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TCC lockup speed?


spiderw31

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Out of curiosity more than anything else at this point, does anyone have the TCC lockup tables for a '92 LQ1/4T60E combo? I'm mainly wondering the differences between 3rd and 4th. Somehow I'm guessing RobertISaar has this info... :)

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Out of curiosity more than anything else at this point, does anyone have the TCC lockup tables for a '92 LQ1/4T60E combo? I'm mainly wondering the differences between 3rd and 4th. Somehow I'm guessing RobertISaar has this info... :)

 

there are a few more things that play into this..... but these are the major ones. notice how 3rd apply/release settings are essentially identical to 4th gear....... GM calibrators were not always so thorough. the apply/release settings for 2GS are also the same between 3rd/4th.

 

http://i.imgur.com/nJv5CtM.png

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:thumbsup: Awesome! That's exactly what I was after.

 

I'm assuming that those could be reprogrammed to lower values for 3rd gear? There's a stretch of road I frequently drive on my commute, traffic can often make it hard to keep up to the 50 mph speed limit, but staying over 40 is usually not an issue. I had the idea last night to try pulling back to D and see is the TCC would lock in that situation. Clearly, I can see why it didn't.

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It's annoying as hell how the TCC locks up at 45 but then will go as low as 41/42 before kicking out, especially when most of the main roads around here are 40MPH. Have gotten in the habit of cruising up to 45 just to get TCC lock, and then backing it down to around 42.

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that sounds like a stock 94-95 3100 calibration..... you like the shift into 4th gear around 32ish which then causes the converter to slip/stall around 2,000RPM until you hit 45? GM trans calibrator troll.

 

 

 

anyways, more relevant personal calibration: i setup the TCC to engage in 3rd at ~28, then do a shift into 4th at ~43. no more running the converter against its stall unless i'm giving it quite a bit of throttle.

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that sounds like a stock 94-95 3100 calibration..... you like the shift into 4th gear around 32ish which then causes the converter to slip/stall around 2,000RPM until you hit 45? GM trans calibrator troll.

 

 

 

anyways, more relevant personal calibration: i setup the TCC to engage in 3rd at ~28, then do a shift into 4th at ~43. no more running the converter against its stall unless i'm giving it quite a bit of throttle.

 

Yeah I really can't stand how often the converter is at stall. Makes looking at the instant mileage depressing. I'm cool with seeing low numbers when my foot is in it, but having the motor churning away and going nowhere? Stupid.

 

Now I can think of an instance when locking in 3rd may not be so nice, and that is when it makes the shift to 4th. I've felt that one by getting lockup while in drive, and then shifting up to overdrive. It's quite a thud, and maybe that's why GM tuned the way they did perhaps? I'll bet poly dog one bushings would help that a bit, but I digress...

 

I've never really given much thought to tuning / reprogramming the ECM, so I haven't really done research into what it takes. What's needed in order to change those tables?

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Now I can think of an instance when locking in 3rd may not be so nice, and that is when it makes the shift to 4th. I've felt that one by getting lockup while in drive, and then shifting up to overdrive. It's quite a thud, and maybe that's why GM tuned the way they did perhaps? I'll bet poly dog one bushings would help that a bit, but I digress...

 

consider this: the 4T60? that almost always locks in 3rd and keeps the TCC applied through the upshift to 4th.... IIRC.

 

why when the 4T60E came around GM changed that part of the valvebody, i'm not sure.

 

i still have the MC setup to do it(i don't find it excessively rough), though i've been trying to work with the VERY small amount of open PROM space left on that half of the PCM to essentially "reset" the PWM locking procedure.... i only have ~40 bytes to work with IIRC, so it isn't like i could just rewrite the whole routine. for my nAst1 trans control, i implimented it directly since i knew it could become a problem later on. since i haven't been driving the car, i obviously can't test the code in the real-world, though i could do it on the bench and guess how it would act.

 

another option is to have the TCC unlock when an upshift is about to occur, then relock after the shift happens. that has a rather strange feeling to it, feels like the clutch pack slips right before a shift(though it is only the TCC causing it).

 

the early(91-93) 4T60E trans control does have the option to ignore or allow requests to unlock the TCC due to various reasons, including impending upshifts..... those generally can be used to tweak the settings to your liking.

 

 

 

if you want to start tuning stuff on your own, small list of hardware and one piece of software will cover pretty much everything.

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