Upgraded recirculation valve

Discussion in 'Fiesta ST Engine Upgrades' started by hyatt, Apr 28, 2015.

  1. hyatt

    hyatt Active Member

    So, I know Mountune makes (or made) an upgraded recirc valve for the Focus ST. Does anyone do one for the Fiesta? Are the FoST and FiST valves the same? I ask because I am super interested in getting more of the turbo flutter sound. I'm not into the BOV sound, but the classic turbo flutter sound ala Group C race cars fom the 1980s is, in my opinion, super cool.
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  3. RodMoe

    RodMoe Well-Known Member

  4. hyatt

    hyatt Active Member

    Yeah, definitely not interested in a blow off valve. What I'm looking for is an upgraded recirculation valve, similar to what's already on our cars, but with a stronger spring etc. which gives more of a flutter noise. The Turbosmart wastegate actuator seems like a good deal though! Thanks!
  5. RodMoe

    RodMoe Well-Known Member

    Yup we have used the wastegate actuator on the efr we were playing with and it is a top notch bit.. not sure it gave anymore flutter though and it is still all internal. Look forward to any info if you go this route it will be fun :)
  6. hyatt

    hyatt Active Member

    I'd probably look at the wastegate actuator as more of a reliability mod than anything. Though, if it makes boost response a little snappier and holds boost better and for longer at the top end, I'm all for that. I'll keep you guys posted on what I find regarding an upgraded recirculation valve.
  7. moff3tt

    moff3tt Active Member

    Wouldn't the wastegate actuator you posted be underrated for our cars? It lists 10 and 14 psi models but we go all the way to 22psi if I am not mistaken. Or do I not understand what a wastegate does?
  8. sourskittle

    sourskittle Member

    Stock wastegate is like 5.5psi.

    It basically sets your base wastegate pressure and your ecu uses the wastegate solenoid to control boost higher than that.

    I use a 14psi wastegate on the cyborg turbos ( via a EFR turbo ).

    Tighter wastegate can help spool up, as well as help hold more boost to redline if your stock wastegate is being forced open by too much exhaust pressure.

    I'm not sure the stock turbo can create enough exhaust pressure to over come the 5.5psi wastegate while the boost control solenoid is commanding to to stay closed.

    Cyborg turbo, TBE, panda TR6 intercooler, drop in green filter.
    245whp 293Tq V-dyno
  9. Soldjeepforst

    Soldjeepforst Member

    So i have the turbo smart bov and it has pretty much solved the purging i was getting with the factory bpv. Since im tuned for all low end torque my top end really lacks and i still get purging with in 5th or 6th if im light on the throttle. I have a video on you tube if you guys were wondering what it sounds like on a full bolt on car. If you want flutter well theres an endless supply with that valve. So if i got this waste gate actuator will that assist with keeping boost held instead of purging in the top end?
  10. moff3tt

    moff3tt Active Member

    Ok, so I haven't found an article that explains the function behind the relationship between the boost controller and the waste gate.

    The waste gate has a spring that is set to a specific psi and has a vacuum line (lol, since you know it's a pressure line at that poing) piped to it. How does the pressurized air from the vacuum line going to the waste gate work? I think once I understand this it'll all come together since everything I read just says that the boost controller modifies this signal and that is how it controls the waste gate.

    I did however find out why a stiffer spring will help because even with the aid of a boost controller a spring that is too weak will still begin to open with adequate back pressure being able to over power it.
    Last edited: May 26, 2015
  11. RodMoe

    RodMoe Well-Known Member

    Doesn't the line pressurize the diaphram on the WG to open at a set psi or lbs of boost ? Under vac it is pulled shut via the line but under boost it only holds till the boost overcomes the spring tension.
  12. moff3tt

    moff3tt Active Member

    I found a really good diagram. What I didn't realize was there were two hoses going to the waste gate it makes a lot more sense now.


    So the EBC can "command the waste gate to remain closed" despite it's 10psi spring if it pushes it's valve all the way down in the picture which will cause boost to go into the top of the waste gate aiding the spring in keeping the waste gate closed.
  13. ElijahSky

    ElijahSky New Member

    Did anyone ever find out if the Mountune bpv for a FoST will fit on a FiST?

    Sent from my SM-N910V using Tapatalk

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