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Relationship of TCC to shift points

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Old Apr 12, 2005 | 09:40 AM
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Question Relationship of TCC to shift points

Anyone have any tips as to how the TCC apply/release settings should be set in comparison to your shift points?

I'm about to adjust my shift points at different throttle positions and I have no clue how I should be adjusting my TCC to match (or if it even matters).
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Old Apr 12, 2005 | 09:45 AM
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they are only vs speed i would get your shift points worked out first then play with the lockup settings slightly if needed.
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Old Apr 12, 2005 | 10:31 AM
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Typically the TCC apply speed is about 2-4 MPH higher then the upshift for that gear. The release points are going to vary depending on how you want the trans to behave. I have my TCC release speeds set at 3-4 MPH above my downshift speeds for each particular gear. This causes the TCC to release first, prior to downshifting. If more pedal effort is required, then the trans will downshift to a lower gear. This has made my Camaro SS perform very nicely and accelerates quicker than OE tuned, it essentially killed all the dead spots the OE tune had.

Edit:
Adjust this table after you have fine tuned your part throttle shift points.
Also note that the 3rd gear apply speeds must be higher (can be by 1 MPH) than the 4th gear apply speeds. Otherwise you will experience the TCC lock up in 3rd, unlock and shift to 4th, then lock up in 4th again. This is bad for the TCC and it is why the OE tune is setup to lock in 3rd higher than in 4th.
Here is a screenshot of my tables:

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Old Apr 12, 2005 | 10:49 AM
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Wow this is great. Thanks!!
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Old Apr 12, 2005 | 12:16 PM
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on my car I set it such that 3rd apply is 255mph , that way the converter will only lock when in Overdrive (just a personal preference... I only wanted my car locking when I was in overdrive driving at a steady rate ... otherwise I wanted the converter to remain unlocked)
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Old Apr 14, 2005 | 12:07 AM
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Originally Posted by horist
on my car I set it such that 3rd apply is 255mph , that way the converter will only lock when in Overdrive (just a personal preference... I only wanted my car locking when I was in overdrive driving at a steady rate ... otherwise I wanted the converter to remain unlocked)
Still learning about torque converters - what are the advantages/disadvantages of locking? I've seen some people say locking is good at low speeds around town and others that raise their settings to avoid locking. Does locking just save gas at the cost of some perf?

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Old Apr 14, 2005 | 07:35 AM
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better gas mileage...its basically like having an ultra efficient 5th gear. Thats why you want to try to keep it active at some point in 4th gear so it locks up while at highway/cruise speeds...people have it stay unlocked for various reasons...sometimes big cams cause surging and you need to raise the speeds at which it locks/unlocks sometimes people just use 3rd as their cruise night gear so you can hear the exhaust more and makes you more ready for a race i guess you could say.
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Old Apr 14, 2005 | 08:16 AM
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James,

You really need to experiment with it to see what you want the car to drive like. While it's nice at times to have it lock at lower speeds, it can also cause issues like bucking. The tables I sent you have mine lock up around 40 in 3rd (I drive around town a lot in 3rd) and around 50 in 4th. Any lower in 4th was unfriendly.

I tried to get mine to lock around 35 in 3rd, but I was getting the lock/unlock/lock scenario & couldn't tune it out. Well, I probably could have, but I was growing impatient. So I raised the bar.

Other than that from what I've learned I can tell you that you don't want it to lock while shifting, so make sure that 'switch' is set to NO. And you don't want it to lock at WOT, so set the 100% TPS cell speed to your shift point in each gear. (thinking about it, it might make sense to set that cell to 2-3 mph ABOVE the shift point....hmmmmm)

Mark
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Old Apr 14, 2005 | 10:04 AM
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The "TCC Lock During Shift" option is not useable in F-bodies, I verified this with my Camaro SS. It is like the shift light option, it is there for other vehicles, not F-bodies. This feature did nothing when I turn it on and off, the TCC still would unlock during shifts. BUT on my Sierra you can notice it if it is turned off. The OE program has it turned on from the factory for assisting when pulling loads. It is very beneficial in that case.
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Old Apr 26, 2005 | 07:01 PM
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Good info, George!

If you don't mind, could you email your file so I can look at it: som2001ss@wowway.com

Bill
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Old May 16, 2005 | 08:54 AM
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Bill, sorry I just saw this thread again, but I snet you a copy of my BIN file ... if you still need it.
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