TCC Problems (3.69 gears)

[Andy0x1]

Short ver:
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Torque Converter almost never goes into lockup mode, instead it just "thinks about it"

Converter was made by Edge Racing

Transmission has 3.69 gear's

VSS Pulses per mile: 23430 (left alone)
Rev - Trans: 9.1172 (left alone)

Drive Sproket Ratio: 0.892 (scaled down from 1.121)
Trans Revolutions/Mile: 2568.3983 (left alone)

Other then the TCC issues, everything else works fine, spedo is accurate, etc...



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Details:
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I can't even remember far back enough as to when the TCC actually worked properly.

It seems to have a mind of its own on if it will lockup or not, many times it will just pulse on for a 1/2 second then remain off...

If you data log it, it looks like it goes from 0's to -'s like it's in deep thought, but never actually begins to even try to establishes a lock.

Thinking I may need to change my max / min settings, I rasied it to 100max 99min, and gave that a try...

TCC will enable for about 1/2 sec and make the car jerk then back off, for a sec or so, then back on, - feels like a moron driving a manual trans car.

I guess I expected it to be stiff, but not to toggle lock / unlock.

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Makes me think there is another variable such that I just don't have access to re-program such as an Abuse mode, or torque calculation.

Any thoughts?

[Andy0x1]

Here's an example log of the the TCC letting go for no apparent reason.

Time / RPM / MPH / TPS / KR / TCC Duty / TCC Apply time / TCC Slip RPM
59:21.2 1668 23 8 0 0 0 258.8
59:21.3 1668 24 8 0 0 0 254.8
59:21.4 1664 24 9 0 0 0 250.2
59:21.5 1678 24 9 0 0 0 249.2
59:21.6 1685 23 9 0 0 0 250.5
59:21.7 1689 24 9 0 0 0 254
59:21.8 1696 23 9 0 0 0 256.8
59:21.9 1696 24 9 0 0 0 258.2
59:22.0 1698 24 9 0 20.4 0 254.2
59:22.1 1700 24 11 0 20.8 0.2 246
59:22.2 1736 24 11 0 21.6 0.2 247
59:22.3 1750 24 11 0 21.6 0.4 263
59:22.4 1748 24 12 0 22 0.4 274.5
59:22.5 1750 24 11 0 22.4 0.6 273.5
59:22.6 1734 24 12 0 22.4 0.6 265.5
59:22.7 1711 24 13 0 22.7 0.8 251
59:22.8 1683 24 13 0 23.1 0.8 233.2
59:22.9 1672 25 13 0 23.5 1 209.2
59:23.0 1655 25 13 0 23.9 1 187
59:23.1 1641 25 13 0 24.3 1.2 160.5
59:23.2 1657 25 14 0 24.3 1.2 143.5
59:23.3 1687 25 14 0 24.3 1.4 140.5
59:23.4 1709 25 14 0 24.7 1.4 150.2
59:23.5 1727 25 14 0 25.1 1.6 154
59:23.6 1729 25 14 0 25.1 1.6 158
59:23.7 1729 26 14 0 25.5 1.8 157.5
59:23.8 1720 25 14 0 25.5 1.8 154.2
59:23.9 1720 26 14 0 25.9 2 150
59:24.0 1727 26 14 0 25.9 2 142.5
59:24.1 1716 26 14 0 26.3 2.2 131.8
59:24.2 1711 26 14 0 26.3 2.2 119.5
59:24.3 1716 27 14 0 26.3 2.4 109
59:24.4 1727 27 14 0 26.3 2.4 104
59:24.5 1722 27 14 0 26.3 2.6 98.2
59:24.6 1731 27 14 0 26.7 2.6 92.2
59:24.7 1731 27 14 0 26.7 2.8 85.8
59:24.8 1729 27 14 0 26.7 2.8 78.8
59:24.9 1724 27 14 0 27.1 3 70
59:25.0 1738 27 14 0 27.1 3 63
59:25.1 1743 28 14 0 27.1 3 57.2
59:25.2 1736 28 14 0 27.1 3 49.5
59:25.3 1736 29 14 0 27.1 3 41
59:25.4 1740 29 14 0 27.1 3 34.5
59:25.5 1754 29 14 0 27.1 3 32.5
59:25.6 1743 28 14 0 27.1 3 31
59:25.7 1745 28 14 0 27.1 3 22.8
59:25.8 1757 29 14 0 27.1 3 15.2
59:25.9 1769 29 14 0 27.1 3 14.8
59:26.0 1776 29 14 0 26.7 3 14.8
59:26.1 1780 29 14 0 27.1 3 12.8
59:26.2 1780 29 14 0 27.1 3 9.2
59:26.3 1780 29 14 0 26.7 3 6.2
59:26.4 1771 29 14 0 26.7 3 -1.8
59:26.5 1783 29 14 0 26.7 3 -8
59:26.6 1795 30 14 0 26.3 3 -11.5
59:26.7 1793 30 14 0 26.3 3 -13
59:26.8 1798 30 14 0 26.3 3 -17
59:26.9 1851 30 14 0 0 3 -8.8
59:27.0 1979 30 14 0 0 3 33
59:27.1 2037 30 14 0 20.4 0 92.5
59:27.2 2037 30 14 0 20.4 0.1 132.8
59:27.3 2021 30 14 0 20.4 0.2 150.8
59:27.4 2000 30 13 0 20.8 0.3 151.5
59:27.5 1988 30 13 0 20.4 0.4 145.2
59:27.6 1964 30 12 0 20.4 0.5 128.5
59:27.7 1946 30 12 0 20.4 0.6 108
59:27.8 1932 31 12 0 20.8 0.7 88.2
59:27.9 1929 31 12 0 20.8 0.8 69.5
59:28.0 1907 31 11 0 20.8 0.9 49.2
59:28.1 1877 31 10 0 20.8 0.9 24.8
59:28.2 1843 31 9 0 20.4 0.9 -4.8
59:28.3 1818 31 9 0 20.4 0.9 -34.8
59:28.4 1828 32 8 0 0 0.9 -58.2
59:28.5 1846 31 8 0 0 0.9 -65
59:28.6 1854 32 8 0 0 0.9 -62.8
59:28.7 1846 31 8 0 0 0.9 -63.5

[Russ K]

Return all speedo fields, trans shift speeds & TCC lock up speed tables back to stock. Then enter 4.14 for the new gear ratio and leave the stock 1.121 sprocket ratio, then hit the commit button. So 4.14/1.121=3.693.

Russ Kemp

[Andy0x1]

This would keep the VSS Pulses per Mile the same (23430)
but Decrease the Rev - Trans from 9.1172 to 7.2491
Drive Sproket Ratio (1.121) -same-
Trans Revolutions/Mile will jump from 2568.3983 to 3231.5037

Does that sound right?

I ask because if I compare the stock GTP bin, to a GT bin, (which has 3.29's v.s. 2.93's) and the only difference is the Drive sproket Ratio of 1.121 v.s. 1.000

-A

[Andy0x1]

Why would for example the VSS Pulses/Rev: (This is the number of pulses received from the VSS sensor per output shaft revolution) decrease with deeper gears?

Deeper gears would obviously reduce the output shaft revolutions per input revolution, but the VSS Pulses/Rev on that output shaft would be unchanged.

i.e. 1 output shaft revolution will still push the car x distance regardless of gearing.

Input would be a different story. Hence I only changed the Drive Sproket Ratio (from 1.121 to 0.892)

GTP 2.93's (1.121)
GT 3.29's (1.000)
3.69's = (x.xxx)

1.121/0.892*2.93=~3.68
-or-
1.000/0.892*3.29=~3.69

[Andy0x1]

I did some additional logging, and have an idea as to what the problem may be....

The TCC needs to see positive TCC Slip values to engage....

Shortly after engaging the slip values go negative.

They shouldn't be going negative - they must not be calculating correctly.


Duty Cycle / TCC Slip
0 222.5
23.1 221.5
23.1 221.5
23.5 217.2
23.5 207.5
23.9 156.8
24.3 34
24.7 -96.5
0 -173.5
0 -154.5
0 -75.8
0 18
0 97
23.1 137.8
23.1 161
23.1 174.5
23.5 169.8
23.9 98.2
24.3 -22
24.7 -131.5
0 -171.2
0 -116
0 -31
0 52.2
22.7 108.8
23.1 143
23.1 162
23.1 166.8
23.5 137
23.9 42.5
24.3 -77.5
0 -164.2
0 -156.8
0 -83

[Andy0x1]

Return all speedo fields, trans shift speeds & TCC lock up speed tables back to stock. Then enter 4.14 for the new gear ratio and leave the stock 1.121 sprocket ratio, then hit the commit button. So 4.14/1.121=3.693.

Russ Kemp

OK so your right, that fixed it!

Thank you!

(Note: I didn't have to re-adjust any of the shift speed tables etc, as the 1.121 / 0.892 - VSS Pulses per rev / Trans Output rev per mile cancled eachother out.)

I

[3800 cavalier]

russ can you explain why the change is done this way please. i have an issue close to this. i changed the stock gtp drive chain to the gmr 1" chain. its 35 teeth driven and drive sprocket. so a 1.0 ratio. i changed the same feild for drive sprocket ratio from the stock setting to 1.0 then had shifting issues. it would not shift when it wanted to and the incorrect gear ratio came up and set limp home mode. ill try this with the same logic you used but just curious as to why its done like this. thanks

[Bandit gs]

^^Set them back to stock and enter a gear of 3.69, enter, that should get it close. Monitor your pulses per mile in 3rd gear, command third. If it reads anything but 1.00 then tweak the 3.69 (higher or lower) to get the pulses to read 1.00 in 3rd

I went though a transmission trying to figure out how to tune a gear swap, nobody anywhere new how to do it. What Russ said above is what works, you can do it other ways but it really is a hassle. I chased a TC lockup issue for a year, swapping hardparts and nothing fixed it, in the end I figured out the numbers were wrong.

[3800 cavalier]

see my other gear ratio post with an update.