For now a manual boost controller was installed to keep the turbo under control. The USDM ECU also does not have boost control but we are going to change that in the future. The USDM NA ECU uses a speed density fuel calculation instead of MAF and also has a Bosch LSU 4.2 wideband front O2 (lambda) sensor from the factory so that needs to be taken into account when doing the swap. Both come with a 32-bit ECU although the JDM runs on a mass airflow sensor, has different harness connectors and does not support OBD2 protocol.

A lot of the sensors and wiring are shared between these 2 engines despite the fact that one is turbocharged and the other is not. Other suitable candidates are the EJ207 and EJ205 from the Impreza GC8 and GF8 WRX/STI. With the engine harness connectors being nearly the same, the swap becomes almost a plug and play affair.įor this build, an EJ205 from a JDM Forester SF5 was swapped in to replace the original EJ251. Here you can see how it can be done without the wiring hassle by keeping the EJ251 ECU and using our projectLAMBDA Tuner to get it to play nice with the turbo engine. Typically the donor turbo engine was not compatible with the factory EJ251 ECU and required a complicated wiring harness merge to get the car running on a swapped-in turbo ECU. The Subaru Impreza 2.5RS sedan and coupe have been a popular platform for turbo swaps for a while now. MY2000 Impreza EJ251 ECU Running a Turbocharged EJ205

Subaru jdm engine 2.5i