Comparing the sound of the Focus ST before and after the Sound Symposer Delete Kit + my thoughts on the BOV after the install.
There is definitely a difference in the sound of the car with the delete kit (although its kind of difficult to pick up on the GoPro audio). The volume of the engine + exhaust is the same, however the frequency of the sound is slightly different. When the sound symposer is activated (which comes on around 3,000 rpms) it injects "extra" sound via a tube from the intake box through the firewall and into the cabin. This sound is very prevalent in a stock Focus ST and super noticeable (I definitely liked it when I first purchased the car and thought it was cool.)
Once you add an exhaust to the car it becomes more difficult to hear this extra sound from the sound symposer - which is why many Focus ST owners advise to delete it (and for the option of running a true vacuum.) One thing I really like about the delete kit is the elimination of the mixture of frequencies between the intake sound and the exhaust sound making the car sound more "raw" or "real".
The BOV does slightly change with the delete kit installed (as mentioned in the video) but does not take away from the pure loudness of the BOV (I'm running the Turbosmart 50/50 Dualport). All I have noticed is that the BOV goes off a bit less when under no boost and driving very slow which was caused by very small shifts in my foot on the gas pedal before. I like that the delete kit has caused this and in my opinion this in of itself is wort the $25 or $30 for the kit.
The website I used to purchase the Sound Symposer Delete kit seems to be out of stock and cannot find the link - so here are some other options (that are identical to the one I purchased):
Steeda with Boost Port $35
www.cjponyparts.com/steeda-so...
COBB with Boost Port $45
www.cjponyparts.com/cobb-soun...
Steeda without Boost Port $30
www.cjponyparts.com/steeda-so...
Current Mods on the Focus:
COBB Cold Air Intake, Borla Catback Exhaust, Cobb Accessport, Stage 2 Tune on 91 Octane, Mishimoto Front Mounted Intercooler, Turbosmart BOV, Rally Innovations Front Splitter 3-Piece Matte Black Aluminum, Fully Torqued Racing adjustable splitter support rods 7.5-9.25in with upgraded hardware, RokBlokz Mudflaps in Orange, DMB UK Replacement ST Badges (in gloss orange), Fanatic Wraps Emblem Overlays (Ford Emblem on Focus ST in Orange w/ carbon fiber background), Velossa Tech Big Mouth Snorkel in Orange, Boosted Designs ST Dead Pedal, Option Lab 10 Spoke Onyx White Wheels 18x8.5 40mm offset, Velossa Tech Wing Riser Kit with Orange Spacers. Geartronics Dynamic Blinker Led Turn Signal Lights Smoked. ACCELATEC Sound Symposer Delete Kit with boost port option.