Today I raced my brother's 09 stock wrx with the 2.5 block with my 05 wrx 2.o, I have header, uppipe, exhaust, intake, and bov.
We ran 2 times from 35 and I won both times, his is more powerful at low rpm, but I think with my exhaust opened up more my third gear pulled on him pretty good. But I pulled about half a car in 2nd and beat him good in 3rd.
Modded vs. stock modded normally taked the prize.
Just letting you all know.