

Reverant, I have been making small tweaks to my transmission settings in HPT for a few months now, slowly learning by small adjustments at a time. It's actually been very rewarding. If you have a model with a performance shift button, like I do, you can have your "normal" shift table very mild, upshift earlier etc. for better gas mileage, and use the "performance" table for high-rpm shifts. We should compare notes at some point, I've still got much to learn myself.

I have had good luck making shifts more concise by decreasing the "shift time" and leaving the shift pressure alone. It gives me that nice snappy feel without the "bucking" effect.
Also, when raising (up)shift points, I try to make sure they are at least 300rpm below the rev limit. What I've found is that as the revs jump up a tad during an upshift, the car would actually cut fuel during the upshift, not good.
As far as shift times/pressures/rpm/mph goes, what I like to do is take whole tables and multiply by a reasonable percentage. For example, if I want to lower shift times, I multiply the whole table by .95 . If I want more, than I do the same thing again. I did the same thing with the torque abuse tables.
Also, I try to adjust my torque converter lock up tables in a similar manner. I try to increase the torque lockup speed along with my upshift speed, basically trying to keep a few mph between upshifting and locking the converter.

These are just my personal preferences, someone more experienced might chime in that these are not good practices. At 251k miles and original engine and tranny, I don't push it terribly hard, but have had good luck. I keep the trans in good shape with semi-frequent fluid and filter changes, and I haven't had a problem with slipping yet. The only time I've had a slipping issue is when I had the radiator out to change the condenser, which caused my trans fluid to be a bit low until I topped it off.

[Impala131]

Hmm, took a quick skim through the link 91parkave posted, I'll have to read it in greater detail. I'm not sure if CoolAid is correct about his understanding of shift point tuning. In my experience, the car seems to want to shift at either X rpm OR Y mph, while CoolAid says that the car wants both X rpm AND Y mph.

[91parkave]

on the same note when your changing those tcc apply/release tables MAKE sure your apply speeds are higher than your replease speeds and shift times should never be lower than .100

[Reverant GTP]

No performance shift here, i have a 2004 comp g. Thanks for the replies this will help when i dive into it. Im just trying to learn n help prolong things until i get a built tranny next year.

[rperry435]

Comp g has tap shift. That is considered your performance shift if I remember.

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[91parkave]

^^^ same here its all pattern x and tap up tap down

[Reverant GTP]

I was saying i dont have the performance shift button that the older ones had where the transmission did the shifting for you. Can't out shift a tranny or pcm, whatever they say. lol

[Impala131]

I was saying i dont have the performance shift button that the older ones had where the transmission did the shifting for you. Can't out shift a tranny or pcm, whatever they say. lol

Well, you'll be happy when you tune that PCM and it shifts just like you would... except more consistently.

[rperry435]

I tuned my trans using alot of parameters from the performance section of the trans. Basically saved normal settings and then performance. Then imported the performance into normal. I Did this for shift time and a few other settings I forget. Very noticable. I'm going to start tweaking settings to my personal liking with a few trips

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[rperry435]

Figured I'd ask here since it pertains to the topic.. When writing to the pcm I know it erases and rewrites...

When the battery is removed or we update them with a tech2 at work it takes a few miles before the shift points are learned.. is that the same case every time I write to the pcm?

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[Fivefingerdeathpunch]

Sorta kinda.

I know that the LTFT don't change unless you reset them, but I'm sure it may take a little bit for the PCM to relearn a few things after the re-flash. I dont think it erases everything because its only going to change stuff that you made different.

I may have no idea what I am saying here too, LOL.

[rperry435]

I thought it said erasing entire pcm. So I just figured it was.

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[rperry435]

What about tcc apply and shift speed.. the trans has to shift into 4th before tcc lockup can occur correct? I just thought it's odd the 4th apply is lower the actual 3/4shift



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[91parkave]

I can't see that being the case Because your shift points are a constant Maybe you're thinking of the fuel trims dialing In Also try bum in your tcc max /min tables by 10

Edit apply should always be higher than release always.

[rperry435]

Now I've got a p1514 calculated airflow error. ****y lol wonder what I changed to get that.. This should get interesting :beer:

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