Hi mate he's PM'D me back
Hi, if I understand the question right someone wants to put an STI Ecu on a Wrx in the hope of getting more power. That wouldn't work as the STI Ecu will be set up for a completely different engine, turbo, injectors etc. also i believe on subarus of that age the Ecus are coded to the car. But not 100% sure.
I've just copied what he posted for you and basicly what I was saying before. The ECU will be trying to put more power to parts of the car thats not suited, if that makes sense. So would maybe seem ok but would do massive damage to the engine if it even started :)
Hope this helps
And thanks to Gareth at Map-tech in Brigg for the quick reply :)