S550 w/ Tremec OSS issue

Any suggestions?!

We have a 2017 Mustang roush 670 supercharger w/LT HF Cat headers with a Tremec Transmission upgrade that came from another shop but since the transmission upgrade customer have many issues... Rpm going up when clutch is depressed, no cruise control on 1,2,5 and 6th gear and power reduced in first and second gear when pushed hard. We did install the Abott Era box and OSS vs VSS was calibrated in 4th gear (1:1) so they match each other. Many calibration have been done by a renowned tuner but with no success. We are out of luck and really open to any advise. 🙋

post a tune

Here is the Roush original file w/ turned off O2 and the last calibration from my tuner.

Attachment 83333Attachment 83332

You need to address your gear ratios in tune. Tremec offers few different ratios - make sure you have those right.

Like Veefour said. Adjust gear ratios to match transmission used. Make sure they fall between the min and max settings. Should be good assuming rest of the tune is correct.

Can the VSS and each gear ratio values be changed with the HP tuner on a 2015 Mustang? Thanks!

yes, go to speedo section then under calibration is the transmission stuff

.Attachment 94531