Originally Posted by chitownej
I thought you meant splitter as in when you're looking at hood scoop there's those rows like the 4 or 5, that's what I thought you were talking about, I get that it'd the black piece behind there....hopefully I can modify it to work how do ya do that??
The splitter is a horizontal plane that attaches under the scoop and behind the vertical vanes at the mouth. IIRC the WRX doesn't really have a splitter. It's not needed with the smaller TMIC.
The splitter's purpose is to direct airflow evenly over the intercooler. Without it the air would pile up at the back of the scoop and not flow over the entire intercooler. Just FYI, your hood scoop is the same as the STI for your year, so you don't need to replace it. The splitter and the boot (that seals around the intercooler when the hood is down) can be had at subarugenuineparts.com.