454 411 Swap

[SS2win]

Could be but mine's doing ok (except for shifts in 4LO). I've never tried 12208322 to know any difference.

[Supercharged111]

Oh yeah, dammit. That must have been the reason. This thing hauls a lot so 4LO may be of use off road with the monster camper.

[SS2win]

I'm going to play with some segment swaps options and see if I can get it to work. just looking for a free Saturday morning..

[Supercharged111]

I'm going to play with some segment swaps options and see if I can get it to work. just looking for a free Saturday morning..

I have a full tune laying around somewhere, just do a full flash after the COS is working and that should be it I do believe. Of course copy/paste your stuff into it. I think it's on the HDD that took a dump but still has recoverable data but my toaster looking thing you stick HDDs into quit working.

[SS2win]

I finally got some time to play with it and got 4LO working. I wish I had taken better notes but in the end the difference is in BOTH the System Segment AND the Calibration. I found the system segment 9373409 enabled 4Lo shifting with the right calibration.... what the final combo is I don't know except that it works now with the 12212156 OS. My guess is there is a 4LO shift table that is not populated in some calibrations.

Next problem to tackle is converter lockup. It used to work but hasn't in some time and I don't know what I changed to break it!

[Supercharged111]

Hmm, I much like the idea of a system segment swap only on my 1500, that would allow me to keep everything else working. Can you jam that directly into COS5 or do you first need to un-COS, add the segment, and re-COS?

[SS2win]

I'm not using a custom os so no experience there. I'd guess that you can segment swap as normal. From what I found, you have to have the proper system segment AND a calibration that is ready with the 4LO shift table populated, or it won't work. I'm making a grand assumption that there are calibrations without the 4LO table data, and that, in combination with the wrong system segment, is breaking 4LO shifting. Somehow I hit on the right combination. I can flash an older tune on to the OS I'm using and break 4LO shifts.,,,

[Supercharged111]

Weird. I remember the combo being sort of magical. I believe the S10 was a part of the secret sauce. So a cal only flash will break 4LO? That's crazy.

[SS2win]

Yep! I also found that I can flash a 6.0L 4l80E tune in, set the platform to GM610 and set the low res crank option and that's all you need for a vortec. In other words you don't need to start with a Express van tune if you know what to set in system. I never questioned that before but in my attempts to get 4LO working I flashed a 2002 6.0L OS and then flashed my "vortec" tune over that. Fired right up. Somehow along the way of mixing and matching tunes and segment swaps I got the (invisible) 4LO shift table copied in there which enabled shifting. works perfect now.

[Supercharged111]

Sweet! What table is the low/hi res crank option?