Yes, it is normal to have an increase in sound from the intake and the BOV or 50/50. Your engine went from sucking air through a straw to sucking it through a wind tunnel. The stock intercooler is very restrictive.
1 - 4 of 4 Posts
This is an older thread, you may not receive a response, and could
be reviving an old thread. Please consider creating a new thread.
We’re the premiere Ford Focus ST forum with discussions on the 2013+ Focus ST. Join the community and see the latest news, photos, videos, classifieds, reviews, events and more!