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ATT or Heath reflash

Brooklyn Tow said:
127 MPH in 2nd gear?
Click to expand...

In other words, 2nd doesn't lock up ... under stock programming. Most of the time, you don't want 2nd locking up at all. There is a lot of torque/inertia happening with a truck moving that slow, and a sudden shift can break transmission shafts.
 
Matt Bachand said:
I notice Hank has TCC LOckup 2nd gear in his sig... wassupwitdat?
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When I got my PCM reflashed from Lyndon at westers I had him do it. I had to return it 3 times to get it right, he was great to work with, since I was the first to request this it was a trial and error.

The problem was what speed to tell the pcm to lock up. To get it right the magic number was 21 mph, it would lock and stay.

Man what a difference before it would slip(and hardly go anywere), now she pulls strong all the way through
 
HANK1948 said:
When I got my PCM reflashed from Lyndon at westers I had him do it. I had to return it 3 times to get it right, he was great to work with, since I was the first to request this it was a trial and error.

The problem was what speed to tell the pcm to lock up. To get it right the magic number was 21 mph, it would lock and stay.

Man what a difference before it would slip(and hardly go anywere), now she pulls strong all the way through
Click to expand...

Do you tow really heavy, or does this help in all unloaded driving too? Or do you drive often leaving shifter in '2nd'? Just curious why other modders don't play with this. Or perhaps, now they will.
 
Matt Bachand said:
Do you tow really heavy, or does this help in all unloaded driving too? Or do you drive often leaving shifter in '2nd'? Just curious why other modders don't play with this. Or perhaps, now they will.
Click to expand...

Like I said (above), you can break things locked-up in 2nd. Those of us with manual TCC lock know how hard it can shift (2-3) when locked... after the first time, I never lock it in 2 unless I manage the shifts myself so the load is off before shifting.
 
buddy said:
If controlled by the PCM rather than overriding the control it may shift appropriately.
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Yep, that's quite possible... there is a ton of torque/inertia in that equation at lower speeds, though. That's why GM didn't lock it in the first place, according to guys like Bill and gmctd. Seeing the effects of a locked TCC and a fast shift convinced me, but anything is worth a try.

What's the worst that can happen? Somebody shatters an input shaft? That can be replaced, too.

There's a lot of stuff we do routinely that Gm didn't do for fear of breaking things; that's the difference between enthusiasts who don't mind fixing their issues when they get near the edge of the envelope, and manufacturers who want to guarantee that things will stand up to most normal abuse... sort of like saying 'yeah, you can put 20+psi boost into your engine'... most of us know how long that will last, so we're OK with it - but telling a rookie to go ahead and weld their wastegate shut is not a good idea. :D
 
As the PCM handles my shifting, it never shifts into a gear locked up, even downshifting doing 55 out of overdrive, it shifts into 3rd at 2500, then locks up resulting in 2200 or so. Never does it engage into gear already locked. (I wish it did)... But that's probably why it doesn't.
 
When I recalibrate my vss could I make it so the computer would think I was goin slower than I really am so my converter locks up around 40 or would that screw things up. Rite now mine doenst lock up til around 52 with my 33's so rite now I dont have any giddy up when it locks up. It drops under 1500 rpm I think it runs rite around 1500 at 55.
 
6.5coalroller said:
When I recalibrate my vss could I make it so the computer would think I was goin slower than I really am so my converter locks up around 40 or would that screw things up. Rite now mine doenst lock up til around 52 with my 33's so rite now I dont have any giddy up when it locks up. It drops under 1500 rpm I think it runs rite around 1500 at 55.
Click to expand...

You would have to make it think you're going faster. Problem is it would effect shift points too, may make you bog really early, not sure.

Aren't you OBD1? If so just do the TCC lockup mod! I'm envious of this mod as I'm obd2.
 
Yes I tow some heavy loads 20K, but when I do I shift it manually with the TCC locksup early unless I shift it manually there fore I can run the r's up a little more with less throttle pressure.

Iam sure you can break the input shaft if your not careful but I try to be gentle when towing those heavy loads, lots of stress on the drivetrain .

In regular driving (not towing) it gets-up and moves!:D
 
For mod like that 2nd lockup i have solution ):h but It is only for obd1 :rolleyes5:
I Have bigger memory chip (enough big for 8 different programs) and switch system which allows changing software version only by pushing button and it has nice LED display showing which version is currently in use. Only bad thing is engine must be turned off before new software works. theorically it should change it engine running, but usually it messes up something in computer memory and throttle goes crazy..:nonod: idle is still there, but it starts jerking when trying to accelerate, but power off and back on and everything works fine again:D. I use it to test different settings while developing my chip with 4K testgroup :grouphug:
 
6.5coalroller said:
Bought the wrong dang switch for my tcc lock up mod guess i need a single pole double throw switch looks a lil complicated.
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Not complicated, just means you have to learn a little it seems :)... Heres my thinking cap, I'm not using it for a few days...

:hat:

Please return when done :thumbsup:
 
Finally got it lol diagram wasnt quite rite on the color codes. I think I need a chip lol it doesnt really take off when I flip it.
 
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