I see a lot of people ask about if it's safe to go past 350whp on a WRX FA20. So decided to write this post on my opinion on it.
The whp doesn't kill the motors the tq does.
Anything above 370tq seems to be the threshold of gambling.
Don't have the mindset that the car won't blow up if you decide to go past that.
I tell most of my customers that when going past 370tq you are rolling the dice each time you do a pull. A Tune will not make it ever blow up. It will, however, decide how long the motor will last at tq levels above 370tq. A bad tune = shorter time the motor will last. A good tune = Longer time the motor will last.
There are A LOT of FA20 WRX's at that 400/400 level or even more and they are fine. You can go 1 mile or 50k + miles.
Bigger Turbos on the stock block, push more power but are safer for the motor due to the late tq rather then the stock turbo and early tq.
Just depends on the Subigods and tune :)