APR Stage III EFR7163 Turbocharger System

Engine Management

Included with the turbocharger system is APR’s world-renowned Stage III ECU Upgrade! This software upgrade installs on the factory ECU and requires no extra end user configuration or tuning and eliminates the need for costly piggyback controlling devices. Simply visit any APR dealer and the software installs in minutes!

APR’s Engineers spent more than a year and a half researching and developing the factory engine management system to operate seamlessly with the extensive changes introduced at Stage III. This includes thousands of full power sweeps on the engine and chassis dynos, street and track.  This was no simple task as power is well beyond the original configuration with extensive hardware changes. Through both ECU source code and calibration changes, APR’s Engineers converted the system to run with a substantially larger turbocharger, featuring a pneumatic wastegate actuator and larger MAP sensors. At Stage III+ power levels, the software supports larger port injectors and a larger fuel pump.

To better understand the complexity of the engine management system, one must first understand the models within. The factory engine management system uses modeled, or simulated input, to control the engine without the need for costly sensors. While some sensors are still used, the ECU does not measure how fast the turbocharger is spinning, temperature of the exhaust gasses, or how much backpressure is in the turbine housing, among many other important things. When developing the factory calibration, sensors were used to measure each of these items and then models were made within the ECU and the sensors were removed. The ECU then relies heavily on expected behavior from factory components. However, if these components are altered, such as changing the turbocharger, the models no longer work and the engine no longer runs correctly. This is why properly created Stage III software is so critical.

To properly configure the ECU, APR’s engineers spent months updating the ECU’s modeled information to the new hardware specifications. While on the engine dyno, various expensive and sensitive probes were installed throughout the engine allowing APR’s engineers to measure and alter critical information within the ECU. When hardware changes were necessary, APR’s Mechanical Engineers were able to make changes, rather than requiring the calibrators to tune around the shortcomings. APR’s incredibly powerful and proprietary ECUx data logging suite allowed APR’s engineers to monitor every change within the ECU at extremely high resolution, ultimately resulting in a calibration that is responsibly created. The ECU fully understands the changes Stage III brings, and as such, can properly manage and control the engine. Because of this, APR’s Engineers can aggressively seek exciting power levels without taking risky shortcuts. The engine operates more smoothly, enhancing everything from daily driving to full-on acceleration. Fuel economy is better and the ECU can properly protect the engine from dangerous operating conditions. To APR’s Engineers, it’s responsible tuning. To the driver, it just works.