would it hurt to use it on my stock civic si...

wats good and bad about it... anything that you have to tell me.

 

No it will not hurt at all....just make it installed by a good mechanic and tune it on a dyno.....I would not recommend a VAFC on a stock Si......keep ur money and buy yourself a bunch of performance parts and THEN get the VAFC.....cuz you'll need to tune it everytime u change sumethin in your engine...sucks @ 100$ dyno hour...............