I’ve had my Fiesta ST for a little over a year now. During that year I didn’t modify anything until the very end when I installed Fifteen52 Turbomac wheels and a used Cobb Accessport. Fast forward to February 2018 and I received a Boomba BPV Spacer as a gift. If you don’t already know the difference between a BPV and a BOV I suggest reading our BPV vs BOV article.
Right off the bat, you may be wondering what the purpose of the BPV spacer is, and the short answer is that there is not a purpose. Realistically on a street car, you want to recirculate all the air back into the intake for the best possible throttle response and to minimize turbo lag(not turbo threshold). This little spacer takes your 100% recirculating bypass valve and makes it work like a 100% VTA blow off valve. The entire purpose of this part is to increase the volume of that“PSSH” noise. As far as performance goes, this part does not add any performance to your Fiesta ST.
In the past, I’ve always worked on old Jeeps or trucks, and I’ve always dreaded installing anything on a newer car, as everything in the engine bay is hard to reach. Unfortunately, the Fiesta ST has a pretty cramped engine bay. Luckily, the stock bypass-valve can be accessed through the passenger wheel well fairly easily.
Start by loosening the lug nuts on your front-passenger wheel, then jack up the ST, and then remove the front passenger wheel. At this point, you will need a 5mm Allen head socket. I attempted using a small Allen wrench hoping that it would work, but it really doesn’t. A ball-headed 5mm Allen socket works best, especially when used with some extensions. Unplug the bypass-valve and remove the three bolts holding it on. Carefully remove it from the vehicle. The Boomba Racing spacer can only go on one way, so align it with the bypass-valve and re-install both into the factory location using the provided hardware. Plug the bypass valve in and test fire the vehicle. Get your car into boost and make sure the valve properly opens with no turbo flutter (a sign that you didn’t plug the BPV back in)
I already had an Injen intake on my Fiesta ST which made the stock bypass-valve quite a bit louder than if I were to have the stock intake. Since this spacer forces all the air out under the engine bay, the sound is quite a bit louder, especially from outside the vehicle. There are actually quite a few ST owners that I know personally who ended up uninstalling their BPV spacer, claiming the extra noise had become annoying. As for myself, I do indeed find it to be almost too loud, but not quite. It’s loud enough to scare pedestrians and piss off your neighbors, but my exhaust already does that so this isn’t anything new for me. Be sure to check out the video below!