PCM Diagnostics & Tuning HP Tuners | Holley | Diablo

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Old Jan 1, 2004 | 03:44 PM
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From: Deer Park Tx
Default line pressure

i have a transgo shift kit with a TCI servo and my shifts are way to hard. barking tires at 1/4 throttle.
my max line pressure is at 90 on my edit.
what do i need to do to soften up my shifts so i donot blow this trans up?
the guy who built the trans says that if he turns down the EPC any more it will be at the stock setting. sorry if this is a repeat but i did not find anything in the search section that would help me. any info will be greatly appreciated

P.S. detailed instructions would also be appreciated .
Thanks,
Daniel
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Old Jan 1, 2004 | 04:53 PM
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Originally Posted by 01 Thunder
i have a transgo shift kit with a TCI servo and my shifts are way to hard. barking tires at 1/4 throttle.
my max line pressure is at 90 on my edit.
what do i need to do to soften up my shifts so i donot blow this trans up?
the guy who built the trans says that if he turns down the EPC any more it will be at the stock setting. sorry if this is a repeat but i did not find anything in the search section that would help me. any info will be greatly appreciated

P.S. detailed instructions would also be appreciated .
Thanks,
Daniel
What's wrong with stock settings? Mine is at stock settings and gets rubber at Wot shifts.
The Transgo is supposed to firm the shifts without changing PCM settings.
How many shims were installed?
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Old Jan 1, 2004 | 05:26 PM
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there are no washers and double springs but its shifting way to hard. i pretty sure my line pressure has be moved up to high. i just got a tune through the email and it got way to hard but i cant get a hold of the guy that did my tune to correct for it. so im trying to fix it my self before i blow up the trans. im having to take off in 2 so i dont hit 2 to hard when it shifts.
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Old Jan 1, 2004 | 05:37 PM
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Originally Posted by 01 Thunder
there are no washers and double springs but its shifting way to hard. i pretty sure my line pressure has be moved up to high. i just got a tune through the email and it got way to hard but i cant get a hold of the guy that did my tune to correct for it. so im trying to fix it my self before i blow up the trans. im having to take off in 2 so i dont hit 2 to hard when it shifts.
Put the stock settings back for Positive Pressure. Also Base Pressure vs Torque(I just found out about it's affect). Make the changes you want slowly.
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Old Jan 1, 2004 | 05:55 PM
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what effects are there with the Base pressure vs. torque? i am still trying to learn this complex system.
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Old Jan 1, 2004 | 06:10 PM
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Originally Posted by 01 Thunder
what effects are there with the Base pressure vs. torque? i am still trying to learn this complex system.

https://ls1tech.com/forums/automatic-transmission/114376-line-pressure-discussion-when-too-much.html

go to post #16
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Old Jan 1, 2004 | 06:26 PM
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ok i understand what they are talking about but, im not that welled schooled on this. i noticed that in my pos. pres. vs. temp that i had a diffrence of about 78 in row 84. that was the highst diffrence between the stock tune and this most recent tune. the lowest was a -20 at row 96. how can i copy the original table and put it in this new one?
Thanks again for your info,
Daniel
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Old Jan 1, 2004 | 07:08 PM
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Originally Posted by 01 Thunder
ok i understand what they are talking about but, im not that welled schooled on this. i noticed that in my pos. pres. vs. temp that i had a diffrence of about 78 in row 84. that was the highst diffrence between the stock tune and this most recent tune. the lowest was a -20 at row 96. how can i copy the original table and put it in this new one?
Thanks again for your info,
Daniel
Do you have EDIT? If so, open the file that you're using and open the stock file in the the "read file". Use Copy Table selection to transfer the values.
Do the same for Positive pressure table.
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Old Jan 1, 2004 | 07:19 PM
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yeah i have edit and i just figured that out i was able to put my stock pos. press. vs. temp table back into it. will this soften it up a bit?
i have been playing with it for a couple of hours now and i am fixen to go and load it onto the pcm. see if it works.
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Old Jan 1, 2004 | 07:41 PM
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Originally Posted by 01 Thunder
yeah i have edit and i just figured that out i was able to put my stock pos. press. vs. temp table back into it. will this soften it up a bit?
i have been playing with it for a couple of hours now and i am fixen to go and load it onto the pcm. see if it works.
Based on the changes you mention, I would think so. Were there any changes to the Base pressure vs. torque table?
Let use know the results.
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Old Jan 1, 2004 | 08:22 PM
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no there wasnt seemed to be the same. but i will double check. i just got through chatting with Wait4me on LS1TUNE.com and he looked at my tune and said it was the tune killing the trans. said he fixed it where it wont. ill let yall know.
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Old Jan 1, 2004 | 08:53 PM
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I am kinda having the same problem. I just rebuilt my trans with the TCI rebuild kit which came with a TCI shift kit and my 2nd to 3rd shift is really hard. It kinda bothers me so i was wondering is there any way to lower my line pressure without spending $500 on LS1 Edit? Thanks
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Old Jan 2, 2004 | 07:03 AM
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Confer with redLS1 Z28. Is a mechanical solution, rather than a computer solution possible?

Since my Raptor rebuild kit was installed (which included a 2600 stall torque converter) additional information has been posted on the vendor's web site:

"All 1998 ups have a Torque Management System that picks up the higher stall speed and firmer shifts. When this happens the computer thinks there's a problem and turns the pressure down. Then it detects a slip and turns the pressure up too high and blows the end out of the clutch drum. This problem is corrected with the use of the Predator."

They recommend the Predator to correct the problem, but this seems an expensive solution. Does anyone have an alternative??
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Old Jan 2, 2004 | 10:32 AM
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The adaptation time might be increased to mellow out the
hard bang. Much of what shift kits do (from looking at the
stuff that came with my Trans-Go) seems oriented at
making the gear change cycle faster, relieving bleed-
down and feed orifices. The speed of shift, rather than
the pressure-once-shifted, is what makes the bark -
coupling the engine "flywheel mass" suddenly to a
lower numerical ratio, and flashing into the converter's
torque multiplication region. A slightly slower shift apply
will let this happen more smoothly. A clutch wear /
hard breakage lifetime tradeoff is in there somewhere.

What you see as line pressure I believe is just the
commanded duty cycle and not true line pressure.
That should be gauge-checked soon, just to put your
mind (and possibly the tranny) at ease. Everything
downstream from the hard regulator is soft settings.
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