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4L85E on 4L60 tune w/relay mod-shift table question?

Old May 19, 2013 | 01:43 AM
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Default 4L85E on 4L60 tune w/relay mod-shift table question?

I have a 98 SS with a L92 swap with cam & bolt-ons and Moser 12 bolt with 4.11 gears. Just finished up swapping in a 4L85E & FTI converter replacing the old 4L60E/Circle D conv.

I have HP-Tuners and not much experience using it until a week ago on this swap. I am using the 4L60E tune that was working in the car previous to this swap. I used the "slow67" relay mod to allow the 98 PCM to control the new 4L85E.

I have basically scaled up the WOT & Part throttle shift tables 19% in 1st-2nd gear shifts, and up 9% on the 2nd-3rd gear shifts. I based this on the calculated differences between the 1st and 2nd gear ratios of the two transmissions. I left the shift RPMs at 6500 rpm where they were set as my desired shift point.

Took the car to the track today to make a couple of passes to see how the tranny performed. Everything went well, tranny performed great. BUT, my shift points are still too low. Shifted out on 1st-2nd at 5700 rpms, 2nd-3rd at 6200 rpms. Re-flashed another tune with the shift tables bumped up another 2 mph and still shifting about the same , 5700 & 6200 rpms.

Question: Do I just need to keep raising the mph in the tables until it shifts at my desired 6500 rpms in each gear change? I don't want to make too big of a change and not have it make the upshifts.

Any suggestions, or does anybody have any shift tables that might be a good reference for me to look at?

Thanks in advance

Last edited by floman; May 19, 2013 at 02:10 AM.
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Old May 19, 2013 | 06:41 AM
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This>>> https://ls1tech.com/forums/pcm-diagn...une-4l60e.html


Set down shifts to come in right below max torque, say 4400 and WOT 1mph higher. It will then shift at the rpm you set it at.
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Old May 19, 2013 | 10:52 AM
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Originally Posted by sreve
This>>> https://ls1tech.com/forums/pcm-diagn...une-4l60e.html


Set down shifts to come in right below max torque, say 4400 and WOT 1mph higher. It will then shift at the rpm you set it at.

So, are you saying that I need to determine my WOT downshift mph before I can figure out where to set my upshift mph? I do currently have the downshift mph lower than the upshift @ WOT, but it is 4mph lower on the 1st-2nd shift and 3mph lower on the 2nd-3rd shift. That's how it was set up in the 4L60E tune ( not saying that was correct either, that was done by the previous owners tuner).

I'm not having an issue with hitting the rev limiter, its actually shifting out too early.


I'm not too far off from where I need to be, but am leaving several hundred rpm on the table for each shift. Car ran decent for the first time out, but it will be better if I can attain my 6500 rpm shifts.

I just scaled everything up from the 4L60E tune that was already in the car. Not saying that the tranny tune was correct before. I had very little drive time on the 4L60E combo that was in the car before I started having issues with the tranny. I had just recently purchased the car and soon after began having issues, and at that point decided to go ahead convert to a 4L85E.

I'm very green on the tuning thing. I just did what seemed logical and scaled up the shift tables 19% across the board on the 1st-2nd shift and up 9% on the 2nd-3rd shift as that is the % differences in the gear ratios between the two trannies 1st and 2nd gears.
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