Cruze throttle closing during WOT

[GroovinJim]

Hello folks. I'm tuning a 2014 Chevy Cruze 1.4 turbo car for a friend. I'm admittedly a bit out of my element with the E78 controller and looking for some guidance.

Fueling seems to be dialing in OK but under WOT the throttle suddenly and consistently closes down to ~49%. It feels like it is hitting some sort of torque limit but I can't put my finger on it. Wondering if someone would look at the tune and logs and perhaps point me in a direction?

Thank you,

Jimmy

[KillboyPowerhead]

Try logging all available torque-related parameters. Believe Engine Torque/Delivered Engine Torque needs to be less than Maximum Engine Torque or else the throttle will close. Peak Torque needs to be greater than Max. VVE (and I imagine MAF) calibration has a lot to do with torque calculations and thus your Engine/Delivered Torque. Driver Demand tables also play a role (Predicted Torque?).

Edit: typo.

[shartwig.27]

Hello folks. I'm tuning a 2014 Chevy Cruze 1.4 turbo car for a friend. I'm admittedly a bit out of my element with the E78 controller and looking for some guidance.

Fueling seems to be dialing in OK but under WOT the throttle suddenly and consistently closes down to ~49%. It feels like it is hitting some sort of torque limit but I can't put my finger on it. Wondering if someone would look at the tune and logs and perhaps point me in a direction?

Thank you,

Jimmy

So your running into the same issue i was with my sonic 1.4t car. Had the same problem with my car above 5100 rpm where the boost fluctuates like crazy and the throttle closes halfway. The limit you're running into is the Pressure Ratio Max. Go to Engine>Airflow>Turbocharger. You need to increase the MAF numbers appropriately for the increased flow and boost. I went from 19.5lbs/min to 23lbs/min from left to right on the column axis, then I increased the pressure ratio numbers under the MAF numbers 3.00 to 2.60 since I'm only tuned on 20psi of boost. This table basically limits boost and airflow to prevent the turbo from spinning too fast and causing an compressor/turbine wheel failure. Id say if he's aiming for 20psi of boost, these numbers should be fairly close to what he wants. The big one is the pressure ratio numbers themselves, you shouldn't have to rescale the MAF columns too much unless you are running a hybrid turbo or a full frame turbo with a custom turbo manifold and still using the stock boost controller.