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Discussion Starter · #1 ·
2017 GTR
3”intake
Catless y pipe
Cobb stage 2 OTS MAP
COB TCM optimized shifting tune

Normal mode automatic shifting

I didn’t like the OTS map for optimized shifting so I uninstalled the tcm tune completely to go back to factory and upshifting gear 2,3,4,5 in automatic mode releases the gear revs up and clunks hard in to the next gear and you can hear the transmission working gears trying to get right. That was concerning so I did the gear learn and drive 60 miles for the tranny relearn. Still really bad. Then in 3rd gear if you step on it with 50% pedal or more it goes in to limp And you can floor it and it won’t leave 4th and like 3000rmp until you get off the gas break and down shift then it’s resets and will speed off.

Then I reinstalled the Cobb optimized shifting upshifting from gear 2,3,4 it releases the gear the revs up and mashes into the next gear?

Both tunes only do this between 20%- 50% acceleration pedal. Any lower and it’s smooth and when You step on it it’s smooth too so wtf? Also manual mode in all ranges shifts flawlessly
 

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Just guessing...

That there's something else playing into your situation beyond the TCM map, such as your add-on equipment and the ECU map.

Alexd
 

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Sounds like the ecu tune and not the TCM tune to me.
 

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Discussion Starter · #5 ·
Just guessing...

That there's something else playing into your situation beyond the TCM map, such as your add-on equipment and the ECU map.

Alexd
Hey. Maybe the ecu map but I ran the car with the add ons stage one map and optimized shifting without issues for a few months. It wasn’t till I uninstalled the tcm that the issues began. Do have some insight as to how the 2 things mentioned May play a role here? Or why ecu and not tcm?
 

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Hey. Maybe the ecu map but I ran the car with the add ons stage one map and optimized shifting without issues for a few months. It wasn’t till I uninstalled the tcm that the issues began. Do have some insight as to how the 2 things mentioned May play a role here? Or why ecu and not tcm?
There are look-up tables on the ECU Mapping that the transmission must use.

Alexd
 
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