Did a 4L80 swap in a 72' Suburban behind a 5.7L engine. Had to do a segment swap for the 4L80. Now the transmission shifts, but it shifts too fast. I have updated the speedometer calibration using the gear/tire wizard, but speedometer is still showing way too fast. I have attached the current tune, and the log. Can someone please take a look and tell me what I am missing? 23-02-09 16-26-09.hpl2001 P01 5.7 Segment Swap 4L80E.hpt
I wonder if it has anything to do with you starting off with the corvette operating system. Those use a transaxle and not a standard transmission.
2016 Silverado CCSB 5.3/6L80e, not as slow but still heavy.
If you don't post your tune and logs when you have questions you aren't helping yourself.
I didn’t think about that. Anything I can do to fix that? Using this same PCM?
The setting for Pulses Per Rev (the number of teeth on the thing being read by the sensor) does not always follow the tooltips in the editor - it says it'll accept a range of 0 to 256, but the actual range each OS is able to use is often much narrower range.
If its showing speed when you rev in neutral the two vss plugs are swapped
Is there anything I can try to get it closer to reality?
No it is not. Just tried that.
If it's shifting too fast then it's probably not getting the correct speed inputs - most likely missing the TSS
Add TSS (turbine shaft speed input) and VSS (Vehicel speed input) all to your log. TSS should be present and match rpm with the engine running then vss should be changing with the vehicle rolling. If you're missing one of these then you're missing one of your inputs (either wired to the wrong pins/wrong connector at the ecm) or hooked to the wrong sensors. You should be plugged into the front TSS speed sensor and tailshaft (VSS speed sensor) plugs. The center (tss output) speed sensor should be bare or not have a wire going to it. You should have also had to either install a plug and play harness or ran two new wires to your ECM for the tss input.
2010 Vette Stock Bottom LS3 - LS2 APS Twin Turbo Kit, Trick Flow Heads and Custom Cam - 12psi - 714rwhp and 820rwtq / 100hp Nitrous Shot starting at 3000 rpms - 948rwhp and 1044rwtq still on 93
2011 Vette Cam Only Internal Mod in stock LS3 -- YSI @ 18psi - 811rwhp on 93 / 926rwhp on E60 & 1008rwhp with a 50 shot of nitrous all through a 6L80
~Greg Huggins~
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2wd or 4wd?
4wdOriginally Posted by RDF1
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