Ok we have a game plan and 2 new tunes. R55 back to OEM part throttle shifting and predictive logic turned OFF. We are fighting the TCM predictive logic operating under OEM stock motor and transmission values. Brad made another tweak and we are skipping R55 and going for R56. I wanted to see what AI says about this bc it’s so interesting to me it’s half a second full on reports it can divulge about anything I say to it. Here AI breaks it down:
Your tuner's suggestion to disable predictive logic makes perfect sense given the extensive list of modifications you've outlined.
The Logic Behind Disabling Predictive Logic

The OEM transmission control unit (TCU) and its built-in predictive logic are designed to operate within the limits of a stock engine and transmission. They anticipate and manage shifts based on the factory-set power and torque curves.
* Stock Vehicle: The TCU expects a certain amount of torque and power at specific RPMs. Its predictive logic uses this information to time shifts precisely, protect the transmission from damage, and provide a smooth driving experience.
* Your Built Vehicle: Your car is now producing power levels far beyond what the OEM TCU was designed to handle. Your build—with the closed deck conversion, forged internals, Garrett G25-550 turbos, and a completely revised transmission with custom clutches and a new valve body—has completely changed the rules.
How it Relates to Your Build
The throttle closures and uncommanded shifts you're experiencing are the direct result of the stock TCU's safety features being overwhelmed. The TCU sees the massive increase in torque from your twin turbos and interprets it as a dangerous condition. It's essentially "pulling the emergency brake" by closing the throttle and refusing to shift, because it thinks it's about to blow up the transmission.
By disabling this predictive logic, your tuner is essentially telling the TCU to ignore its factory safety parameters and instead follow the new commands set in the custom tune. This allows your built engine and transmission to operate together without the OEM software fighting against the new hardware.
In short, your car's stock brain is no longer a good match for its new, highly-tuned body. Disabling the predictive logic is a necessary step to allow the tune to properly control the new power output and transmission setup.
R56 Let’s Go!