Subaru Impreza Wrx Sti 2011 348Ps 556NM

Since The first Impreza, Subaru is trying to evolve and produce a better and more powerful All wheel drive car. In 2011 this STI (300ps) model was produced using the EJ25 (2.5 liter) engine and a CAN communication system for the electronic part of the engine management system.

Using Tactrix and ecu-flash software we have re-programmed the engine management system (stage 1) and re-calibrated it for higher boost levels and richer mixtures to fit the 98 octane fuel using 1.5 bars of boost.Vmax was removed and boost limiters were raised so the car can do more torque and horsepower on our all wheel drive mustang dyno.

We can see on this diagram the huge difference in the middle rpm range which is given by the 1.5 bars of boost. This car is equipped with 3 inch down-pipe and a free flow air filter but the inter-cooler is stock so keeping high boost levels while having increased intake air temperatures is not wise, so we are dropping the boost while the rpm are getting higher to hit eventually 1.1 bars of boost to the increased at 7200 rpm limiter.

Using the our LM2 Wideband system connected to our dyno we are able to tune accurately every type of fuel or octane rate. All Subaru (boxer) cars are running rich as stock and in our case we kept most of that to the same afr levels to assure that the engine will not knock in any case.

During the development process we kept logging the Afr until we reach the optimal values.This diagram comes just before we finish up with the boost regulation and the new line (brown Afr) is stable and around 10.8 while boosting dropping down to 9.8.Red line is the stock Afr.

The development video here :