18 ZL1 1LE M6 aftermarket gear ratio adjustment

Been pulling my hair out on this and looking for anyone's insight if available. We put a PPG gearset in an 18 ZLE with different gearing than the stock ZL1 or ZLE. The gear ratios are close enough in 1-3 that they dont cause any issues but in 5th and 6th the car is getting a clutch slip detected message and pulling power. The stock ZLE 5th is .82 and 6th is .675. Our new gear ratios are .91 in 5th and .75 in 6th. I have changed the gear ratio tables in manual transmission section and it does not have any effect. I have even set them to 1.00 for 5th and 6th and the rev matching does not change. I have also disabled the clutch slip code P17A2. Regardless of what I change the issue stays the same. Have ran it past PPG and they have been little help. Anyone on here run into something similar? Thanks in advance!

Hey,

So i dug into this some.
There are 2 places in the calibration that have gear ratios stored.
Ones is available through HPtuners

The second, I did not dig into to confirm it is in fact gear ratios. but on 3 test files i have they all lined up correctly.

Im attaching a tune with the second set of gear ratios changed
Please tread lightly with this tune, im only like 80% sure that what i adjusted was gear ratios

Attachment 136466

If this works or doesnt, please update

I have had the same issue more or less. I did a transmission swap from a C7 GS M7 to Z06 M7 gearbox on my Katech C7GS . I changed the ratios in the table and it does not work. Only thing that worked was to disable the transmission shaft speed sensor. But then you loose Rev Match and Cruise control. Been like that for 2 years on my car. I do not care too much for those 2 features as I mainly use the car on Roadcourse. PTM still works. I have several topics on the forum about this and contacted HP tuners about their ratio table that does not work. never got an answer.

i can fix it. no need to disable anything.

Yes, this is completely tunable without having to disable anything.

I'm thinking about a transmission swap (2019 Corvette Grand Sport going to a Z06 transmission). After breaking the same ankle in 3 places twice (hockey), I can't heel/toe so I need active rev match. Is there a tutorial on how to get to the other table(s)?