
Originally Posted by
Egan101
There are aftermarket ECU tunes that follow factory settings. You could bring up the XT output similar to the WRX, same way bringing the WRX output to S4. These are safe ECU tunes. However, bringing the output to higher levels may result to some unnecessary strain and potential failure. For the CVT-equipped FA20-powered cars, the 300hp/400Nm is a safe max tune due to the torque limit of the CVT tranny.
With the older EJ25 turbo engines (WRX STi, Legacy GT), there are a lot of aftermarket tunes that bring the output to around 400hp. Not sure though how it impacts reliability.