What I know is 3rd gen sti has weaker connecting rod, so the absolute limit is 350whp, but the rest is same as 06-07 sti. subaru had a recall on 08sti, because ecu cause detonation at high rev.

There are still pre08 sti had their piston failed. I think if u r really worried about the reliability, just use aos, thick oil, magnetic drain plug/magnet on oil filter, then drive slowly(ie 10min) before oil temp reaches proper temp and don't hit redline all the time.

My car has 290whp, two of my friends have 310whp and 295whp with factory internals.

PS: handling first is always a good idea if u want to track ur car

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MY08 STI 422whp at 1.5bar on E85, built by Diversion Garage, assembled and tuned by EvoR

Update from new owner: 375whp at 1.4bar on 98, at Tokyo Motorsport