A search is seeming to bring up 220-230 whp for a stock STi.

 

It all depends on the dyno doing the measurment. I'm sure if you put a stock STi and a stock EVO on the same dyno, the STi would probably have more whp.

Check out this thread http://www.tripleplate.com/vbulletin...ead.php?t=4934

Its got the stock EVO (blue line on the first graph) and stock STi (any line on the second graph) on the same dyno. This dyno (which reads conservatively compared to others out there) has got the EVO at about 207whp and the stock STi at 218whp

 

Check Vishnu's site, I know they have some dyno results on there. Look out for baseline runs