We have developed a standalone-like air-fuel ratio targeting system for boosted M30 and M20 engines using the factory ECU! The Miller Variable Closed Loop Control System allows the factory ECU to target two different air fuel ratios for on and off boost conditions. Just like factory, when you are at idle or part throttle without boost, your WAR Chip powered factory ECU will target 14.7:1 for maximum fuel efficeincy. Under boost though, we have programmed our VCLC system to change the target air fuel ratio so that the ECU is always able to manage and maintain a safe fuel curve regardless of temperature, heat soak, or boost ramp.
The VCLC system uses the AEM built wideband/boost gauge combo to interact with the WAR Chip. This trigger is set at 4 PSI . The Air fuel ratio under boost is user programmable. The system does such a good job at maintaining in boost air fuel ratios that it is almost like a standalone self tuning feature.
On top of that, we have also be able to bring a useable boost signal to the factory ECU for the first time! We have recalibrated aspects of the engines operating code to use a boost signal input to help maintain safe operation with different boost ramps. Boost will come on differently in every gear and at different engine loads. Now, the VCLC system makes the factory ECU seem like it was intended for a boosted setup!