wrx19

Ok, so I am a n00b with FD's. But not a n00b in the turbo game. My previous car (and love) was a DSM. They have the BOV located in one spot on the intercooler pipe just before the connection to the throttle body.

Where is the stock BOV on the FD? and why do people have the BOV mounted in so many damn different places on their modded FD's? Is there a difference in performance/sound/etc. when you mount it somewhere else? \

I was hitting brick walls when it came to this question, maybe I just suck at searching. Anyway hopefully you trusty FD owners can answer these for me...And if it calls for it, let the flaming begin.

-taylor

rynberg

There are two valves -- the CRV (charge relief valve) and the ABV (air bypass valve). The ABV serves the purpose of the traditional BOV and is located about six-inches upstream of the airbox in the OEM setup. It's about 2-inches in diameter and looks like brown plastic.

wrx19

I thought that when you let off the throttle, the throttle body closes, and then air comes back through the intercooler piping, which is why the BOV (or ABV in this case) would be located on that side of the piping. If the ABV is just up from the air box, then wouldnt the air coming back from the throttle body have to pass through the turbos first to be vented??? I thought the ABV would have to be on the other side of the turbo?

This is like my last step in fully understanding rotaries on a basic level....im sooo close!

rynberg

I was giving you the physical location....the ABV is fed from the y-pipe, which is just downstream of the turbos, so yes, the ABV is between the turbos and IC. The ABV then discharges into the stock airbox to reduce noise (and oil-misting). The ABV receives its vacuum/pressure source from the UIM.