I was considering running this pulley and was curious if anybody was running one? If so, then what kind of gains are you getting? I ran a search, but there doesn't seem to be anything mentioned about them. As long as the STi motors are internally balanced, I would imagine that reducing reciprocating mass by 4 pounds would be worth some power.

 

check out the reviews section. Good mod... but the gains are miniscule if any... I feel its worth reducing a bit of strain off the engine... one of those "why not" mods, i guess~!

 

I have my put in kinda like an impulse move. I couldn't really see that much of a gain that allowed me to feel the differences. If anything I think it revs up kinda faster???